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• CodePlex Daily Summary for Wednesday, November 23, 2011

  CodePlex Daily Summary for Wednesday, November 23, 2011Popular ReleasesVisual Leak Detector for Visual C++ 2008/2010: v2.2.1: Enhancements: * strdup and _wcsdup functions support added. * Preliminary support for VS 11 added. Bugs Fixed: * Low performance after upgrading from VLD v2.1. * Memory leaks with static linking fixed (disabled calloc support). * Runtime error R6002 fixed because of wrong memory dump format. * version.h fixed in installer. * Some PVS studio warning fixed.NetSqlAzMan - .NET SQL Authorization Manager: 3.6.0.10: 3.6.0.10 22-Nov-2011 Update: Removed PreEmptive Platform integration (PreEmptive analytics) Removed all PreEmptive attributes Removed PreEmptive.dll assembly references from all projects Added first support to ADAM/AD LDS Thanks to PatBea. Work Item 9775: http://netsqlazman.codeplex.com/workitem/9775Developer Team Article System Management: DTASM v1.3: ?? ??? ???? 3 ????? ???? ???? ????? ??? : - ????? ?????? ????? ???? ?? ??? ???? ????? ?? ??? ? ?? ???? ?????? ???? ?? ???? ????? ?? . - ??? ?? ???? ????? ???? ????? ???? ???? ?? ????? , ?????? ????? ????? ?? ??? . - ??? ??????? ??? ??? ???? ?? ????? ????? ????? .SharePoint 2010 FBA Pack: SharePoint 2010 FBA Pack 1.2.0: Web parts are now fully customizable via html templates (Issue #323) FBA Pack is now completely localizable using resource files. Thank you David Chen for submitting the code as well as Chinese translations of the FBA Pack! The membership request web part now gives the option of having the user enter the password and removing the captcha (Issue # 447) The FBA Pack will now work in a zone that does not have FBA enabled (Another zone must have FBA enabled, and the zone must contain the me...SharePoint 2010 Education Demo Project: Release SharePoint SP1 for Education Solutions: This release includes updates to the Content Packs for SharePoint SP1. All Content Packs have been updated to install successfully under SharePoint SP1SQL Monitor - tracking sql server activities: SQLMon 4.1 alpha 6: 1. improved support for schema 2. added find reference when right click on object list 3. added object rename supportBugNET Issue Tracker: BugNET 0.9.126: First stable release of version 0.9. Upgrades from 0.8 are fully supported and upgrades to future releases will also be supported. This release is now compiled against the .NET 4.0 framework and is a requirement. Because of this the web.config has significantly changed. After upgrading, you will need to configure the authentication settings for user registration and anonymous access again. Please see our installation / upgrade instructions for more details: http://wiki.bugnetproject.c...Anno 2070 Assistant: v0.1.0 (STABLE): Version 0.1.0 Features Production Chains Eco Production Chains (Complete) Tycoon Production Chains (Disabled - Incomplete) Tech Production Chains (Disabled - Incomplete) Supply (Disabled - Incomplete) Calculator (Disabled - Incomplete) Building Layouts Eco Building Layouts (Complete) Tycoon Building Layouts (Disabled - Incomplete) Tech Building Layouts (Disabled - Incomplete) Credits (Complete)Free SharePoint 2010 Sites Templates: SharePoint Server 2010 Sites Templates: here is the list of sites templates to be downloadedVsTortoise - a TortoiseSVN add-in for Microsoft Visual Studio: VsTortoise Build 30 Beta: Note: This release does not work with custom VsTortoise toolbars. These get removed every time when you shutdown Visual Studio. (#7940) Build 30 (beta)New: Support for TortoiseSVN 1.7 added. (the download contains both setups, for TortoiseSVN 1.6 and 1.7) New: OpenModifiedDocumentDialog displays conflicted files now. New: OpenModifiedDocument allows to group items by changelist now. Fix: OpenModifiedDocumentDialog caused Visual Studio 2010 to freeze sometimes. Fix: The installer didn...nopCommerce. Open source shopping cart (ASP.NET MVC): nopcommerce 2.30: Highlight features & improvements: • Performance optimization. • Back in stock notifications. • Product special price support. • Catalog mode (based on customer role) To see the full list of fixes and changes please visit the release notes page (http://www.nopCommerce.com/releasenotes.aspx).WPF Converters: WPF Converters V1.2.0.0: support for enumerations, value types, and reference types in the expression converter's equality operators the expression converter now handles DependencyProperty.UnsetValue as argument values correctly (#4062) StyleCop conformance (more or less)Json.NET: Json.NET 4.0 Release 4: Change - JsonTextReader.Culture is now CultureInfo.InvariantCulture by default Change - KeyValurPairConverter no longer cares about the order of the key and value properties Change - Time zone conversions now use new TimeZoneInfo instead of TimeZone Fix - Fixed boolean values sometimes being capitalized when converting to XML Fix - Fixed error when deserializing ConcurrentDictionary Fix - Fixed serializing some Uris returning the incorrect value Fix - Fixed occasional error when...Media Companion: MC 3.423b Weekly: Ensure .NET 4.0 Full Framework is installed. (Available from http://www.microsoft.com/download/en/details.aspx?id=17718) Ensure the NFO ID fix is applied when transitioning from versions prior to 3.416b. (Details here) Replaced 'Rebuild' with 'Refresh' throughout entire code. Rebuild will now be known as Refresh. mc_com.exe has been fully updated TV Show Resolutions... Resolved issue #206 - having to hit save twice when updating runtime manually Shrunk cache size and lowered loading times f...Delta Engine: Delta Engine Beta Preview v0.9.1: v0.9.1 beta release with lots of refactoring, fixes, new samples and support for iOS, Android and WP7 (you need a Marketplace account however). If you want a binary release for the games (like v0.9.0), just say so in the Forum or here and we will quickly prepare one. It is just not much different from v0.9.0, so I left it out this time. See http://DeltaEngine.net/Wiki.Roadmap for details.ASP.net Awesome Samples (Web-Forms): 1.0 samples: Demos and Tutorials for ASP.net Awesome VS2008 are in .NET 3.5 VS2010 are in .NET 4.0 (demos for the ASP.net Awesome jQuery Ajax Controls)SharpMap - Geospatial Application Framework for the CLR: SharpMap-0.9-AnyCPU-Trunk-2011.11.17: This is a build of SharpMap from the 0.9 development trunk as per 2011-11-17 For most applications the AnyCPU release is the recommended, but in case you need an x86 build that is included to. For some dataproviders (GDAL/OGR, SqLite, PostGis) you need to also referense the SharpMap.Extensions assembly For SqlServer Spatial you need to reference the SharpMap.SqlServerSpatial assemblyAJAX Control Toolkit: November 2011 Release: AJAX Control Toolkit Release Notes - November 2011 Release Version 51116November 2011 release of the AJAX Control Toolkit. AJAX Control Toolkit .NET 4 - Binary – AJAX Control Toolkit for .NET 4 and sample site (Recommended). AJAX Control Toolkit .NET 3.5 - Binary – AJAX Control Toolkit for .NET 3.5 and sample site (Recommended). Notes: - The current version of the AJAX Control Toolkit is not compatible with ASP.NET 2.0. The latest version that is compatible with ASP.NET 2.0 can be found h...Microsoft Ajax Minifier: Microsoft Ajax Minifier 4.36: Fix for issue #16908: string literals containing ASP.NET replacement syntax fail if the ASP.NET code contains the same character as the string literal delimiter. Also, we shouldn't be changing the delimiter for those literals or combining them with other literals; the developer may have specifically chosen the delimiter used because of possible content inserted by ASP.NET code. This logic is normally off; turn it on via the -aspnet command-line flag (or the Code.Settings.AllowEmbeddedAspNetBl...MVC Controls Toolkit: Mvc Controls Toolkit 1.5.5: Added: Now the DateRanteAttribute accepts complex expressions containing "Now" and "Today" as static minimum and maximum. Menu, MenuFor helpers capable of handling a "currently selected element". The developer can choose between using a standard nested menu based on a standard SimpleMenuItem class or specifying an item template based on a custom class. Added also helpers to build the tree structure containing all data items the menu takes infos from. Improved the pager. Now the developer ...New ProjectsActiveWorlds World Server Admin PowerShell SnapIn: The purpose of this PowerShell SnapIn is to provide a set of tools to administer the world server from PowerShell. It leverages the ActiveWorlds SDK .NET Wrapper to provide this functionality.Aigu: Enter special characters like you would on your mobile phone. For instance, if you want to type 'é', you just hold down 'e' and a menu will appear. Selected the desired character using the arrow keys and press 'enter'. Simple but powerful.Are you workaholic?: Are you a workaholic? Did your Doctor advice you not to stare at the computer monitor for a long time? Then this app is perfectly made for you. It runs in the background, and alerts you to take periodic rests for your eyes and body. What's more, It's open source (MS-PL).ATDIS PoC: privateAuto Version Web Assets: The AVWA project is an HTTP Module written in C# that is designed to allow for versioning of various web assets such as .CSS and .JS files. This allows you to publish new versions of these files without having to force the server or the client browsers to expire cache.Bachelor Thesis Algorithm Test Bed: Algorithm Test Bed for my Bachelor ThesisBase64: Simple application helps converting strings and files from or to Base64 string. You can use any encoding to convert while a sidebar previews decoded string for all other encodings.BoracayExpress: BoracayExpressC++ Framework for Test Driven Development: A testing framework for C++ written in C++.Class2Table: Class2Table aka Entity2Table. Easy tool that allows creation of SQL tables from .Net types.Code for Demos & Experiments: This is where I will post code from demos and presentationsCodeMaker: CodeMaker?????????： 1、?????????? 2、???? 3、????? 4、??Python????????? ConsoleCommand: ConsoleCommand provides certain .Net commands for access from javascript console engines. Included are commands to set the text and background colors, as well as list and extract resources compiled in a .Net dll. Converter: Character code conversion tools ???????? CryptoInator - self contained, self-encrypting, self-decrypting image viewer: Original developed to encrypt and store NemID images in Denmark. DAiBears: Something, something, botDelicious Notify Plugin: Lets you push a blog post straight to Delicious from Live WriterDeveloperFile: Compresses Javascripts using the YUI .NET project. Loops through the root folder and subfolders for files matching the debug extension and creates new files using the release extension. (File extensions must match exactly).DotNetNuke SharePoint File Explorer: A DotNetNuke SharePoint File ExplorerDouban FM: WP7 Douban FM appGame Lib: Game Library is a open-source game library to allow focusing on the fun part of a game. It is developed in C#, but will be ported to C++ and VB.net.Google reader notes to Delicious Export tool (WPF): Google reader discontinued note in reader features. Current google reader allows to export users old notes in JSON format, This App will parse the JSON file & upload it to it delicious , delicious is a good alternative for note in readerHtml Source Transmitter Control: This web control allows getting a source of a web page, that will displayed before submit. So, developer can store a view of the html page, that was before server exception. It helps to reproduce bugs and can be used with other logging systems.Ideopuzzle: A puzzle gameImageShack-Uploader: This project demonstrates how to upload files automated to imageshack.us and other image hosters with C#.Insert Acronym Tags: Lets you insert <acronym> and <abbr> tags into your blog entry more easily.Insert Quick Link: Allows you to paste a link into the Writer window and have the a window similar to the one in Writer where you can change what text is to appear, open in new window, etc.Insert Video Plugin: Allows you to insert a video into a blog entry from a multitude of different sitesIoCWrap: Provides a wrapper to the various IoC container implementations so that it is possible to switch to a different provider without changing any application code.kaveepoj: sharepoint projectKinect Quiz Engine: Fun quiz game for the Kinect.Klaverjas: Test application for testing different new technologies in .NET (WCF, DataServices, C# stuff, Entity...etc.)Man In The Middle: A cyberpunk themed action with puzzle and strategy elements. Made with XNA as part of a game development course at the IT University of Copenhagen by Bo Bendtsen, Jonas Flensbak, Daniel Kromand, Jess Rahbek & Darryl Woodford.MediaSelektor: Simple tool to select mediasMicajah Mindtouch Deki Wiki Copier: Small C# application to move data between 2 Deki Wiki installs or, more importantly, from a wik.is account to a locally installed systemMineFlagger: MineFlagger is a mine clearing game modeled after Microsoft’s Minesweeper. In addition to standard play, MineFlagger incorporates an AI for fun and training.myXbyqwrhjadsfasfhgf: myXbyqwrhjadsfasfhgfnatoop: natoopNauplius.KeyStore: Provides secure application key storage backed by SQL 2008 and Active Directory.ObjectDB: An object database written using C# 4 and Mono.Cecil.PaceR: PaceR is an attempt to encapsulate a lot of the common code functionality I use on different projects. Instead of recreating functionality from memory or worse, copying from older projects, I'd like to have a central location to maintain this common code. Parseq: Parseq is a Parser Combinator library written in C# (version 2.0).PowerShell Network Adapter Configuration module: PowerShell Network Adapter Configuration module is a PowerShell module which provides functions for managing network adapters using WMI.public traffic tracker: This is a university project for a .net course. We develop a public traffic tracker applications for Windows Phone 7 devices, that can give information about the actual positions of the nearest vehicle on a given line. The speciality is that we use only the GPS information of the users' WP7 devices, so this is a completely software solution without any hardware investment. The disatvantage is that for the real operation we would need a lot of active WP7 user.puyo: puyoRadioTroll: Projeto web Radio TrollRead Feed Community: Read Feed CommunityReviewer: Reviewer.dk - Dansk spil og anmeldelsessite.Rollout Sharepoint Solutions - ROSS: ROSS performs the following actions: - Delete sitecollection and restart services - 'Get Latest Version' from SourceSafe - Rebuild Solution - Install all wsp solutions - Create SiteCollections - Check for build en provisioning errors - Send email to developers if errors occurredSchool Management: school managementSQL File Executer: This project is a class library written in c# which is used for executing *.sql files in remote server. Simply one dll file. You include it in your web project, add using statement at the top of your page, pass the parameters inside. Rest, it will do.Startup Manager: Startup Manager launches all startup programs at a managed rate therefore meaning that your computer doesn't crash everytime it starts up and you can use it immediately.stetic: ...Test Infrastructure Guidance: The purpose of this project is to provide guidance to testers in using TFS effectively as an ALM solution. TFS is much more than a simple code repository. Used with Visual Studio it can form a powerful testing solution and remove a lot of pain in dealing with test infrastructure overhead.Tête-à-tête: Tete-a-tete is an address book with a built-in function to send electronic mail over the Internet.Tipeysh! - Add-in that helps you creating C/C++ header files on a single click: Are you also feel miserable when you need to create a new header file in your Visual Studio C/C++ project? Repeatedly choosing "new header file", then writing the annoying (but needed) "#ifndef" section, then writing the class name with it's "private", "protected" and "public" access modifiers... too much clicks and typewriting! Well, there is a solution: Tipeysh! is a simple, easy to use, very handy and configurable Visual Studio Add-In, compatible for both the 2005 and 2008 versions. Once ...UMN Dashboard Project: academic projUsersMOSS: UsersMOSS est une petite application permettant de consulter sur un serveur MOSS les sites web (SPWeb) les users (SPUser), et les groupes (SPGroup). Cette application utilise le modèle objet de MOSS pour inspecter le contenu des objets d'un serveur MOSS. Cette application est loin d'être professionnelle, ou même terminée, mais elle me rend très souvent service. Surtout ne l'utilisez pas sur un serveur de production car le gestion du GC n'est pas faite, ce qui peut provoquer des plantages de v...UtilityLibrary.Win32: UtilityLibrary.Win32UW iLearn: The iLearn activity inference platform is a suite of desktop and mobile tools for logging, modeling, and classifying sensor data for mobile devices. It was created at the University of Washington.VsDocGen: Dynamic javascript documentation generation directly from xml comment documented source code.Windows Live Spaces Photo Album plugin: This is going to be a plugin for Windows Live Writer that will allow you to browse a Windows Live Space Photo Album.Windows Live Writer Plugin for Amazon Books using CueCat: This Windows Live Writer Plugin is for users who use WLW and wish to use their CueCat to scan books. ItemLookups are run against Amazon via its AWS and book image, title, author, and publisher is returned. This project was first created by Scott Hanselman on MSDN's Coding4Fun! X7: X7 makes it easier for win7user to clean the system. You'll no longer have to delete useless stuff in your win7. It's developed in bat.xDT - Commander: Using this application, the user can assign shortcuts (short texts) for various links/URLs. These short texts will be typed into a Textbox to then launch/go to the target (similar to the "Run" program in Windows).

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• Informed TDD &ndash; Kata &ldquo;To Roman Numerals&rdquo;

  - by Ralf Westphal

  Originally posted on: http://geekswithblogs.net/theArchitectsNapkin/archive/2014/05/28/informed-tdd-ndash-kata-ldquoto-roman-numeralsrdquo.aspxIn a comment on my article on what I call Informed TDD (ITDD) reader gustav asked how this approach would apply to the kata “To Roman Numerals”. And whether ITDD wasn´t a violation of TDD´s principle of leaving out “advanced topics like mocks”. I like to respond with this article to his questions. There´s more to say than fits into a commentary. Mocks and TDD I don´t see in how far TDD is avoiding or opposed to mocks. TDD and mocks are orthogonal. TDD is about pocess, mocks are about structure and costs. Maybe by moving forward in tiny red+green+refactor steps less need arises for mocks. But then… if the functionality you need to implement requires “expensive” resource access you can´t avoid using mocks. Because you don´t want to constantly run all your tests against the real resource. True, in ITDD mocks seem to be in almost inflationary use. That´s not what you usually see in TDD demonstrations. However, there´s a reason for that as I tried to explain. I don´t use mocks as proxies for “expensive” resource. Rather they are stand-ins for functionality not yet implemented. They allow me to get a test green on a high level of abstraction. That way I can move forward in a top-down fashion. But if you think of mocks as “advanced” or if you don´t want to use a tool like JustMock, then you don´t need to use mocks. You just need to stand the sight of red tests for a little longer ;-) Let me show you what I mean by that by doing a kata. ITDD for “To Roman Numerals” gustav asked for the kata “To Roman Numerals”. I won´t explain the requirements again. You can find descriptions and TDD demonstrations all over the internet, like this one from Corey Haines. Now here is, how I would do this kata differently. 1. Analyse A demonstration of TDD should never skip the analysis phase. It should be made explicit. The requirements should be formalized and acceptance test cases should be compiled. “Formalization” in this case to me means describing the API of the required functionality. “[D]esign a program to work with Roman numerals” like written in this “requirement document” is not enough to start software development. Coding should only begin, if the interface between the “system under development” and its context is clear. If this interface is not readily recognizable from the requirements, it has to be developed first. Exploration of interface alternatives might be in order. It might be necessary to show several interface mock-ups to the customer – even if that´s you fellow developer. Designing the interface is a task of it´s own. It should not be mixed with implementing the required functionality behind the interface. Unfortunately, though, this happens quite often in TDD demonstrations. TDD is used to explore the API and implement it at the same time. To me that´s a violation of the Single Responsibility Principle (SRP) which not only should hold for software functional units but also for tasks or activities. In the case of this kata the API fortunately is obvious. Just one function is needed: string ToRoman(int arabic). And it lives in a class ArabicRomanConversions. Now what about acceptance test cases? There are hardly any stated in the kata descriptions. Roman numerals are explained, but no specific test cases from the point of view of a customer. So I just “invent” some acceptance test cases by picking roman numerals from a wikipedia article. They are supposed to be just “typical examples” without special meaning. Given the acceptance test cases I then try to develop an understanding of the problem domain. I´ll spare you that. The domain is trivial and is explain in almost all kata descriptions. How roman numerals are built is not difficult to understand. What´s more difficult, though, might be to find an efficient solution to convert into them automatically. 2. Solve The usual TDD demonstration skips a solution finding phase. Like the interface exploration it´s mixed in with the implementation. But I don´t think this is how it should be done. I even think this is not how it really works for the people demonstrating TDD. They´re simplifying their true software development process because they want to show a streamlined TDD process. I doubt this is helping anybody. Before you code you better have a plan what to code. This does not mean you have to do “Big Design Up-Front”. It just means: Have a clear picture of the logical solution in your head before you start to build a physical solution (code). Evidently such a solution can only be as good as your understanding of the problem. If that´s limited your solution will be limited, too. Fortunately, in the case of this kata your understanding does not need to be limited. Thus the logical solution does not need to be limited or preliminary or tentative. That does not mean you need to know every line of code in advance. It just means you know the rough structure of your implementation beforehand. Because it should mirror the process described by the logical or conceptual solution. Here´s my solution approach: The arabic “encoding” of numbers represents them as an ordered set of powers of 10. Each digit is a factor to multiply a power of ten with. The “encoding” 123 is the short form for a set like this: {1*10^2, 2*10^1, 3*10^0}. And the number is the sum of the set members. The roman “encoding” is different. There is no base (like 10 for arabic numbers), there are just digits of different value, and they have to be written in descending order. The “encoding” XVI is short for [10, 5, 1]. And the number is still the sum of the members of this list. The roman “encoding” thus is simpler than the arabic. Each “digit” can be taken at face value. No multiplication with a base required. But what about IV which looks like a contradiction to the above rule? It is not – if you accept roman “digits” not to be limited to be single characters only. Usually I, V, X, L, C, D, M are viewed as “digits”, and IV, IX etc. are viewed as nuisances preventing a simple solution. All looks different, though, once IV, IX etc. are taken as “digits”. Then MCMLIV is just a sum: M+CM+L+IV which is 1000+900+50+4. Whereas before it would have been understood as M-C+M+L-I+V – which is more difficult because here some “digits” get subtracted. Here´s the list of roman “digits” with their values: {1, I}, {4, IV}, {5, V}, {9, IX}, {10, X}, {40, XL}, {50, L}, {90, XC}, {100, C}, {400, CD}, {500, D}, {900, CM}, {1000, M} Since I take IV, IX etc. as “digits” translating an arabic number becomes trivial. I just need to find the values of the roman “digits” making up the number, e.g. 1954 is made up of 1000, 900, 50, and 4. I call those “digits” factors. If I move from the highest factor (M=1000) to the lowest (I=1) then translation is a two phase process: Find all the factors Translate the factors found Compile the roman representation Translation is just a look-up. Finding, though, needs some calculation: Find the highest remaining factor fitting in the value Remember and subtract it from the value Repeat with remaining value and remaining factors Please note: This is just an algorithm. It´s not code, even though it might be close. Being so close to code in my solution approach is due to the triviality of the problem. In more realistic examples the conceptual solution would be on a higher level of abstraction. With this solution in hand I finally can do what TDD advocates: find and prioritize test cases. As I can see from the small process description above, there are two aspects to test: Test the translation Test the compilation Test finding the factors Testing the translation primarily means to check if the map of factors and digits is comprehensive. That´s simple, even though it might be tedious. Testing the compilation is trivial. Testing factor finding, though, is a tad more complicated. I can think of several steps: First check, if an arabic number equal to a factor is processed correctly (e.g. 1000=M). Then check if an arabic number consisting of two consecutive factors (e.g. 1900=[M,CM]) is processed correctly. Then check, if a number consisting of the same factor twice is processed correctly (e.g. 2000=[M,M]). Finally check, if an arabic number consisting of non-consecutive factors (e.g. 1400=[M,CD]) is processed correctly. I feel I can start an implementation now. If something becomes more complicated than expected I can slow down and repeat this process. 3. Implement First I write a test for the acceptance test cases. It´s red because there´s no implementation even of the API. That´s in conformance with “TDD lore”, I´d say: Next I implement the API: The acceptance test now is formally correct, but still red of course. This will not change even now that I zoom in. Because my goal is not to most quickly satisfy these tests, but to implement my solution in a stepwise manner. That I do by “faking” it: I just “assume” three functions to represent the transformation process of my solution: My hypothesis is that those three functions in conjunction produce correct results on the API-level. I just have to implement them correctly. That´s what I´m trying now – one by one. I start with a simple “detail function”: Translate(). And I start with all the test cases in the obvious equivalence partition: As you can see I dare to test a private method. Yes. That´s a white box test. But as you´ll see it won´t make my tests brittle. It serves a purpose right here and now: it lets me focus on getting one aspect of my solution right. Here´s the implementation to satisfy the test: It´s as simple as possible. Right how TDD wants me to do it: KISS. Now for the second equivalence partition: translating multiple factors. (It´a pattern: if you need to do something repeatedly separate the tests for doing it once and doing it multiple times.) In this partition I just need a single test case, I guess. Stepping up from a single translation to multiple translations is no rocket science: Usually I would have implemented the final code right away. Splitting it in two steps is just for “educational purposes” here. How small your implementation steps are is a matter of your programming competency. Some “see” the final code right away before their mental eye – others need to work their way towards it. Having two tests I find more important. Now for the next low hanging fruit: compilation. It´s even simpler than translation. A single test is enough, I guess. And normally I would not even have bothered to write that one, because the implementation is so simple. I don´t need to test .NET framework functionality. But again: if it serves the educational purpose… Finally the most complicated part of the solution: finding the factors. There are several equivalence partitions. But still I decide to write just a single test, since the structure of the test data is the same for all partitions: Again, I´m faking the implementation first: I focus on just the first test case. No looping yet. Faking lets me stay on a high level of abstraction. I can write down the implementation of the solution without bothering myself with details of how to actually accomplish the feat. That´s left for a drill down with a test of the fake function: There are two main equivalence partitions, I guess: either the first factor is appropriate or some next. The implementation seems easy. Both test cases are green. (Of course this only works on the premise that there´s always a matching factor. Which is the case since the smallest factor is 1.) And the first of the equivalence partitions on the higher level also is satisfied: Great, I can move on. Now for more than a single factor: Interestingly not just one test becomes green now, but all of them. Great! You might say, then I must have done not the simplest thing possible. And I would reply: I don´t care. I did the most obvious thing. But I also find this loop very simple. Even simpler than a recursion of which I had thought briefly during the problem solving phase. And by the way: Also the acceptance tests went green: Mission accomplished. At least functionality wise. Now I´ve to tidy up things a bit. TDD calls for refactoring. Not uch refactoring is needed, because I wrote the code in top-down fashion. I faked it until I made it. I endured red tests on higher levels while lower levels weren´t perfected yet. But this way I saved myself from refactoring tediousness. At the end, though, some refactoring is required. But maybe in a different way than you would expect. That´s why I rather call it “cleanup”. First I remove duplication. There are two places where factors are defined: in Translate() and in Find_factors(). So I factor the map out into a class constant. Which leads to a small conversion in Find_factors(): And now for the big cleanup: I remove all tests of private methods. They are scaffolding tests to me. They only have temporary value. They are brittle. Only acceptance tests need to remain. However, I carry over the single “digit” tests from Translate() to the acceptance test. I find them valuable to keep, since the other acceptance tests only exercise a subset of all roman “digits”. This then is my final test class: And this is the final production code: Test coverage as reported by NCrunch is 100%: Reflexion Is this the smallest possible code base for this kata? Sure not. You´ll find more concise solutions on the internet. But LOC are of relatively little concern – as long as I can understand the code quickly. So called “elegant” code, however, often is not easy to understand. The same goes for KISS code – especially if left unrefactored, as it is often the case. That´s why I progressed from requirements to final code the way I did. I first understood and solved the problem on a conceptual level. Then I implemented it top down according to my design. I also could have implemented it bottom-up, since I knew some bottom of the solution. That´s the leaves of the functional decomposition tree. Where things became fuzzy, since the design did not cover any more details as with Find_factors(), I repeated the process in the small, so to speak: fake some top level, endure red high level tests, while first solving a simpler problem. Using scaffolding tests (to be thrown away at the end) brought two advantages: Encapsulation of the implementation details was not compromised. Naturally private methods could stay private. I did not need to make them internal or public just to be able to test them. I was able to write focused tests for small aspects of the solution. No need to test everything through the solution root, the API. The bottom line thus for me is: Informed TDD produces cleaner code in a systematic way. It conforms to core principles of programming: Single Responsibility Principle and/or Separation of Concerns. Distinct roles in development – being a researcher, being an engineer, being a craftsman – are represented as different phases. First find what, what there is. Then devise a solution. Then code the solution, manifest the solution in code. Writing tests first is a good practice. But it should not be taken dogmatic. And above all it should not be overloaded with purposes. And finally: moving from top to bottom through a design produces refactored code right away. Clean code thus almost is inevitable – and not left to a refactoring step at the end which is skipped often for different reasons.   PS: Yes, I have done this kata several times. But that has only an impact on the time needed for phases 1 and 2. I won´t skip them because of that. And there are no shortcuts during implementation because of that.

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• ZFS for Database Log Files

  - by user12620111

  I've been troubled by drop outs in CPU usage in my application server, characterized by the CPUs suddenly going from close to 90% CPU busy to almost completely CPU idle for a few seconds. Here is an example of a drop out as shown by a snippet of vmstat data taken while the application server is under a heavy workload. # vmstat 1  kthr      memory            page            disk          faults      cpu  r b w   swap  free  re  mf pi po fr de sr s3 s4 s5 s6   in   sy   cs us sy id  1 0 0 130160176 116381952 0 16 0 0 0 0  0  0  0  0  0 207377 117715 203884 70 21 9  12 0 0 130160160 116381936 0 25 0 0 0 0 0  0  0  0  0 200413 117162 197250 70 20 9  11 0 0 130160176 116381920 0 16 0 0 0 0 0  0  1  0  0 203150 119365 200249 72 21 7  8 0 0 130160176 116377808 0 19 0 0 0 0  0  0  0  0  0 169826 96144 165194 56 17 27  0 0 0 130160176 116377800 0 16 0 0 0 0  0  0  0  0  1 10245 9376 9164 2  1 97  0 0 0 130160176 116377792 0 16 0 0 0 0  0  0  0  0  2 15742 12401 14784 4 1 95  0 0 0 130160176 116377776 2 16 0 0 0 0  0  0  1  0  0 19972 17703 19612 6 2 92  14 0 0 130160176 116377696 0 16 0 0 0 0 0  0  0  0  0 202794 116793 199807 71 21 8  9 0 0 130160160 116373584 0 30 0 0 0 0  0  0 18  0  0 203123 117857 198825 69 20 11 This behavior occurred consistently while the application server was processing synthetic transactions: HTTP requests from JMeter running on an external machine. I explored many theories trying to explain the drop outs, including: Unexpected JMeter behavior Network contention Java Garbage Collection Application Server thread pool problems Connection pool problems Database transaction processing Database I/O contention Graphing the CPU %idle led to a breakthrough: Several of the drop outs were 30 seconds apart. With that insight, I went digging through the data again and looking for other outliers that were 30 seconds apart. In the database server statistics, I found spikes in the iostat "asvc_t" (average response time of disk transactions, in milliseconds) for the disk drive that was being used for the database log files. Here is an example:                     extended device statistics     r/s    w/s   kr/s   kw/s wait actv wsvc_t asvc_t  %w  %b device     0.0 2053.6    0.0 8234.3  0.0  0.2    0.0    0.1   0  24 c3t60080E5...F4F6d0s0     0.0 2162.2    0.0 8652.8  0.0  0.3    0.0    0.1   0  28 c3t60080E5...F4F6d0s0     0.0 1102.5    0.0 10012.8  0.0  4.5    0.0    4.1   0  69 c3t60080E5...F4F6d0s0     0.0   74.0    0.0 7920.6  0.0 10.0    0.0  135.1   0 100 c3t60080E5...F4F6d0s0     0.0  568.7    0.0 6674.0  0.0  6.4    0.0   11.2   0  90 c3t60080E5...F4F6d0s0     0.0 1358.0    0.0 5456.0  0.0  0.6    0.0    0.4   0  55 c3t60080E5...F4F6d0s0     0.0 1314.3    0.0 5285.2  0.0  0.7    0.0    0.5   0  70 c3t60080E5...F4F6d0s0 Here is a little more information about my database configuration: The database and application server were running on two different SPARC servers. Storage for the database was on a storage array connected via 8 gigabit Fibre Channel Data storage and log file were on different physical disk drives Reliable low latency I/O is provided by battery backed NVRAM Highly available: Two Fibre Channel links accessed via MPxIO Two Mirrored cache controllers The log file physical disks were mirrored in the storage device Database log files on a ZFS Filesystem with cutting-edge technologies, such as copy-on-write and end-to-end checksumming Why would I be getting service time spikes in my high-end storage? First, I wanted to verify that the database log disk service time spikes aligned with the application server CPU drop outs, and they did: At first, I guessed that the disk service time spikes might be related to flushing the write through cache on the storage device, but I was unable to validate that theory. After searching the WWW for a while, I decided to try using a separate log device: # zpool add ZFS-db-41 log c3t60080E500017D55C000015C150A9F8A7d0 The ZFS log device is configured in a similar manner as described above: two physical disks mirrored in the storage array. This change to the database storage configuration eliminated the application server CPU drop outs: Here is the zpool configuration: # zpool status ZFS-db-41   pool: ZFS-db-41  state: ONLINE  scan: none requested config:         NAME                                     STATE         ZFS-db-41                                ONLINE           c3t60080E5...F4F6d0  ONLINE         logs           c3t60080E5...F8A7d0  ONLINE Now, the I/O spikes look like this:                     extended device statistics                  r/s    w/s   kr/s   kw/s wait actv wsvc_t asvc_t  %w  %b device     0.0 1053.5    0.0 4234.1  0.0  0.8    0.0    0.7   0  75 c3t60080E5...F8A7d0s0                     extended device statistics                  r/s    w/s   kr/s   kw/s wait actv wsvc_t asvc_t  %w  %b device     0.0 1131.8    0.0 4555.3  0.0  0.8    0.0    0.7   0  76 c3t60080E5...F8A7d0s0                     extended device statistics                  r/s    w/s   kr/s   kw/s wait actv wsvc_t asvc_t  %w  %b device     0.0 1167.6    0.0 4682.2  0.0  0.7    0.0    0.6   0  74 c3t60080E5...F8A7d0s0     0.0  162.2    0.0 19153.9  0.0  0.7    0.0    4.2   0  12 c3t60080E5...F4F6d0s0                     extended device statistics                  r/s    w/s   kr/s   kw/s wait actv wsvc_t asvc_t  %w  %b device     0.0 1247.2    0.0 4992.6  0.0  0.7    0.0    0.6   0  71 c3t60080E5...F8A7d0s0     0.0   41.0    0.0   70.0  0.0  0.1    0.0    1.6   0   2 c3t60080E5...F4F6d0s0                     extended device statistics                  r/s    w/s   kr/s   kw/s wait actv wsvc_t asvc_t  %w  %b device     0.0 1241.3    0.0 4989.3  0.0  0.8    0.0    0.6   0  75 c3t60080E5...F8A7d0s0                     extended device statistics                  r/s    w/s   kr/s   kw/s wait actv wsvc_t asvc_t  %w  %b device     0.0 1193.2    0.0 4772.9  0.0  0.7    0.0    0.6   0  71 c3t60080E5...F8A7d0s0 We can see the steady flow of 4k writes to the ZIL device from O_SYNC database log file writes. The spikes are from flushing the transaction group. Like almost all problems that I run into, once I thoroughly understand the problem, I find that other people have documented similar experiences. Thanks to all of you who have documented alternative approaches. Saved for another day: now that the problem is obvious, I should try "zfs:zfs_immediate_write_sz" as recommended in the ZFS Evil Tuning Guide. References: The ZFS Intent Log Solaris ZFS, Synchronous Writes and the ZIL Explained ZFS Evil Tuning Guide: Cache Flushes ZFS Evil Tuning Guide: Tuning ZFS for Database Performance

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• Why is iTunes starting and stopping play randomly, and how do I stop it?

  - by Chris R

  Since yesterday morning my copy of iTunes has been starting and stopping randomly. If iTunes is not running, then it opens and sometimes begins playing, other times sits idle. Eventually, after a random interval it will begin playing a song, and then stop, and so on... Needless to say, it's driving me mad. (Mac OSX, 10.6.3, on a new-ish (< 1 year old) 24" iMac) I've made five changes to my system that may or may not be connected to this: My office phone was replaced with a Linksys IP Phone, which necessitated a change to my networking; where previously my Mac was connected directly to the office network port, now it is connected through the phone. My network connection now uses auto link detection in lieu of forcing 100Mbit I unpaired my bluetooth headset. I removed the USB audio device associated with another headset. I upgraded to Safari 5. I don't use it as a primary browser, but it's often open to run web apps that I'm developing. All of these things happened in pretty close proximity to each other, so one or more of them may be the culprit. One other thing that may or may not be related; for some reason my built-in microphone is no longer picking up audio. It seems like this might be connected to the iTunes issue, because it happened around the same time. In terms of things that I've tried in order to solve this, I'm at a bit of a loss. I followed the instructions at http://developer.apple.com/mac/library/technotes/tn2004/tn2124.html#SECLAUNCHDLOGGING to enable detailed launchd logging to see if I could track down which process was asking iTunes to open (when it's not already open) but I wasn't able to make heads or tails of the output. I'm not even sure if I'm looking in the right place, to be honest; it actually acts like something is activating the application with AppleScript, but I have no processes running that are doing that, as far as I know. I'm running a few apps that have iTunes integration: Adium, iChat with Chax, Quicksilver. None of these have been changed lately, so I consider them low risks of causing this, but it's not impossible. Moreover, I'm not using any of those features intentionally. This is a snippet of launchd debug logging from around the time it just launched: 10-06-09 9:14:29 AM com.apple.launchd[1] Dispatching kevent... 10-06-09 9:14:29 AM com.apple.launchd[1] KEVENT[0]: udata = 0x10002b230 data = 0x30 ident = 5 filter = EVFILT_READ flags = EV_ADD|EV_RECEIPT fflags = 0x0 10-06-09 9:14:29 AM com.apple.launchd[1] Dispatching kevent... 10-06-09 9:14:29 AM com.apple.launchd[1] KEVENT[0]: udata = 0x100802000 data = 0x0 ident = 26 filter = EVFILT_PROC flags = EV_ADD|EV_RECEIPT|EV_CLEAR fflags = NOTE_FORK 10-06-09 9:14:29 AM com.apple.launchd[1] (com.apple.coreservicesd[26]) Dispatching kevent callback. 10-06-09 9:14:29 AM com.apple.launchd[1] (com.apple.coreservicesd[26]) EVFILT_PROC event for job: 10-06-09 9:14:29 AM com.apple.launchd[1] KEVENT[0]: udata = 0x1004076f0 data = 0x0 ident = 26 filter = EVFILT_PROC flags = EV_ADD|EV_RECEIPT|EV_CLEAR fflags = NOTE_FORK 10-06-09 9:14:29 AM com.apple.launchd[1] (com.apple.coreservicesd[26]) fork()ed 10-06-09 9:14:29 AM com.apple.launchd[1] (0x100401720.anonymous.lssave) Conceived 10-06-09 9:14:29 AM com.apple.launchd[1] (0x100401720.anonymous.lssave[22197]) Created PID 22197 anonymously by PPID 26 10-06-09 9:14:29 AM com.apple.launchd[1] (0x100401720.anonymous.lssave[22197]) Looking up per user launchd for UID: 0 10-06-09 9:14:29 AM com.apple.launchd[1] (0x100401720.anonymous.lssave[22197]) Per user launchd job found for UID: 505 10-06-09 9:14:29 AM com.apple.launchd[1] System: Looking up service com.apple.system.notification_center 10-06-09 9:14:29 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.system.notification_center 10-06-09 9:14:29 AM com.apple.launchd[1] (0x100401720.anonymous.lssave[22197]) Looking up per user launchd for UID: 0 10-06-09 9:14:29 AM com.apple.launchd[1] (0x100401720.anonymous.lssave[22197]) Per user launchd job found for UID: 505 10-06-09 9:14:29 AM com.apple.launchd[1] System: Looking up service com.apple.system.DirectoryService.libinfo_v1 10-06-09 9:14:29 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.system.DirectoryService.libinfo_v1 10-06-09 9:14:29 AM com.apple.launchd[1] (0x100401720.anonymous.lssave[22197]) Looking up per user launchd for UID: 0 10-06-09 9:14:29 AM com.apple.launchd[1] (0x100401720.anonymous.lssave[22197]) Per user launchd job found for UID: 505 10-06-09 9:14:29 AM com.apple.launchd[1] System: Looking up service com.apple.system.DirectoryService.membership_v1 10-06-09 9:14:29 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.system.DirectoryService.membership_v1 10-06-09 9:14:29 AM com.apple.launchd[1] (0x100401720.anonymous.lssave[22197]) Looking up per user launchd for UID: 0 10-06-09 9:14:29 AM com.apple.launchd[1] (0x100401720.anonymous.lssave[22197]) Per user launchd job found for UID: 505 10-06-09 9:14:29 AM com.apple.launchd[1] System: Looking up service com.apple.CoreServices.coreservicesd 10-06-09 9:14:29 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.CoreServices.coreservicesd 10-06-09 9:14:29 AM com.apple.launchd[1] Dispatching kevent... 10-06-09 9:14:29 AM com.apple.launchd[1] KEVENT[0]: udata = 0x100802000 data = 0x0 ident = 22197 filter = EVFILT_PROC flags = EV_ADD|EV_RECEIPT|EV_CLEAR fflags = NOTE_EXIT 10-06-09 9:14:29 AM com.apple.launchd[1] (0x100401720.anonymous.lssave[22197]) Dispatching kevent callback. 10-06-09 9:14:29 AM com.apple.launchd[1] (0x100401720.anonymous.lssave[22197]) EVFILT_PROC event for job: 10-06-09 9:14:29 AM com.apple.launchd[1] KEVENT[0]: udata = 0x100401720 data = 0x0 ident = 22197 filter = EVFILT_PROC flags = EV_ADD|EV_RECEIPT|EV_CLEAR fflags = NOTE_EXIT 10-06-09 9:14:29 AM com.apple.launchd[1] (0x100401720.anonymous.lssave[22197]) Reaping 10-06-09 9:14:29 AM com.apple.launchd[1] (0x100401720.anonymous.lssave) Total rusage: utime 0.000000 stime 0.000000 maxrss 0 ixrss 0 idrss 0 isrss 0 minflt 0 majflt 0 nswap 0 inblock 0 oublock 0 msgsnd 0 msgrcv 0 nsignals 0 nvcsw 0 nivcsw 0 10-06-09 9:14:29 AM com.apple.launchd[1] (0x100401720.anonymous.lssave) Removed 10-06-09 9:14:30 AM com.apple.launchd[1] Dispatching kevent... 10-06-09 9:14:30 AM com.apple.launchd[1] KEVENT[0]: udata = 0x100802000 data = 0x0 ident = 22197 filter = EVFILT_PROC flags = EV_ADD|EV_RECEIPT|EV_CLEAR|EV_EOF|EV_ONESHOT fflags = NOTE_REAP 10-06-09 9:14:32 AM com.apple.launchd[1] Dispatching kevent... 10-06-09 9:14:32 AM com.apple.launchd[1] KEVENT[0]: udata = 0x10002b230 data = 0x30 ident = 5 filter = EVFILT_READ flags = EV_ADD|EV_RECEIPT fflags = 0x0 10-06-09 9:14:33 AM com.apple.launchd[1] Dispatching kevent... 10-06-09 9:14:33 AM com.apple.launchd[1] KEVENT[0]: udata = 0x100802000 data = 0x0 ident = 143 filter = EVFILT_PROC flags = EV_ADD|EV_RECEIPT|EV_CLEAR fflags = NOTE_FORK 10-06-09 9:14:33 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) Dispatching kevent callback. 10-06-09 9:14:33 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) EVFILT_PROC event for job: 10-06-09 9:14:33 AM com.apple.launchd[1] KEVENT[0]: udata = 0x10041e9a0 data = 0x0 ident = 143 filter = EVFILT_PROC flags = EV_ADD|EV_RECEIPT|EV_CLEAR fflags = NOTE_FORK 10-06-09 9:14:33 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) fork()ed 10-06-09 9:14:33 AM com.apple.launchd[1] System: Looking up service com.apple.distributed_notifications.2 10-06-09 9:14:33 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.distributed_notifications.2 10-06-09 9:14:33 AM com.apple.launchd[1] System: Looking up service com.apple.system.notification_center 10-06-09 9:14:33 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.system.notification_center 10-06-09 9:14:33 AM com.apple.launchd[1] System: Looking up service com.apple.system.DirectoryService.libinfo_v1 10-06-09 9:14:33 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.system.DirectoryService.libinfo_v1 10-06-09 9:14:33 AM com.apple.launchd[1] System: Looking up service com.apple.system.DirectoryService.membership_v1 10-06-09 9:14:33 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.system.DirectoryService.membership_v1 10-06-09 9:14:33 AM com.apple.launchd[1] System: Looking up service com.apple.CoreServices.coreservicesd 10-06-09 9:14:33 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.CoreServices.coreservicesd 10-06-09 9:14:33 AM com.apple.launchd[1] System: Looking up service com.apple.SystemConfiguration.configd 10-06-09 9:14:33 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.SystemConfiguration.configd 10-06-09 9:14:33 AM com.apple.launchd[1] System: Looking up service com.apple.audio.coreaudiod 10-06-09 9:14:33 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.audio.coreaudiod 10-06-09 9:14:34 AM com.apple.launchd[1] System: Looking up service com.apple.system.logger 10-06-09 9:14:34 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.system.logger 10-06-09 9:14:35 AM com.apple.launchd[1] Dispatching kevent... 10-06-09 9:14:35 AM com.apple.launchd[1] KEVENT[0]: udata = 0x10002b230 data = 0x30 ident = 5 filter = EVFILT_READ flags = EV_ADD|EV_RECEIPT fflags = 0x0 10-06-09 9:14:35 AM com.apple.launchd[1] System: Looking up service com.apple.DiskArbitration.diskarbitrationd 10-06-09 9:14:35 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.DiskArbitration.diskarbitrationd 10-06-09 9:14:35 AM com.apple.launchd[1] System: Looking up service com.apple.system.logger 10-06-09 9:14:35 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.system.logger 10-06-09 9:14:36 AM com.apple.launchd[1] System: Looking up service com.apple.FSEvents 10-06-09 9:14:36 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.FSEvents 10-06-09 9:14:36 AM com.apple.launchd[1] System: Looking up service com.apple.SystemConfiguration.configd 10-06-09 9:14:36 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.SystemConfiguration.configd 10-06-09 9:14:38 AM com.apple.launchd[1] Dispatching kevent... 10-06-09 9:14:38 AM com.apple.launchd[1] KEVENT[0]: udata = 0x10002b230 data = 0x30 ident = 5 filter = EVFILT_READ flags = EV_ADD|EV_RECEIPT fflags = 0x0 10-06-09 9:14:39 AM com.apple.launchd[1] Dispatching kevent... 10-06-09 9:14:39 AM com.apple.launchd[1] KEVENT[0]: udata = 0x100802000 data = 0x0 ident = 26 filter = EVFILT_PROC flags = EV_ADD|EV_RECEIPT|EV_CLEAR fflags = NOTE_FORK 10-06-09 9:14:39 AM com.apple.launchd[1] (com.apple.coreservicesd[26]) Dispatching kevent callback. 10-06-09 9:14:39 AM com.apple.launchd[1] (com.apple.coreservicesd[26]) EVFILT_PROC event for job: 10-06-09 9:14:39 AM com.apple.launchd[1] KEVENT[0]: udata = 0x1004076f0 data = 0x0 ident = 26 filter = EVFILT_PROC flags = EV_ADD|EV_RECEIPT|EV_CLEAR fflags = NOTE_FORK 10-06-09 9:14:39 AM com.apple.launchd[1] (com.apple.coreservicesd[26]) fork()ed 10-06-09 9:14:39 AM com.apple.launchd[1] (0x100401720.anonymous.lssave) Conceived 10-06-09 9:14:39 AM com.apple.launchd[1] (0x100401720.anonymous.lssave[22211]) Created PID 22211 anonymously by PPID 26 10-06-09 9:14:39 AM com.apple.launchd[1] (0x100401720.anonymous.lssave[22211]) Looking up per user launchd for UID: 0 10-06-09 9:14:39 AM com.apple.launchd[1] (0x100401720.anonymous.lssave[22211]) Per user launchd job found for UID: 505 10-06-09 9:14:39 AM com.apple.launchd[1] System: Looking up service com.apple.system.notification_center 10-06-09 9:14:39 AM com.apple.launchd[1] (com.apple.launchd.peruser.505[143]) Mach service lookup: com.apple.system.notification_center 10-06-09 9:14:39 AM com.apple.launchd[1] (0x100401720.anonymous.lssave[22211]) Looking up per user launchd for UID: 0 10-06-09 9:14:39 AM com.apple.launchd[1] (0x100401720.anonymous.lssave[22211]) Per user launchd job found for UID: 505 10-06-09 9:14:39 AM com.apple.launchd[1] System: Looking up service com.apple.system.DirectoryService.libinfo_v1

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• FreeBSD performance tuning. Sysctls, loader.conf, kernel.

  - by SaveTheRbtz

  I wanted to share knowledge of tuning FreeBSD via sysctls, so i'm posting them with comments. Based on Igor Sysoev (author of nginx) presentation about FreeBSD tuning up to 100,000-200,000 active connections. Sysctls are for 7.x FreeBSD. Since 7.2 amd64 some of them are tuned well by default. Prior 7.0 some of them are boot only (set via /boot/loader.conf) or does not exist at all. Highload web server sysctls: # Max. backlog size kern.ipc.somaxconn=4096 # Shared memory // 7.2+ can use shared memory > 2Gb kern.ipc.shmmax=2147483648 # Sockets kern.ipc.maxsockets=204800 # Do not use lager sockbufs on 8.0 # ( http://old.nabble.com/Significant-performance-regression-for-increased-maxsockbuf-on-8.0-RELEASE-tt26745981.html#a26745981 ) kern.ipc.maxsockbuf=262144 # Recive clusters (on amd64 7.2+ 65k is default) # For such high value vm.kmem_size must be increased to 3G #kern.ipc.nmbclusters=229376 # Jumbo pagesize(4k/8k) clusters # Used as general packet storage for jumbo frames # can be monitored via `netstat -m` #kern.ipc.nmbjumbop=192000 # Jumbo 9k/16k clusters # If you are using them #kern.ipc.nmbjumbo9=24000 #kern.ipc.nmbjumbo16=10240 # Every socket is a file, so increase them kern.maxfiles=204800 kern.maxfilesperproc=200000 kern.maxvnodes=200000 # Turn off receive autotuning #net.inet.tcp.recvbuf_auto=0 # Small receive space, only usable on http-server, on file server this # should be increased to 65535 or even more #net.inet.tcp.recvspace=8192 # Small send space is useful for http servers that serve small files # Autotuned since 7.x net.inet.tcp.sendspace=16384 # This should be enabled if you going to use big spaces (>64k) #net.inet.tcp.rfc1323=1 # Turn this off on highspeed, lossless connections (LAN 1Gbit+) #net.inet.tcp.delayed_ack=0 # This feature is useful if you are serving data over modems, Gigabit Ethernet, # or even high speed WAN links (or any other link with a high bandwidth delay product), # especially if you are also using window scaling or have configured a large send window. # You can try setting it to 0 on fileserver with 1GBit+ interfaces # Automatically disables on small RTT ( http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/netinet/tcp_subr.c?#rev1.237 ) #net.inet.tcp.inflight.enable=0 # Disable randomizing of ports to avoid false RST # Before usage check SA here www.bsdcan.org/2006/papers/ImprovingTCPIP.pdf # (it's also says that port randomization auto-disables at some conn.rates, but I didn't tested it thou) #net.inet.ip.portrange.randomized=0 # Increase portrange # For outgoing connections only. Good for seed-boxes and ftp servers. net.inet.ip.portrange.first=1024 net.inet.ip.portrange.last=65535 # Security net.inet.ip.redirect=0 net.inet.ip.sourceroute=0 net.inet.ip.accept_sourceroute=0 net.inet.icmp.maskrepl=0 net.inet.icmp.log_redirect=0 net.inet.icmp.drop_redirect=1 net.inet.tcp.drop_synfin=1 # Security net.inet.udp.blackhole=1 net.inet.tcp.blackhole=2 # Increases default TTL, sometimes useful # Default is 64 net.inet.ip.ttl=128 # Lessen max segment life to conserve resources # ACK waiting time in miliseconds (default: 30000 from RFC) net.inet.tcp.msl=5000 # Max bumber of timewait sockets net.inet.tcp.maxtcptw=40960 # Don't use tw on local connections # As of 15 Apr 2009. Igor Sysoev says that nolocaltimewait has some buggy realization. # So disable it or now till get fixed #net.inet.tcp.nolocaltimewait=1 # FIN_WAIT_2 state fast recycle net.inet.tcp.fast_finwait2_recycle=1 # Time before tcp keepalive probe is sent # default is 2 hours (7200000) #net.inet.tcp.keepidle=60000 # Should be increased until net.inet.ip.intr_queue_drops is zero net.inet.ip.intr_queue_maxlen=4096 # Interrupt handling via multiple CPU, but with context switch. # You can play with it. Default is 1; #net.isr.direct=0 # This is for routers only #net.inet.ip.forwarding=1 #net.inet.ip.fastforwarding=1 # This speed ups dummynet when channel isn't saturated net.inet.ip.dummynet.io_fast=1 # Increase dummynet(4) hash #net.inet.ip.dummynet.hash_size=2048 #net.inet.ip.dummynet.max_chain_len # Should be increased when you have A LOT of files on server # (Increase until vfs.ufs.dirhash_mem becames lower) vfs.ufs.dirhash_maxmem=67108864 # Explicit Congestion Notification (see http://en.wikipedia.org/wiki/Explicit_Congestion_Notification) net.inet.tcp.ecn.enable=1 # Flowtable - flow caching mechanism # Useful for routers #net.inet.flowtable.enable=1 #net.inet.flowtable.nmbflows=65535 # Extreme polling tuning #kern.polling.burst_max=1000 #kern.polling.each_burst=1000 #kern.polling.reg_frac=100 #kern.polling.user_frac=1 #kern.polling.idle_poll=0 # IPFW dynamic rules and timeouts tuning # Increase dyn_buckets till net.inet.ip.fw.curr_dyn_buckets is lower net.inet.ip.fw.dyn_buckets=65536 net.inet.ip.fw.dyn_max=65536 net.inet.ip.fw.dyn_ack_lifetime=120 net.inet.ip.fw.dyn_syn_lifetime=10 net.inet.ip.fw.dyn_fin_lifetime=2 net.inet.ip.fw.dyn_short_lifetime=10 # Make packets pass firewall only once when using dummynet # i.e. packets going thru pipe are passing out from firewall with accept #net.inet.ip.fw.one_pass=1 # shm_use_phys Wires all shared pages, making them unswappable # Use this to lessen Virtual Memory Manager's work when using Shared Mem. # Useful for databases #kern.ipc.shm_use_phys=1 /boot/loader.conf: # Accept filters for data, http and DNS requests # Usefull when your software uses select() instead of kevent/kqueue or when you under DDoS # DNS accf available on 8.0+ accf_data_load="YES" accf_http_load="YES" accf_dns_load="YES" # Async IO system calls aio_load="YES" # Adds NCQ support in FreeBSD # WARNING! all ad[0-9]+ devices will be renamed to ada[0-9]+ # 8.0+ only #ahci_load= #siis_load= # Increase kernel memory size to 3G. # # Use ONLY if you have KVA_PAGES in kernel configuration, and you have more than 3G RAM # Otherwise panic will happen on next reboot! # # It's required for high buffer sizes: kern.ipc.nmbjumbop, kern.ipc.nmbclusters, etc # Useful on highload stateful firewalls, proxies or ZFS fileservers # (FreeBSD 7.2+ amd64 users: Check that current value is lower!) #vm.kmem_size="3G" # Older versions of FreeBSD can't tune maxfiles on the fly #kern.maxfiles="200000" # Useful for databases # Sets maximum data size to 1G # (FreeBSD 7.2+ amd64 users: Check that current value is lower!) #kern.maxdsiz="1G" # Maximum buffer size(vfs.maxbufspace) # You can check current one via vfs.bufspace # Should be lowered/upped depending on server's load-type # Usually decreased to preserve kmem # (default is 200M) #kern.maxbcache="512M" # Sendfile buffers # For i386 only #kern.ipc.nsfbufs=10240 # syncache Hash table tuning net.inet.tcp.syncache.hashsize=1024 net.inet.tcp.syncache.bucketlimit=100 # Incresed hostcache net.inet.tcp.hostcache.hashsize="16384" net.inet.tcp.hostcache.bucketlimit="100" # TCP control-block Hash table tuning net.inet.tcp.tcbhashsize=4096 # Enable superpages, for 7.2+ only # Also read http://lists.freebsd.org/pipermail/freebsd-hackers/2009-November/030094.html vm.pmap.pg_ps_enabled=1 # Usefull if you are using Intel-Gigabit NIC #hw.em.rxd=4096 #hw.em.txd=4096 #hw.em.rx_process_limit="-1" # Also if you have ALOT interrupts on NIC - play with following parameters # NOTE: You should set them for every NIC #dev.em.0.rx_int_delay: 250 #dev.em.0.tx_int_delay: 250 #dev.em.0.rx_abs_int_delay: 250 #dev.em.0.tx_abs_int_delay: 250 # There is also multithreaded version of em drivers can be found here: # http://people.yandex-team.ru/~wawa/ # # for additional em monitoring and statistics use # `sysctl dev.em.0.stats=1 ; dmesg` # #Same tunings for igb #hw.igb.rxd=4096 #hw.igb.txd=4096 #hw.igb.rx_process_limit=100 # Some useful netisr tunables. See sysctl net.isr #net.isr.defaultqlimit=4096 #net.isr.maxqlimit: 10240 # Bind netisr threads to CPUs #net.isr.bindthreads=1 # Nicer boot logo =) loader_logo="beastie" And finally here is my additions to GENERIC kernel # Just some of them, see also # cat /sys/{i386,amd64,}/conf/NOTES # This one useful only on i386 #options KVA_PAGES=512 # You can play with HZ in environments with high interrupt rate (default is 1000) # 100 is for my notebook to prolong it's battery life #options HZ=100 # Polling is goot on network loads with high packet rates and low-end NICs # NB! Do not enable it if you want more than one netisr thread #options DEVICE_POLLING # Eliminate datacopy on socket read-write # To take advantage with zero copy sockets you should have an MTU of 8K(amd64) # (4k for i386). This req. is only for receiving data. # Read more in man zero_copy_sockets #options ZERO_COPY_SOCKETS # Support TCP sign. Used for IPSec options TCP_SIGNATURE options IPSEC # This ones can be loaded as modules. They described in loader.conf section #options ACCEPT_FILTER_DATA #options ACCEPT_FILTER_HTTP # Adding ipfw, also can be loaded as modules options IPFIREWALL options IPFIREWALL_VERBOSE options IPFIREWALL_VERBOSE_LIMIT=10 options IPFIREWALL_DEFAULT_TO_ACCEPT options IPFIREWALL_FORWARD # Adding kernel NAT options IPFIREWALL_NAT options LIBALIAS # Traffic shaping options DUMMYNET # Divert, i.e. for userspace NAT options IPDIVERT # This is for OpenBSD's pf firewall device pf device pflog # pf's QoS - ALTQ options ALTQ options ALTQ_CBQ # Class Bases Queuing (CBQ) options ALTQ_RED # Random Early Detection (RED) options ALTQ_RIO # RED In/Out options ALTQ_HFSC # Hierarchical Packet Scheduler (HFSC) options ALTQ_PRIQ # Priority Queuing (PRIQ) options ALTQ_NOPCC # Required for SMP build # Pretty console # Manual can be found here http://forums.freebsd.org/showthread.php?t=6134 #options VESA #options SC_PIXEL_MODE # Disable reboot on Ctrl Alt Del #options SC_DISABLE_REBOOT # Change normal|kernel messages color options SC_NORM_ATTR=(FG_GREEN|BG_BLACK) options SC_KERNEL_CONS_ATTR=(FG_YELLOW|BG_BLACK) # More scroll space options SC_HISTORY_SIZE=8192 # Adding hardware crypto device device crypto device cryptodev # Useful network interfaces device vlan device tap #Virtual Ethernet driver device gre #IP over IP tunneling device if_bridge #Bridge interface device pfsync #synchronization interface for PF device carp #Common Address Redundancy Protocol device enc #IPsec interface device lagg #Link aggregation interface device stf #IPv4-IPv6 port # Also for my notebook, but may be used with Opteron #device amdtemp # Support for ECMP. More than one route for destination # Works even with default route so one can use it as LB for two ISP # For now code is unstable and panics (panic: rtfree 2) on route deletions. #options RADIX_MPATH # Multicast routing #options MROUTING #options PIM # DTrace options KDTRACE_HOOKS # all architectures - enable general DTrace hooks options DDB_CTF # all architectures - kernel ELF linker loads CTF data #options KDTRACE_FRAME # amd64-only # Adaptive spining in lockmgr (8.x+) # See http://www.mail-archive.com/[email protected]/msg10782.html options ADAPTIVE_LOCKMGRS # UTF-8 in console (9.x+) #options TEKEN_UTF8 #options TEKEN_XTERM # NCQ support # WARNING! all ad[0-9]+ devices will be renamed to ada[0-9]+ #options ATA_CAM # FreeBSD 9+ # Deadlock resolver thread # For additional information see http://www.mail-archive.com/[email protected]/msg18124.html #options DEADLKRES PS. Also most of FreeBSD's limits can be monitored by # vmstat -z and # limits PPS. variety of network counters can be monitored via # netstat -s In FreeBSD-9 netstat's -Q option appeared, try following command to display netisr stats # netstat -Q PPPS. also see # man 7 tuning PPPPS. I wanted to thank FreeBSD community, especially author of nginx - Igor Sysoev, nginx-ru@ and FreeBSD-performance@ mailing lists for providing useful information about FreeBSD tuning. So here is the question: What tunings are you using on yours FreeBSD servers? You can also post your /etc/sysctl.conf, /boot/loader.conf, kernel options, etc with description of its' meaning (do not copy-paste from sysctl -d). Don't forget to specify server type (web, smb, gateway, etc) Let's share experience!

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• high load average, high wait, dmesg raid error messages (debian nfs server)

  - by John Stumbles

  Debian 6 on HP proliant (2 CPU) with raid (2*1.5T RAID1 + 2*2T RAID1 joined RAID0 to make 3.5T) running mainly nfs & imapd (plus samba for windows share & local www for previewing web pages); with local ubuntu desktop client mounting $HOME, laptops accessing imap & odd files (e.g. videos) via nfs/smb; boxes connected 100baseT or wifi via home router/switch uname -a Linux prole 2.6.32-5-686 #1 SMP Wed Jan 11 12:29:30 UTC 2012 i686 GNU/Linux Setup has been working for months but prone to intermittently going very slow (user experience on desktop mounting $HOME from server, or laptop playing videos) and now consistently so bad I've had to delve into it to try to find what's wrong(!) Server seems OK at low load e.g. (laptop) client (with $HOME on local disk) connecting to server's imapd and nfs mounting RAID to access 1 file: top shows load ~ 0.1 or less, 0 wait but when (desktop) client mounts $HOME and starts user KDE session (all accessing server) then top shows e.g. top - 13:41:17 up 3:43, 3 users, load average: 9.29, 9.55, 8.27 Tasks: 158 total, 1 running, 157 sleeping, 0 stopped, 0 zombie Cpu(s): 0.4%us, 0.4%sy, 0.0%ni, 49.0%id, 49.7%wa, 0.0%hi, 0.5%si, 0.0%st Mem: 903856k total, 851784k used, 52072k free, 171152k buffers Swap: 0k total, 0k used, 0k free, 476896k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 3935 root 20 0 2456 1088 784 R 2 0.1 0:00.02 top 1 root 20 0 2028 680 584 S 0 0.1 0:01.14 init 2 root 20 0 0 0 0 S 0 0.0 0:00.00 kthreadd 3 root RT 0 0 0 0 S 0 0.0 0:00.00 migration/0 4 root 20 0 0 0 0 S 0 0.0 0:00.12 ksoftirqd/0 5 root RT 0 0 0 0 S 0 0.0 0:00.00 watchdog/0 6 root RT 0 0 0 0 S 0 0.0 0:00.00 migration/1 7 root 20 0 0 0 0 S 0 0.0 0:00.16 ksoftirqd/1 8 root RT 0 0 0 0 S 0 0.0 0:00.00 watchdog/1 9 root 20 0 0 0 0 S 0 0.0 0:00.42 events/0 10 root 20 0 0 0 0 S 0 0.0 0:02.26 events/1 11 root 20 0 0 0 0 S 0 0.0 0:00.00 cpuset 12 root 20 0 0 0 0 S 0 0.0 0:00.00 khelper 13 root 20 0 0 0 0 S 0 0.0 0:00.00 netns 14 root 20 0 0 0 0 S 0 0.0 0:00.00 async/mgr 15 root 20 0 0 0 0 S 0 0.0 0:00.00 pm 16 root 20 0 0 0 0 S 0 0.0 0:00.02 sync_supers 17 root 20 0 0 0 0 S 0 0.0 0:00.02 bdi-default 18 root 20 0 0 0 0 S 0 0.0 0:00.00 kintegrityd/0 19 root 20 0 0 0 0 S 0 0.0 0:00.00 kintegrityd/1 20 root 20 0 0 0 0 S 0 0.0 0:00.02 kblockd/0 21 root 20 0 0 0 0 S 0 0.0 0:00.08 kblockd/1 22 root 20 0 0 0 0 S 0 0.0 0:00.00 kacpid 23 root 20 0 0 0 0 S 0 0.0 0:00.00 kacpi_notify 24 root 20 0 0 0 0 S 0 0.0 0:00.00 kacpi_hotplug 25 root 20 0 0 0 0 S 0 0.0 0:00.00 kseriod 28 root 20 0 0 0 0 S 0 0.0 0:04.19 kondemand/0 29 root 20 0 0 0 0 S 0 0.0 0:02.93 kondemand/1 30 root 20 0 0 0 0 S 0 0.0 0:00.00 khungtaskd 31 root 20 0 0 0 0 S 0 0.0 0:00.18 kswapd0 32 root 25 5 0 0 0 S 0 0.0 0:00.00 ksmd 33 root 20 0 0 0 0 S 0 0.0 0:00.00 aio/0 34 root 20 0 0 0 0 S 0 0.0 0:00.00 aio/1 35 root 20 0 0 0 0 S 0 0.0 0:00.00 crypto/0 36 root 20 0 0 0 0 S 0 0.0 0:00.00 crypto/1 203 root 20 0 0 0 0 S 0 0.0 0:00.00 ksuspend_usbd 204 root 20 0 0 0 0 S 0 0.0 0:00.00 khubd 205 root 20 0 0 0 0 S 0 0.0 0:00.00 ata/0 206 root 20 0 0 0 0 S 0 0.0 0:00.00 ata/1 207 root 20 0 0 0 0 S 0 0.0 0:00.14 ata_aux 208 root 20 0 0 0 0 S 0 0.0 0:00.01 scsi_eh_0 dmesg suggests there's a disk problem: .............. (previous episode) [13276.966004] raid1:md0: read error corrected (8 sectors at 489900360 on sdc7) [13276.966043] raid1: sdb7: redirecting sector 489898312 to another mirror [13279.569186] ata4.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x0 [13279.569211] ata4.00: irq_stat 0x40000008 [13279.569230] ata4.00: failed command: READ FPDMA QUEUED [13279.569257] ata4.00: cmd 60/08:00:00:6a:05/00:00:23:00:00/40 tag 0 ncq 4096 in [13279.569262] res 41/40:00:05:6a:05/00:00:23:00:00/40 Emask 0x409 (media error) <F> [13279.569306] ata4.00: status: { DRDY ERR } [13279.569321] ata4.00: error: { UNC } [13279.575362] ata4.00: configured for UDMA/133 [13279.575388] ata4: EH complete [13283.169224] ata4.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x0 [13283.169246] ata4.00: irq_stat 0x40000008 [13283.169263] ata4.00: failed command: READ FPDMA QUEUED [13283.169289] ata4.00: cmd 60/08:00:00:6a:05/00:00:23:00:00/40 tag 0 ncq 4096 in [13283.169294] res 41/40:00:07:6a:05/00:00:23:00:00/40 Emask 0x409 (media error) <F> [13283.169331] ata4.00: status: { DRDY ERR } [13283.169345] ata4.00: error: { UNC } [13283.176071] ata4.00: configured for UDMA/133 [13283.176104] ata4: EH complete [13286.224814] ata4.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x0 [13286.224837] ata4.00: irq_stat 0x40000008 [13286.224853] ata4.00: failed command: READ FPDMA QUEUED [13286.224879] ata4.00: cmd 60/08:00:00:6a:05/00:00:23:00:00/40 tag 0 ncq 4096 in [13286.224884] res 41/40:00:06:6a:05/00:00:23:00:00/40 Emask 0x409 (media error) <F> [13286.224922] ata4.00: status: { DRDY ERR } [13286.224935] ata4.00: error: { UNC } [13286.231277] ata4.00: configured for UDMA/133 [13286.231303] ata4: EH complete [13288.802623] ata4.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x0 [13288.802646] ata4.00: irq_stat 0x40000008 [13288.802662] ata4.00: failed command: READ FPDMA QUEUED [13288.802688] ata4.00: cmd 60/08:00:00:6a:05/00:00:23:00:00/40 tag 0 ncq 4096 in [13288.802693] res 41/40:00:05:6a:05/00:00:23:00:00/40 Emask 0x409 (media error) <F> [13288.802731] ata4.00: status: { DRDY ERR } [13288.802745] ata4.00: error: { UNC } [13288.808901] ata4.00: configured for UDMA/133 [13288.808927] ata4: EH complete [13291.380430] ata4.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x0 [13291.380453] ata4.00: irq_stat 0x40000008 [13291.380470] ata4.00: failed command: READ FPDMA QUEUED [13291.380496] ata4.00: cmd 60/08:00:00:6a:05/00:00:23:00:00/40 tag 0 ncq 4096 in [13291.380501] res 41/40:00:05:6a:05/00:00:23:00:00/40 Emask 0x409 (media error) <F> [13291.380577] ata4.00: status: { DRDY ERR } [13291.380594] ata4.00: error: { UNC } [13291.386517] ata4.00: configured for UDMA/133 [13291.386543] ata4: EH complete [13294.347147] ata4.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action 0x0 [13294.347169] ata4.00: irq_stat 0x40000008 [13294.347186] ata4.00: failed command: READ FPDMA QUEUED [13294.347211] ata4.00: cmd 60/08:00:00:6a:05/00:00:23:00:00/40 tag 0 ncq 4096 in [13294.347217] res 41/40:00:06:6a:05/00:00:23:00:00/40 Emask 0x409 (media error) <F> [13294.347254] ata4.00: status: { DRDY ERR } [13294.347268] ata4.00: error: { UNC } [13294.353556] ata4.00: configured for UDMA/133 [13294.353583] sd 3:0:0:0: [sdc] Unhandled sense code [13294.353590] sd 3:0:0:0: [sdc] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [13294.353599] sd 3:0:0:0: [sdc] Sense Key : Medium Error [current] [descriptor] [13294.353610] Descriptor sense data with sense descriptors (in hex): [13294.353616] 72 03 11 04 00 00 00 0c 00 0a 80 00 00 00 00 00 [13294.353635] 23 05 6a 06 [13294.353644] sd 3:0:0:0: [sdc] Add. Sense: Unrecovered read error - auto reallocate failed [13294.353657] sd 3:0:0:0: [sdc] CDB: Read(10): 28 00 23 05 6a 00 00 00 08 00 [13294.353675] end_request: I/O error, dev sdc, sector 587557382 [13294.353726] ata4: EH complete [13294.366953] raid1:md0: read error corrected (8 sectors at 489900544 on sdc7) [13294.366992] raid1: sdc7: redirecting sector 489898496 to another mirror and they're happening quite frequently, which I guess is liable to account for the performance problem(?) # dmesg | grep mirror [12433.561822] raid1: sdc7: redirecting sector 489900464 to another mirror [12449.428933] raid1: sdb7: redirecting sector 489900504 to another mirror [12464.807016] raid1: sdb7: redirecting sector 489900512 to another mirror [12480.196222] raid1: sdb7: redirecting sector 489900520 to another mirror [12495.585413] raid1: sdb7: redirecting sector 489900528 to another mirror [12510.974424] raid1: sdb7: redirecting sector 489900536 to another mirror [12526.374933] raid1: sdb7: redirecting sector 489900544 to another mirror [12542.619938] raid1: sdc7: redirecting sector 489900608 to another mirror [12559.431328] raid1: sdc7: redirecting sector 489900616 to another mirror [12576.553866] raid1: sdc7: redirecting sector 489900624 to another mirror [12592.065265] raid1: sdc7: redirecting sector 489900632 to another mirror [12607.621121] raid1: sdc7: redirecting sector 489900640 to another mirror [12623.165856] raid1: sdc7: redirecting sector 489900648 to another mirror [12638.699474] raid1: sdc7: redirecting sector 489900656 to another mirror [12655.610881] raid1: sdc7: redirecting sector 489900664 to another mirror [12672.255617] raid1: sdc7: redirecting sector 489900672 to another mirror [12672.288746] raid1: sdc7: redirecting sector 489900680 to another mirror [12672.332376] raid1: sdc7: redirecting sector 489900688 to another mirror [12672.362935] raid1: sdc7: redirecting sector 489900696 to another mirror [12674.201177] raid1: sdc7: redirecting sector 489900704 to another mirror [12698.045050] raid1: sdc7: redirecting sector 489900712 to another mirror [12698.089309] raid1: sdc7: redirecting sector 489900720 to another mirror [12698.111999] raid1: sdc7: redirecting sector 489900728 to another mirror [12698.134006] raid1: sdc7: redirecting sector 489900736 to another mirror [12719.034376] raid1: sdc7: redirecting sector 489900744 to another mirror [12734.545775] raid1: sdc7: redirecting sector 489900752 to another mirror [12734.590014] raid1: sdc7: redirecting sector 489900760 to another mirror [12734.624050] raid1: sdc7: redirecting sector 489900768 to another mirror [12734.647308] raid1: sdc7: redirecting sector 489900776 to another mirror [12734.664657] raid1: sdc7: redirecting sector 489900784 to another mirror [12734.710642] raid1: sdc7: redirecting sector 489900792 to another mirror [12734.721919] raid1: sdc7: redirecting sector 489900800 to another mirror [12734.744732] raid1: sdc7: redirecting sector 489900808 to another mirror [12734.779330] raid1: sdc7: redirecting sector 489900816 to another mirror [12782.604564] raid1: sdb7: redirecting sector 1242934216 to another mirror [12798.264153] raid1: sdc7: redirecting sector 1242935080 to another mirror [13245.832193] raid1: sdb7: redirecting sector 489898296 to another mirror [13261.376929] raid1: sdb7: redirecting sector 489898304 to another mirror [13276.966043] raid1: sdb7: redirecting sector 489898312 to another mirror [13294.366992] raid1: sdc7: redirecting sector 489898496 to another mirror although the arrays are still running on all disks - they haven't given up on any yet: # cat /proc/mdstat Personalities : [raid1] [raid0] md10 : active raid0 md0[0] md1[1] 3368770048 blocks super 1.2 512k chunks md1 : active raid1 sde2[2] sdd2[1] 1464087824 blocks super 1.2 [2/2] [UU] md0 : active raid1 sdb7[0] sdc7[2] 1904684920 blocks super 1.2 [2/2] [UU] unused devices: <none> So I think I have some idea what the problem is but I am not a linux sysadmin expert by the remotest stretch of the imagination and would really appreciate some clue checking here with my diagnosis and what do I need to do: obviously I need to source another drive for sdc. (I'm guessing I could buy a larger drive if the price is right: I'm thinking that one day I'll need to grow the size of the array and that would be one less drive to replace with a larger one) then use mdadm to fail out the existing sdc, remove it and fit the new drive fdisk the new drive with the same size partition for the array as the old one had use mdadm to add the new drive into the array that sound OK?

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• Tomcat 7 taking ages to start up after upgrade

  - by Lawrence

  I recently updated my server installation from Tomcat 6 to Tomcat 7, in order to take advantage of better connection pooling. My project uses Hibernate, for object persistance, a Mysql 5.5.20 database, and memcached for caching. When I was using Tomcat 6, Tomcat would start in about 8 seconds. After moving to Tomcat 7, it now takes between 75 - 80 seconds to start (this is on a Macbook pro 15", core i7 2Ghz, 8Gb of RAM). The only thing that has really changed between during the move from Tomcat 6 to 7 has been my context.xml file, which controls the connection pooling information: <Context antiJARLocking="true" reloadable="true" path=""> <Resource name="jdbc/test-db" auth="Container" type="javax.sql.DataSource" factory="org.apache.tomcat.jdbc.pool.DataSourceFactory" testOnBorrow="true" testOnReturn="false" testWhileIdle="true" validationQuery="SELECT 1" validationQueryTimeout="20000" validationInterval="30000" timeBetweenEvictionRunsMillis="60000" logValidationErrors="true" autoReconnect="true" username="webuser" password="xxxxxxx" driverClassName="com.mysql.jdbc.Driver" url="jdbc:mysql://databasename.us-east-1.rds.amazonaws.com:3306/test-db" maxActive="15" minIdle="2" maxIdle="10" maxWait="10000" maxAge="7200000"/> </Context> Now, as you can see, the database is running on Amazon RDS (where our live servers are), and thus is about 200ms round trip time away from my machine. I have already checked that I have security permissions to that database from my machine, (and anyway, it connects after 75 secs, so it cant be that). My initial thought was that Tomcat 7 and hibernate are doing something weird (like pre-instantiating a bunch of connections or something), and the latency to the database is amplifying the effects. While trying to diagnose the problem, I used jstack to get a stack trace of the Tomcat 7 server while its doing its startup thing. Here is the stack trace... Full thread dump Java HotSpot(TM) 64-Bit Server VM (20.12-b01-434 mixed mode): "Attach Listener" daemon prio=9 tid=7fa4c0038800 nid=0x10c39a000 waiting on condition [00000000] java.lang.Thread.State: RUNNABLE "Abandoned connection cleanup thread" daemon prio=5 tid=7fa4bb810000 nid=0x10f3ba000 in Object.wait() [10f3b9000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <7f40a0070> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:118) - locked <7f40a0070> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:134) at com.mysql.jdbc.NonRegisteringDriver$1.run(NonRegisteringDriver.java:93) "PoolCleaner[545768040:1352724902327]" daemon prio=5 tid=7fa4be852800 nid=0x10e772000 in Object.wait() [10e771000] java.lang.Thread.State: TIMED_WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <7f40c7c90> (a java.util.TaskQueue) at java.util.TimerThread.mainLoop(Timer.java:509) - locked <7f40c7c90> (a java.util.TaskQueue) at java.util.TimerThread.run(Timer.java:462) "localhost-startStop-1" daemon prio=5 tid=7fa4bd034800 nid=0x10d66b000 runnable [10d668000] java.lang.Thread.State: RUNNABLE at java.net.SocketInputStream.socketRead0(Native Method) at java.net.SocketInputStream.read(SocketInputStream.java:129) at com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:114) at com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:161) at com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:189) - locked <7f3673be0> (a com.mysql.jdbc.util.ReadAheadInputStream) at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:3014) at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3467) at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3456) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3997) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2468) at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2629) at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2713) - locked <7f366a1c0> (a com.mysql.jdbc.JDBC4Connection) at com.mysql.jdbc.ConnectionImpl.configureClientCharacterSet(ConnectionImpl.java:1930) at com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3571) at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2445) at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2215) - locked <7f366a1c0> (a com.mysql.jdbc.JDBC4Connection) at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:813) at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47) at sun.reflect.GeneratedConstructorAccessor10.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at com.mysql.jdbc.Util.handleNewInstance(Util.java:411) at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399) at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:334) at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:278) at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:182) at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:699) at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:631) at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:485) at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:143) at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:116) - locked <7f34f0dc8> (a org.apache.tomcat.jdbc.pool.DataSource) at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:103) at org.apache.tomcat.jdbc.pool.DataSourceFactory.createDataSource(DataSourceFactory.java:539) at org.apache.tomcat.jdbc.pool.DataSourceFactory.getObjectInstance(DataSourceFactory.java:237) at org.apache.naming.factory.ResourceFactory.getObjectInstance(ResourceFactory.java:143) at javax.naming.spi.NamingManager.getObjectInstance(NamingManager.java:304) at org.apache.naming.NamingContext.lookup(NamingContext.java:843) at org.apache.naming.NamingContext.lookup(NamingContext.java:154) at org.apache.naming.NamingContext.lookup(NamingContext.java:831) at org.apache.naming.NamingContext.lookup(NamingContext.java:168) at org.apache.catalina.core.NamingContextListener.addResource(NamingContextListener.java:1061) at org.apache.catalina.core.NamingContextListener.createNamingContext(NamingContextListener.java:671) at org.apache.catalina.core.NamingContextListener.lifecycleEvent(NamingContextListener.java:270) at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119) at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5173) - locked <7f46b07f0> (a org.apache.catalina.core.StandardContext) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) - locked <7f46b07f0> (a org.apache.catalina.core.StandardContext) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549) at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303) at java.util.concurrent.FutureTask.run(FutureTask.java:138) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:680) "Catalina-startStop-1" daemon prio=5 tid=7fa4b7a5e800 nid=0x10d568000 waiting on condition [10d567000] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <7f480e970> (a java.util.concurrent.FutureTask$Sync) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:156) at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:811) at java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:969) at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1281) at java.util.concurrent.FutureTask$Sync.innerGet(FutureTask.java:218) at java.util.concurrent.FutureTask.get(FutureTask.java:83) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123) - locked <7f453c630> (a org.apache.catalina.core.StandardHost) at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:800) - locked <7f453c630> (a org.apache.catalina.core.StandardHost) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) - locked <7f453c630> (a org.apache.catalina.core.StandardHost) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549) at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303) at java.util.concurrent.FutureTask.run(FutureTask.java:138) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:680) "GC Daemon" daemon prio=2 tid=7fa4b9912800 nid=0x10d465000 in Object.wait() [10d464000] java.lang.Thread.State: TIMED_WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <7f4506d28> (a sun.misc.GC$LatencyLock) at sun.misc.GC$Daemon.run(GC.java:100) - locked <7f4506d28> (a sun.misc.GC$LatencyLock) "Low Memory Detector" daemon prio=5 tid=7fa4b480b800 nid=0x10c8ae000 runnable [00000000] java.lang.Thread.State: RUNNABLE "C2 CompilerThread1" daemon prio=9 tid=7fa4b480b000 nid=0x10c7ab000 waiting on condition [00000000] java.lang.Thread.State: RUNNABLE "C2 CompilerThread0" daemon prio=9 tid=7fa4b480a000 nid=0x10c6a8000 waiting on condition [00000000] java.lang.Thread.State: RUNNABLE "Signal Dispatcher" daemon prio=9 tid=7fa4b4809800 nid=0x10c5a5000 runnable [00000000] java.lang.Thread.State: RUNNABLE "Surrogate Locker Thread (Concurrent GC)" daemon prio=5 tid=7fa4b4808800 nid=0x10c4a2000 waiting on condition [00000000] java.lang.Thread.State: RUNNABLE "Finalizer" daemon prio=8 tid=7fa4b793f000 nid=0x10c297000 in Object.wait() [10c296000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <7f451c8f0> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:118) - locked <7f451c8f0> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:134) at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:159) "Reference Handler" daemon prio=10 tid=7fa4b793e000 nid=0x10c194000 in Object.wait() [10c193000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <7f452e168> (a java.lang.ref.Reference$Lock) at java.lang.Object.wait(Object.java:485) at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:116) - locked <7f452e168> (a java.lang.ref.Reference$Lock) "main" prio=5 tid=7fa4b7800800 nid=0x104329000 waiting on condition [104327000] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <7f480e9a0> (a java.util.concurrent.FutureTask$Sync) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:156) at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:811) at java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:969) at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1281) at java.util.concurrent.FutureTask$Sync.innerGet(FutureTask.java:218) at java.util.concurrent.FutureTask.get(FutureTask.java:83) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123) - locked <7f451fd90> (a org.apache.catalina.core.StandardEngine) at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:302) - locked <7f451fd90> (a org.apache.catalina.core.StandardEngine) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) - locked <7f451fd90> (a org.apache.catalina.core.StandardEngine) at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443) - locked <7f451fd90> (a org.apache.catalina.core.StandardEngine) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) - locked <7f453e810> (a org.apache.catalina.core.StandardService) at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:732) - locked <7f4506d58> (a [Lorg.apache.catalina.Service;) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) - locked <7f44f7ba0> (a org.apache.catalina.core.StandardServer) at org.apache.catalina.startup.Catalina.start(Catalina.java:684) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:322) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:451) "VM Thread" prio=9 tid=7fa4b7939800 nid=0x10c091000 runnable "Gang worker#0 (Parallel GC Threads)" prio=9 tid=7fa4b7802000 nid=0x10772b000 runnable "Gang worker#1 (Parallel GC Threads)" prio=9 tid=7fa4b7802800 nid=0x10782e000 runnable "Gang worker#2 (Parallel GC Threads)" prio=9 tid=7fa4b7803000 nid=0x107931000 runnable "Gang worker#3 (Parallel GC Threads)" prio=9 tid=7fa4b7804000 nid=0x107a34000 runnable "Gang worker#4 (Parallel GC Threads)" prio=9 tid=7fa4b7804800 nid=0x107b37000 runnable "Gang worker#5 (Parallel GC Threads)" prio=9 tid=7fa4b7805000 nid=0x107c3a000 runnable "Gang worker#6 (Parallel GC Threads)" prio=9 tid=7fa4b7805800 nid=0x107d3d000 runnable "Gang worker#7 (Parallel GC Threads)" prio=9 tid=7fa4b7806800 nid=0x107e40000 runnable "Concurrent Mark-Sweep GC Thread" prio=9 tid=7fa4b78e3800 nid=0x10bd0b000 runnable "Gang worker#0 (Parallel CMS Threads)" prio=9 tid=7fa4b78e2800 nid=0x10b305000 runnable "Gang worker#1 (Parallel CMS Threads)" prio=9 tid=7fa4b78e3000 nid=0x10b408000 runnable "VM Periodic Task Thread" prio=10 tid=7fa4b4815800 nid=0x10c9b1000 waiting on condition "Exception Catcher Thread" prio=10 tid=7fa4b7801800 nid=0x104554000 runnable JNI global references: 919 The only thing I can figure out from this is that it looks like the mysql jdbc drivers might have something to do with the long start up (the various stack traces I took during the start up process all pretty much look the same as this). Could anyone shed some light on what might be causing this? Have I done something dense in my context.xml? Is hibernate perhaps to blame?

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• I need advices: small memory footprint linux mail server with spam filtering

  - by petermolnar

  I have a VPS which is originally destined to be a webserver but some minimal mail capabilities are needed to be deployed as well, including sending and receiving as standalone server. The current setup is the following: Postfix reveices the mail, the users are in virtual tables, stored in MySQL on connection all servers are tested with policyd-weight service against some DNSBLs all mail is runs through SpamAssassin spamd with the help of spamc client the mail is then delivered with Dovecot 2' LDA (local delivery agent), virtual users as well As you saw... there's no virus scanner running, and that's for a reason: clamav eats all the memory possible and also, virus mails are all filtered out with this setup (I've tested the same with ClamAV enabled for 1,5 years, no virus mail ever got even to ClamAV) I don't use amavisd and I really don't want to. You only need that monster if you have plenty of memory and lots of simultaneous scanners. It's also a nightmare to fine tune by hand. I run policyd-weight instead of policyd and native DNSBLs in postfix. I don't like to send someone away because a single service listed them. Important statement: everything works fine. I receive very small amount of spam, nearly never get a false positive and most of the bad mail is stopped by policyd-weight. The only "problem" that I feel the services at total uses a bit much memory alltogether. I've already cut the modules of spamassassin (see below), but I'd really like to hear some advices how to cut the memory footprint as low as possible, mostly: what plugins SpamAssassin really needs and what are more or less useless, regarding to my current postfix & policyd-weight setup? SpamAssassin rules are also compiled with sa-compile (sa-update runs once a week from cron, compile runs right after that) These are some of the current configurations that may matter, please tell me if you need anything more. postfix/master.cf (parts only) dovecot unix - n n - - pipe flags=DRhu user=vmail:vmail argv=/usr/bin/spamc -e /usr/lib/dovecot/deliver -d ${recipient} -f {sender} postfix/main.cf (parts only) smtpd_helo_required = yes smtpd_helo_restrictions = permit_mynetworks, reject_invalid_hostname, permit smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_invalid_hostname, reject_non_fqdn_hostname, reject_non_fqdn_recipient, reject_unknown_recipient_domain, reject_unauth_pipelining, reject_unauth_destination, check_policy_service inet:127.0.0.1:12525, permit policyd-weight.conf (parts only) $REJECTMSG = "550 Mail appeared to be SPAM or forged. Ask your Mail/DNS-Administrator to correct HELO and DNS MX settings or to get removed from DNSBLs"; $REJECTLEVEL = 4; $DEFER_STRING = 'IN_SPAMCOP= BOGUS_MX='; $DEFER_ACTION = '450'; $DEFER_LEVEL = 5; $DNSERRMSG = '450 No DNS entries for your MTA, HELO and Domain. Contact YOUR administrator'; # 1: ON, 0: OFF (default) # If ON request that ALL clients are only checked against RBLs $dnsbl_checks_only = 0; # 1: ON (default), 0: OFF # When set to ON it logs only RBLs which affect scoring (positive or negative) $LOG_BAD_RBL_ONLY = 1; ## DNSBL settings @dnsbl_score = ( # host, hit, miss, log name 'dnsbl.ahbl.org', 3, -1, 'dnsbl.ahbl.org', 'dnsbl.njabl.org', 3, -1, 'dnsbl.njabl.org', 'dnsbl.sorbs.net', 3, -1, 'dnsbl.sorbs.net', 'bl.spamcop.net', 3, -1, 'bl.spamcop.net', 'zen.spamhaus.org', 3, -1, 'zen.spamhaus.org', 'pbl.spamhaus.org', 3, -1, 'pbl.spamhaus.org', 'cbl.abuseat.org', 3, -1, 'cbl.abuseat.org', 'list.dsbl.org', 3, -1, 'list.dsbl.org', ); # If Client IP is listed in MORE DNSBLS than this var, it gets REJECTed immediately $MAXDNSBLHITS = 3; # alternatively, if the score of DNSBLs is ABOVE this level, reject immediately $MAXDNSBLSCORE = 9; $MAXDNSBLMSG = '550 Az levelezoszerveruk IP cime tul sok spamlistan talahato, kerjuk ellenorizze! / Your MTA is listed in too many DNSBLs; please check.'; ## RHSBL settings @rhsbl_score = ( 'multi.surbl.org', 4, 0, 'multi.surbl.org', 'rhsbl.ahbl.org', 4, 0, 'rhsbl.ahbl.org', 'dsn.rfc-ignorant.org', 4, 0, 'dsn.rfc-ignorant.org', # 'postmaster.rfc-ignorant.org', 0.1, 0, 'postmaster.rfc-ignorant.org', # 'abuse.rfc-ignorant.org', 0.1, 0, 'abuse.rfc-ignorant.org' ); # skip a RBL if this RBL had this many continuous errors $BL_ERROR_SKIP = 2; # skip a RBL for that many times $BL_SKIP_RELEASE = 10; ## cache stuff # must be a directory (add trailing slash) $LOCKPATH = '/var/run/policyd-weight/'; # socket path for the cache daemon. $SPATH = $LOCKPATH.'/polw.sock'; # how many seconds the cache may be idle before starting maintenance routines #NOTE: standard maintenance jobs happen regardless of this setting. $MAXIDLECACHE = 60; # after this number of requests do following maintenance jobs: checking for config changes $MAINTENANCE_LEVEL = 5; # negative (i.e. SPAM) result cache settings ################################## # set to 0 to disable caching for spam results. To this level the cache will be cleaned. $CACHESIZE = 2000; # at this number of entries cleanup takes place $CACHEMAXSIZE = 4000; $CACHEREJECTMSG = '550 temporarily blocked because of previous errors'; # after NTTL retries the cache entry is deleted $NTTL = 1; # client MUST NOT retry within this seconds in order to decrease TTL counter $NTIME = 30; # positve (i.,e. HAM) result cache settings ################################### # set to 0 to disable caching of HAM. To this number of entries the cache will be cleaned $POSCACHESIZE = 1000; # at this number of entries cleanup takes place $POSCACHEMAXSIZE = 2000; $POSCACHEMSG = 'using cached result'; #after PTTL requests the HAM entry must succeed one time the RBL checks again $PTTL = 60; # after $PTIME in HAM Cache the client must pass one time the RBL checks again. #Values must be nonfractal. Accepted time-units: s, m, h, d $PTIME = '3h'; # The client must pass this time the RBL checks in order to be listed as hard-HAM # After this time the client will pass immediately for PTTL within PTIME $TEMP_PTIME = '1d'; ## DNS settings # Retries for ONE DNS-Lookup $DNS_RETRIES = 1; # Retry-interval for ONE DNS-Lookup $DNS_RETRY_IVAL = 5; # max error count for unresponded queries in a complete policy query $MAXDNSERR = 3; $MAXDNSERRMSG = 'passed - too many local DNS-errors'; # persistent udp connection for DNS queries. #broken in Net::DNS version 0.51. Works with Net::DNS 0.53; DEFAULT: off $PUDP= 0; # Force the usage of Net::DNS for RBL lookups. # Normally policyd-weight tries to use a faster RBL lookup routine instead of Net::DNS $USE_NET_DNS = 0; # A list of space separated NS IPs # This overrides resolv.conf settings # Example: $NS = '1.2.3.4 1.2.3.5'; # DEFAULT: empty $NS = ''; # timeout for receiving from cache instance $IPC_TIMEOUT = 2; # If set to 1 policyd-weight closes connections to smtpd clients in order to avoid too many #established connections to one policyd-weight child $TRY_BALANCE = 0; # scores for checks, WARNING: they may manipulate eachother # or be factors for other scores. # HIT score, MISS Score @client_ip_eq_helo_score = (1.5, -1.25 ); @helo_score = (1.5, -2 ); @helo_score = (0, -2 ); @helo_from_mx_eq_ip_score= (1.5, -3.1 ); @helo_numeric_score= (2.5, 0 ); @from_match_regex_verified_helo= (1,-2 ); @from_match_regex_unverified_helo = (1.6, -1.5 ); @from_match_regex_failed_helo = (2.5, 0 ); @helo_seems_dialup = (1.5, 0 ); @failed_helo_seems_dialup= (2, 0 ); @helo_ip_in_client_subnet= (0,-1.2 ); @helo_ip_in_cl16_subnet = (0,-0.41 ); #@client_seems_dialup_score = (3.75, 0 ); @client_seems_dialup_score = (0, 0 ); @from_multiparted = (1.09, 0 ); @from_anon= (1.17, 0 ); @bogus_mx_score = (2.1, 0 ); @random_sender_score = (0.25, 0 ); @rhsbl_penalty_score = (3.1, 0 ); @enforce_dyndns_score = (3, 0 ); spamassassin/init.pre (I've put the .pre files together) loadplugin Mail::SpamAssassin::Plugin::Hashcash loadplugin Mail::SpamAssassin::Plugin::SPF loadplugin Mail::SpamAssassin::Plugin::Pyzor loadplugin Mail::SpamAssassin::Plugin::Razor2 loadplugin Mail::SpamAssassin::Plugin::AutoLearnThreshold loadplugin Mail::SpamAssassin::Plugin::MIMEHeader loadplugin Mail::SpamAssassin::Plugin::ReplaceTags loadplugin Mail::SpamAssassin::Plugin::Check loadplugin Mail::SpamAssassin::Plugin::HTTPSMismatch loadplugin Mail::SpamAssassin::Plugin::URIDetail loadplugin Mail::SpamAssassin::Plugin::Bayes loadplugin Mail::SpamAssassin::Plugin::BodyEval loadplugin Mail::SpamAssassin::Plugin::DNSEval loadplugin Mail::SpamAssassin::Plugin::HTMLEval loadplugin Mail::SpamAssassin::Plugin::HeaderEval loadplugin Mail::SpamAssassin::Plugin::MIMEEval loadplugin Mail::SpamAssassin::Plugin::RelayEval loadplugin Mail::SpamAssassin::Plugin::URIEval loadplugin Mail::SpamAssassin::Plugin::WLBLEval loadplugin Mail::SpamAssassin::Plugin::VBounce loadplugin Mail::SpamAssassin::Plugin::Rule2XSBody spamassassin/local.cf (parts) use_bayes 1 bayes_auto_learn 1 bayes_store_module Mail::SpamAssassin::BayesStore::MySQL bayes_sql_dsn DBI:mysql:db:127.0.0.1:3306 bayes_sql_username user bayes_sql_password pass bayes_ignore_header X-Bogosity bayes_ignore_header X-Spam-Flag bayes_ignore_header X-Spam-Status ### User settings user_scores_dsn DBI:mysql:db:127.0.0.1:3306 user_scores_sql_password user user_scores_sql_username pass user_scores_sql_custom_query SELECT preference, value FROM _TABLE_ WHERE username = _USERNAME_ OR username = '$GLOBAL' OR username = CONCAT('%',_DOMAIN_) ORDER BY username ASC # for better speed score DNS_FROM_AHBL_RHSBL 0 score __RFC_IGNORANT_ENVFROM 0 score DNS_FROM_RFC_DSN 0 score DNS_FROM_RFC_BOGUSMX 0 score __DNS_FROM_RFC_POST 0 score __DNS_FROM_RFC_ABUSE 0 score __DNS_FROM_RFC_WHOIS 0 UPDATE 01 As adaptr advised I remove policyd-weight and configured postfix postscreen, this resulted approximately -15-20 MB from RAM usage and a lot faster work. I'm not sure it's working at full capacity but it seems promising.

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• PC powers off at random times

  - by Timo Huovinen

  Short Version After experiencing some problems with Mobo batteries my PC started to power off at random times, the power off is instant and sudden and does not restart afterwards, need help figuring out the cause. Facts: Powers off when PC is playing games Powers off when PC is idle Powers off when PC is in safe mode Powers off when PC is in BIOS Powers off when PC is booted through a Windows installation USB Replaced the motherboard battery several times Replaced the 650W PSU with a 750W PSU Replaced the RAM Swapped the RAM between slots Re-applied thermal paste to the CPU Checked if the motherboard touches the case Nothing is overclocked PC Specs PC specs: OS: Windows 7 Ultimate SP1 RAM: klingston 1333MHz 4GB stick CPU: AMD Phenom II x4 955 Mobo: Gigabyte 88GMA-UD2H rev 2.2 Motherboard battery: CR2032 3v HDD: 500GB Seagate ST3500418AS ATA Device Graphics: ATI/AMD Radeon HD 6870 Very Long version Around 10 months ago I built a brand new gaming PC. Around 6 months ago it's time setting in windows started resetting to the year 2010. I swapped the Motherboard battery for a new one of the exact same size and shape and voltage, and the problems disappeared...for around 2 weeks. Then the same problem happened again, time gets reset, I swapped the battery again, and the problem was gone for good and everything was great for about 3 months.. then another problem started happening, the PC started to power off suddenly and without warning at completely random times, sometimes the PC works for and hour, sometimes 5 minutes. So I read on the forums that it might be either the PSU or the motherboard Battery or RAM or HDD or the Graphics card or the CPU or the motherboard or the drivers or a Virus or Grounding issues, or something short circuiting, basically it can be anything... I spent some days researching, and decided to remove the possibility of a virus. I reset the CMOS, cleared all BIOS settings and reinstalled windows 7 after a full format of the HDD, but the random power off kept happening. I then disabled the restart on error option in windows and looked at the event log for error events, but they did not help me figure out the problem. Network list service depends on network location awareness the dependency group failed to start Source Kernel Power Event 41 Task Category 63 Source Disk Event ID 11 Task Category None The driver detected a controller error on device disk I took apart the PC, every little piece, re-applied some expensive thermal paste to the CPU, and double checked that none of the pieces are touching the PC case. The problem was gone, the PC no longer powered off randomly I re-attached the graphics card and all was good for 4 months... then the power off problem appeared again, but was happening at high intervals, the PC would shutdown once in 2 days on average, at random points in time, sometimes when it's idle all day long, sometimes when it's running CRYSIS 2. I checked the CPU temperature, because I know that AMD CPU's have a built in protection mechanism that switches off the PC if the CPU gets too hot, and the Temp was 50C system temp, and 45C CPU after running the PC all day long (I did not do tests to see if there are any temperature spikes, don't know how to do them) Originally the PSU that powered the PC was 650Watts and had one 4 pin cable to power the CPU, I replaced it with a new 750Watts PSU which has two 4 pin cables for the CPU, but the problem remained. I removed the graphics card and let the motherboard use the built in one, but the PC kept suddenly powering off at random times. I took apart the PC completely again, and re-applied thermal paste to the CPU, added lots of insulation, and checked for any type of short-circuit possibility again and again, but the problem remained. The problem was like that for some months. I replaced the Battery a couple of times over the time, changed lots of options in windows, and tried everything I could, but it kept powering off, so I stopped using the PC as much as I used to, just living with the random power offs from time to time, until a couple of days ago, when the power off happens almost immediately after powering on the PC. I replaced the RAM with a brand new one, but that did not help. Took apart the PC again, checked for anything anywhere that might cause it, found some small scratches on the very edge of the motherboard to the left of the PCI express x16 slot. This might cause the problem, I thought, but the scratch looks very superficial, not deep at all, and if the scratch did harm the motherboard, wouldn't it cause it to not start at all? And why did it start to power off a while ago, and then suddenly stop powering off? The scratches could not have vanished??? did chkdsk \d but it powered off when it was at 75% I removed the hard disks, the graphics card, while I fiddled with the BIOS settings, and suddenly the PC shut down while I was looking at the BIOS version. This makes me realize, it is not caused by: HDD, Windows, Drivers or the Graphics card I cleared the CMOS again, updated the BIOS from F5 to F6f beta, but that did not help, it might even seem that the PC powers off even sooner. The shutdown even happened to me while I booted through a windows 7 installation USB and was in the repair console. I removed one of the cables powering the CPU, now only one 4pin cable powers it, and it worked for 30mins after doing that, which makes me think that it's the CPU overheating, and because it gets less power, it overheats slower? The things that I am still considering: CPU overheating (does not seem to overheat, maybe false readings?) Motherboard short circuiting (faulty motherboard?) I desperately need some advice in what is faulty, is it a faulty Motherboard or an overheating CPU? or maybe something else? I have been breaking my head over this problem over a span of 6 months. I'm not sure if this is a good place to ask this question, if it is not, then tell me where I can get some experienced help. More info I have also discovered a mysterious piece that seems to have fallen out of the motherboard i119.photobucket.com/albums/o126/yurikolovsky/strangepiece.jpg What is it? Looks like each time that it powers off the datetime gets reset I also found another forum post tomshardware.co.uk/forum/… except I don't have Integrated PeripheralsUSB Keyboard Function option in BIOS :S Comments summary (asked by Random moderator) Q. tell me, if the computer restarts, is it immediately? Does it take a second and then restarts? Do you see (BSOD) or hear (PSU, short circuit) any suspicious when it happens? After reading trough it, it remains the mainboard that is faulty. – JohannesM A. Immediate power off, all the fans stop instantly, all the light turn off instantly, no sound or anything, and it remains off until I turn it back on. Thanks for the feedback, faulty motherboard is what I fear. Q. Try stress-testing the system with Prime95 and see if errors or shutdowns occur when the CPU is under full load. – speakr A. Prime95 heat stress test peaked CPU heat at 60C after 5mins, it powered off after 30mins of testing in the middle of the test with no errors, Prime95 Heat test or the stress-testing with low RAM usage (small or in-place FFTs) do not report errors while testing for 10-60 mins. The power off does not seem like it is affected by Prime95 at all Makes me wonder if it's a CPU or Motherboard issue at all. Q. I had similar random/intermittent problems with my old board. It gave one of a few different symptoms: keyboard and/or mouse would die and/or the RAM wouldn't work and/or it would shut down. It was in bad shape. One problems was that my old PSU had literally burned the connector on it (browned around the pins), another was that a broken lead inside the layers of the PCB would work sometimes if it happened to be hot or if I bent the board—by jamming a hunk of wood behind it. I managed to keep the board alive for several years, but eventually nothing I did would make it work correctly anymore. – Synetech A. I will try that as the last resort, ok? ;) Q. Have you tried a different power cord, surge protector, outlet (on a different circuit). It's worth a shot just to ensure it's not subpar wiring or a week circuit (dips in power may cause shutdown if the PSU can't pull enough juice from the wall). – Kyle A. yes, I attached the PC to an entirely different outlet on a different circuit and the problem persists. After connecting it to a different outlet after starting the PC it gave me 3 long beeps and 1 short one, then the PC immediately proceeded to boot up normally. Q. Re-check your mainboard manual and all PSU connections to your mainboard to be sure that nothing is missing (e.g. 12V ATX 4-pin/6-pin connector). If you can provoke shutdowns with Prime95, then consider buying new hardware -- a stable system should run Prime95 for 24h without any errors. Prime95 mentions errors in the log when they occur and gives a summary after the stress test was stopped manually (e.g. "0 errors, 0 warnings", if all is fine) – speakr A. Re-checked, there are no more PSU connectors that I can physically connect, except the one ATX 4-pin (there are 2 that power the CPU) that I disconnected on purpose, I have reconnected it but the problem persists. Q. With one PC I had a short curcuit. The power button on the front plate had its cables soldered, but not isolated, and the contacts were very close to the metal case. A heavier touch was enough to cause a shutdown. The PC's vibration could be enough – ott-- A. yes, it seems to switch off with even the lightest touch, I switched on the PC, then pulled out the front panel power cable that connects to the motherboard so the power button does not work anymore, after 5 mins of working like that, with the power button completely disconnected, just sitting idle, the PC powered off again, I don't think it's the power button. Q. I wonder if you dare to operate components without the case, that is remove motherboard, power, disk ( just put the motherboard on a wooden desk). Don't bend the adapters when running like that. – ott-- A. yes, I do dare to do that, but only tomorrow, too tired/late right now.

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• MySQL query, 2 similar servers, 2 minute difference in execution times

  - by mr12086

  I had a similar question on stack overflow, but it seems to be more server/mysql setup related than coding. The queries below all execute instantly on our development server where as they can take upto 2 minutes 20 seconds. The query execution time seems to be affected by home ambiguous the LIKE string's are. If they closely match a country that has few matches it will take less time, and if you use something like 'ge' for germany - it will take longer to execute. But this doesn't always work out like that, at times its quite erratic. Sending data appears to be the culprit but why and what does that mean. Also memory on production looks to be quite low (free memory)? Production: Intel Quad Xeon E3-1220 3.1GHz 4GB DDR3 2x 1TB SATA in RAID1 Network speed 100Mb Ubuntu Development Intel Core i3-2100, 2C/4T, 3.10GHz 500 GB SATA - No RAID 4GB DDR3 UPDATE 2 : mysqltuner output: [prod] -------- General Statistics -------------------------------------------------- [--] Skipped version check for MySQLTuner script [OK] Currently running supported MySQL version 5.1.61-0ubuntu0.10.04.1 [OK] Operating on 64-bit architecture -------- Storage Engine Statistics ------------------------------------------- [--] Status: +Archive -BDB -Federated +InnoDB -ISAM -NDBCluster [--] Data in MyISAM tables: 103M (Tables: 180) [--] Data in InnoDB tables: 491M (Tables: 19) [!!] Total fragmented tables: 38 -------- Security Recommendations ------------------------------------------- [OK] All database users have passwords assigned -------- Performance Metrics ------------------------------------------------- [--] Up for: 77d 4h 6m 1s (53M q [7.968 qps], 14M conn, TX: 87B, RX: 12B) [--] Reads / Writes: 98% / 2% [--] Total buffers: 58.0M global + 2.7M per thread (151 max threads) [OK] Maximum possible memory usage: 463.8M (11% of installed RAM) [OK] Slow queries: 0% (12K/53M) [OK] Highest usage of available connections: 22% (34/151) [OK] Key buffer size / total MyISAM indexes: 16.0M/10.6M [OK] Key buffer hit rate: 98.7% (162M cached / 2M reads) [OK] Query cache efficiency: 20.7% (7M cached / 36M selects) [!!] Query cache prunes per day: 3934 [OK] Sorts requiring temporary tables: 1% (3K temp sorts / 230K sorts) [!!] Joins performed without indexes: 71068 [OK] Temporary tables created on disk: 24% (3M on disk / 13M total) [OK] Thread cache hit rate: 99% (690 created / 14M connections) [!!] Table cache hit rate: 0% (64 open / 85M opened) [OK] Open file limit used: 12% (128/1K) [OK] Table locks acquired immediately: 99% (16M immediate / 16M locks) [!!] InnoDB data size / buffer pool: 491.9M/8.0M -------- Recommendations ----------------------------------------------------- General recommendations: Run OPTIMIZE TABLE to defragment tables for better performance Enable the slow query log to troubleshoot bad queries Adjust your join queries to always utilize indexes Increase table_cache gradually to avoid file descriptor limits Variables to adjust: query_cache_size (> 16M) join_buffer_size (> 128.0K, or always use indexes with joins) table_cache (> 64) innodb_buffer_pool_size (>= 491M) [dev] -------- General Statistics -------------------------------------------------- [--] Skipped version check for MySQLTuner script [OK] Currently running supported MySQL version 5.1.62-0ubuntu0.11.10.1 [!!] Switch to 64-bit OS - MySQL cannot currently use all of your RAM -------- Storage Engine Statistics ------------------------------------------- [--] Status: +Archive -BDB -Federated +InnoDB -ISAM -NDBCluster [--] Data in MyISAM tables: 185M (Tables: 632) [--] Data in InnoDB tables: 967M (Tables: 38) [!!] Total fragmented tables: 73 -------- Security Recommendations ------------------------------------------- [OK] All database users have passwords assigned -------- Performance Metrics ------------------------------------------------- [--] Up for: 1d 2h 26m 9s (5K q [0.058 qps], 1K conn, TX: 4M, RX: 1M) [--] Reads / Writes: 99% / 1% [--] Total buffers: 58.0M global + 2.7M per thread (151 max threads) [OK] Maximum possible memory usage: 463.8M (11% of installed RAM) [OK] Slow queries: 0% (0/5K) [OK] Highest usage of available connections: 1% (2/151) [OK] Key buffer size / total MyISAM indexes: 16.0M/18.6M [OK] Key buffer hit rate: 99.9% (60K cached / 36 reads) [OK] Query cache efficiency: 44.5% (1K cached / 2K selects) [OK] Query cache prunes per day: 0 [OK] Sorts requiring temporary tables: 0% (0 temp sorts / 44 sorts) [OK] Temporary tables created on disk: 24% (162 on disk / 666 total) [OK] Thread cache hit rate: 99% (2 created / 1K connections) [!!] Table cache hit rate: 1% (64 open / 4K opened) [OK] Open file limit used: 8% (88/1K) [OK] Table locks acquired immediately: 100% (1K immediate / 1K locks) [!!] InnoDB data size / buffer pool: 967.7M/8.0M -------- Recommendations ----------------------------------------------------- General recommendations: Run OPTIMIZE TABLE to defragment tables for better performance Enable the slow query log to troubleshoot bad queries Increase table_cache gradually to avoid file descriptor limits Variables to adjust: table_cache (> 64) innodb_buffer_pool_size (>= 967M) UPDATE 1: When testing the queries listed here there is usually no more than one other query taking place, and usually none. Because production is actually handling apache requests that development gets very few of as it's only myself and 1 other who accesses it - could the 4GB of RAM be getting exhausted by using the single machine for both apache and mysql server? Production: sudo hdparm -tT /dev/sda /dev/sda: Timing cached reads: 24872 MB in 2.00 seconds = 12450.72 MB/sec Timing buffered disk reads: 368 MB in 3.00 seconds = 122.49 MB/sec sudo hdparm -tT /dev/sdb /dev/sdb: Timing cached reads: 24786 MB in 2.00 seconds = 12407.22 MB/sec Timing buffered disk reads: 350 MB in 3.00 seconds = 116.53 MB/sec Server version(mysql + ubuntu versions): 5.1.61-0ubuntu0.10.04.1 Development: sudo hdparm -tT /dev/sda /dev/sda: Timing cached reads: 10632 MB in 2.00 seconds = 5319.40 MB/sec Timing buffered disk reads: 400 MB in 3.01 seconds = 132.85 MB/sec Server version(mysql + ubuntu versions): 5.1.62-0ubuntu0.11.10.1 ORIGINAL DATA : This query is NOT the query in question but is related so ill post it. SELECT f.form_question_has_answer_id FROM form_question_has_answer f INNER JOIN project_company_has_user p ON f.form_question_has_answer_user_id = p.project_company_has_user_user_id INNER JOIN company c ON p.project_company_has_user_company_id = c.company_id INNER JOIN project p2 ON p.project_company_has_user_project_id = p2.project_id INNER JOIN user u ON p.project_company_has_user_user_id = u.user_id INNER JOIN form f2 ON p.project_company_has_user_project_id = f2.form_project_id WHERE (f2.form_template_name = 'custom' AND p.project_company_has_user_garbage_collection = 0 AND p.project_company_has_user_project_id = '29') AND (LCASE(c.company_country) LIKE '%ge%' OR LCASE(c.company_country) LIKE '%abcde%') AND f.form_question_has_answer_form_id = '174' And the explain plan for the above query is, run on both dev and production produce the same plan. +----+-------------+-------+--------+----------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------+---------+----------------------------------------------------+------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+--------+----------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------+---------+----------------------------------------------------+------+-------------+ | 1 | SIMPLE | p2 | const | PRIMARY | PRIMARY | 4 | const | 1 | Using index | | 1 | SIMPLE | f | ref | form_question_has_answer_form_id,form_question_has_answer_user_id | form_question_has_answer_form_id | 4 | const | 796 | Using where | | 1 | SIMPLE | u | eq_ref | PRIMARY | PRIMARY | 4 | new_klarents.f.form_question_has_answer_user_id | 1 | Using index | | 1 | SIMPLE | p | ref | project_company_has_user_unique_key,project_company_has_user_user_id,project_company_has_user_company_id,project_company_has_user_project_id | project_company_has_user_user_id | 4 | new_klarents.f.form_question_has_answer_user_id | 1 | Using where | | 1 | SIMPLE | f2 | ref | form_project_id | form_project_id | 4 | const | 15 | Using where | | 1 | SIMPLE | c | eq_ref | PRIMARY | PRIMARY | 4 | new_klarents.p.project_company_has_user_company_id | 1 | Using where | +----+-------------+-------+--------+----------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------+---------+----------------------------------------------------+------+-------------+ This query takes 2 minutes ~20 seconds to execute. The query that is ACTUALLY being run on the server is this one: SELECT COUNT(*) AS num_results FROM (SELECT f.form_question_has_answer_id FROM form_question_has_answer f INNER JOIN project_company_has_user p ON f.form_question_has_answer_user_id = p.project_company_has_user_user_id INNER JOIN company c ON p.project_company_has_user_company_id = c.company_id INNER JOIN project p2 ON p.project_company_has_user_project_id = p2.project_id INNER JOIN user u ON p.project_company_has_user_user_id = u.user_id INNER JOIN form f2 ON p.project_company_has_user_project_id = f2.form_project_id WHERE (f2.form_template_name = 'custom' AND p.project_company_has_user_garbage_collection = 0 AND p.project_company_has_user_project_id = '29') AND (LCASE(c.company_country) LIKE '%ge%' OR LCASE(c.company_country) LIKE '%abcde%') AND f.form_question_has_answer_form_id = '174' GROUP BY f.form_question_has_answer_id;) dctrn_count_query; With explain plans (again same on dev and production): +----+-------------+-------+--------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------+---------+----------------------------------------------------+------+------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+--------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------+---------+----------------------------------------------------+------+------------------------------+ | 1 | PRIMARY | NULL | NULL | NULL | NULL | NULL | NULL | NULL | Select tables optimized away | | 2 | DERIVED | p2 | const | PRIMARY | PRIMARY | 4 | | 1 | Using index | | 2 | DERIVED | f | ref | form_question_has_answer_form_id,form_question_has_answer_user_id | form_question_has_answer_form_id | 4 | | 797 | Using where | | 2 | DERIVED | p | ref | project_company_has_user_unique_key,project_company_has_user_user_id,project_company_has_user_company_id,project_company_has_user_project_id,project_company_has_user_garbage_collection | project_company_has_user_user_id | 4 | new_klarents.f.form_question_has_answer_user_id | 1 | Using where | | 2 | DERIVED | f2 | ref | form_project_id | form_project_id | 4 | | 15 | Using where | | 2 | DERIVED | c | eq_ref | PRIMARY | PRIMARY | 4 | new_klarents.p.project_company_has_user_company_id | 1 | Using where | | 2 | DERIVED | u | eq_ref | PRIMARY | PRIMARY | 4 | new_klarents.p.project_company_has_user_user_id | 1 | Using where; Using index | +----+-------------+-------+--------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------------+---------+----------------------------------------------------+------+------------------------------+ On the production server the information I have is as follows. Upon execution: +-------------+ | num_results | +-------------+ | 3 | +-------------+ 1 row in set (2 min 14.28 sec) Show profile: +--------------------------------+------------+ | Status | Duration | +--------------------------------+------------+ | starting | 0.000016 | | checking query cache for query | 0.000057 | | Opening tables | 0.004388 | | System lock | 0.000003 | | Table lock | 0.000036 | | init | 0.000030 | | optimizing | 0.000016 | | statistics | 0.000111 | | preparing | 0.000022 | | executing | 0.000004 | | Sorting result | 0.000002 | | Sending data | 136.213836 | | end | 0.000007 | | query end | 0.000002 | | freeing items | 0.004273 | | storing result in query cache | 0.000010 | | logging slow query | 0.000001 | | logging slow query | 0.000002 | | cleaning up | 0.000002 | +--------------------------------+------------+ On development the results are as follows. +-------------+ | num_results | +-------------+ | 3 | +-------------+ 1 row in set (0.08 sec) Again the profile for this query: +--------------------------------+----------+ | Status | Duration | +--------------------------------+----------+ | starting | 0.000022 | | checking query cache for query | 0.000148 | | Opening tables | 0.000025 | | System lock | 0.000008 | | Table lock | 0.000101 | | optimizing | 0.000035 | | statistics | 0.001019 | | preparing | 0.000047 | | executing | 0.000008 | | Sorting result | 0.000005 | | Sending data | 0.086565 | | init | 0.000015 | | optimizing | 0.000006 | | executing | 0.000020 | | end | 0.000004 | | query end | 0.000004 | | freeing items | 0.000028 | | storing result in query cache | 0.000005 | | removing tmp table | 0.000008 | | closing tables | 0.000008 | | logging slow query | 0.000002 | | cleaning up | 0.000005 | +--------------------------------+----------+ If i remove user and/or project innerjoins the query is reduced to 30s. Last bit of information I have: Mysqlserver and Apache are on the same box, there is only one box for production. Production output from top: before & after. top - 15:43:25 up 78 days, 12:11, 4 users, load average: 1.42, 0.99, 0.78 Tasks: 162 total, 2 running, 160 sleeping, 0 stopped, 0 zombie Cpu(s): 0.1%us, 50.4%sy, 0.0%ni, 49.5%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 4037868k total, 3772580k used, 265288k free, 243704k buffers Swap: 3905528k total, 265384k used, 3640144k free, 1207944k cached top - 15:44:31 up 78 days, 12:13, 4 users, load average: 1.94, 1.23, 0.87 Tasks: 160 total, 2 running, 157 sleeping, 0 stopped, 1 zombie Cpu(s): 0.2%us, 50.6%sy, 0.0%ni, 49.3%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 4037868k total, 3834300k used, 203568k free, 243736k buffers Swap: 3905528k total, 265384k used, 3640144k free, 1207804k cached But this isn't a good representation of production's normal status so here is a grab of it from today outside of executing the queries. top - 11:04:58 up 79 days, 7:33, 4 users, load average: 0.39, 0.58, 0.76 Tasks: 156 total, 1 running, 155 sleeping, 0 stopped, 0 zombie Cpu(s): 3.3%us, 2.8%sy, 0.0%ni, 93.9%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 4037868k total, 3676136k used, 361732k free, 271480k buffers Swap: 3905528k total, 268736k used, 3636792k free, 1063432k cached Development: This one doesn't change during or after. top - 15:47:07 up 110 days, 22:11, 7 users, load average: 0.17, 0.07, 0.06 Tasks: 210 total, 2 running, 208 sleeping, 0 stopped, 0 zombie Cpu(s): 0.1%us, 0.2%sy, 0.0%ni, 99.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 4111972k total, 1821100k used, 2290872k free, 238860k buffers Swap: 4183036k total, 66472k used, 4116564k free, 921072k cached

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• Implementation of ZipCrypto / Zip 2.0 encryption in java

  - by gomesla

  I'm trying o implement the zipcrypto / zip 2.0 encryption algoritm to deal with encrypted zip files as discussed in http://www.pkware.com/documents/casestudies/APPNOTE.TXT I believe I've followed the specs but just can't seem to get it working. I'm fairly sure the issue has to do with my interpretation of the crc algorithm. The documentation states CRC-32: (4 bytes) The CRC-32 algorithm was generously contributed by David Schwaderer and can be found in his excellent book "C Programmers Guide to NetBIOS" published by Howard W. Sams & Co. Inc. The 'magic number' for the CRC is 0xdebb20e3. The proper CRC pre and post conditioning is used, meaning that the CRC register is pre-conditioned with all ones (a starting value of 0xffffffff) and the value is post-conditioned by taking the one's complement of the CRC residual. Here is the snippet that I'm using for the crc32 public class PKZIPCRC32 { private static final int CRC32_POLYNOMIAL = 0xdebb20e3; private int crc = 0xffffffff; private int CRCTable[]; public PKZIPCRC32() { buildCRCTable(); } private void buildCRCTable() { int i, j; CRCTable = new int[256]; for (i = 0; i <= 255; i++) { crc = i; for (j = 8; j > 0; j--) if ((crc & 1) == 1) crc = (crc >>> 1) ^ CRC32_POLYNOMIAL; else crc >>>= 1; CRCTable[i] = crc; } } private int crc32(byte buffer[], int start, int count, int lastcrc) { int temp1, temp2; int i = start; crc = lastcrc; while (count-- != 0) { temp1 = crc >>> 8; temp2 = CRCTable[(crc ^ buffer[i++]) & 0xFF]; crc = temp1 ^ temp2; } return crc; } public int crc32(int crc, byte buffer) { return crc32(new byte[] { buffer }, 0, 1, crc); } } Below is my complete code. Can anyone see what I'm doing wrong. package org.apache.commons.compress.archivers.zip; import java.io.IOException; import java.io.InputStream; public class ZipCryptoInputStream extends InputStream { public class PKZIPCRC32 { private static final int CRC32_POLYNOMIAL = 0xdebb20e3; private int crc = 0xffffffff; private int CRCTable[]; public PKZIPCRC32() { buildCRCTable(); } private void buildCRCTable() { int i, j; CRCTable = new int[256]; for (i = 0; i <= 255; i++) { crc = i; for (j = 8; j > 0; j--) if ((crc & 1) == 1) crc = (crc >>> 1) ^ CRC32_POLYNOMIAL; else crc >>>= 1; CRCTable[i] = crc; } } private int crc32(byte buffer[], int start, int count, int lastcrc) { int temp1, temp2; int i = start; crc = lastcrc; while (count-- != 0) { temp1 = crc >>> 8; temp2 = CRCTable[(crc ^ buffer[i++]) & 0xFF]; crc = temp1 ^ temp2; } return crc; } public int crc32(int crc, byte buffer) { return crc32(new byte[] { buffer }, 0, 1, crc); } } private static final long ENCRYPTION_KEY_1 = 0x12345678; private static final long ENCRYPTION_KEY_2 = 0x23456789; private static final long ENCRYPTION_KEY_3 = 0x34567890; private InputStream baseInputStream = null; private final PKZIPCRC32 checksumEngine = new PKZIPCRC32(); private long[] keys = null; public ZipCryptoInputStream(ZipArchiveEntry zipEntry, InputStream inputStream, String passwd) throws Exception { baseInputStream = inputStream; // Decryption // ---------- // PKZIP encrypts the compressed data stream. Encrypted files must // be decrypted before they can be extracted. // // Each encrypted file has an extra 12 bytes stored at the start of // the data area defining the encryption header for that file. The // encryption header is originally set to random values, and then // itself encrypted, using three, 32-bit keys. The key values are // initialized using the supplied encryption password. After each byte // is encrypted, the keys are then updated using pseudo-random number // generation techniques in combination with the same CRC-32 algorithm // used in PKZIP and described elsewhere in this document. // // The following is the basic steps required to decrypt a file: // // 1) Initialize the three 32-bit keys with the password. // 2) Read and decrypt the 12-byte encryption header, further // initializing the encryption keys. // 3) Read and decrypt the compressed data stream using the // encryption keys. // Step 1 - Initializing the encryption keys // ----------------------------------------- // // Key(0) <- 305419896 // Key(1) <- 591751049 // Key(2) <- 878082192 // // loop for i <- 0 to length(password)-1 // update_keys(password(i)) // end loop // // Where update_keys() is defined as: // // update_keys(char): // Key(0) <- crc32(key(0),char) // Key(1) <- Key(1) + (Key(0) & 000000ffH) // Key(1) <- Key(1) * 134775813 + 1 // Key(2) <- crc32(key(2),key(1) >> 24) // end update_keys // // Where crc32(old_crc,char) is a routine that given a CRC value and a // character, returns an updated CRC value after applying the CRC-32 // algorithm described elsewhere in this document. keys = new long[] { ENCRYPTION_KEY_1, ENCRYPTION_KEY_2, ENCRYPTION_KEY_3 }; for (int i = 0; i < passwd.length(); ++i) { update_keys((byte) passwd.charAt(i)); } // Step 2 - Decrypting the encryption header // ----------------------------------------- // // The purpose of this step is to further initialize the encryption // keys, based on random data, to render a plaintext attack on the // data ineffective. // // Read the 12-byte encryption header into Buffer, in locations // Buffer(0) thru Buffer(11). // // loop for i <- 0 to 11 // C <- buffer(i) ^ decrypt_byte() // update_keys(C) // buffer(i) <- C // end loop // // Where decrypt_byte() is defined as: // // unsigned char decrypt_byte() // local unsigned short temp // temp <- Key(2) | 2 // decrypt_byte <- (temp * (temp ^ 1)) >> 8 // end decrypt_byte // // After the header is decrypted, the last 1 or 2 bytes in Buffer // should be the high-order word/byte of the CRC for the file being // decrypted, stored in Intel low-byte/high-byte order. Versions of // PKZIP prior to 2.0 used a 2 byte CRC check; a 1 byte CRC check is // used on versions after 2.0. This can be used to test if the password // supplied is correct or not. byte[] encryptionHeader = new byte[12]; baseInputStream.read(encryptionHeader); for (int i = 0; i < encryptionHeader.length; i++) { encryptionHeader[i] ^= decrypt_byte(); update_keys(encryptionHeader[i]); } } protected byte decrypt_byte() { byte temp = (byte) (keys[2] | 2); return (byte) ((temp * (temp ^ 1)) >> 8); } @Override public int read() throws IOException { // // Step 3 - Decrypting the compressed data stream // ---------------------------------------------- // // The compressed data stream can be decrypted as follows: // // loop until done // read a character into C // Temp <- C ^ decrypt_byte() // update_keys(temp) // output Temp // end loop int read = baseInputStream.read(); read ^= decrypt_byte(); update_keys((byte) read); return read; } private final void update_keys(byte ch) { keys[0] = checksumEngine.crc32((int) keys[0], ch); keys[1] = keys[1] + (byte) keys[0]; keys[1] = keys[1] * 134775813 + 1; keys[2] = checksumEngine.crc32((int) keys[2], (byte) (keys[1] >> 24)); } }

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• How to stop an IOException error using whilst using a combination of jython, pyro and ant?

  - by Kelso

  So the wonderful low down on this doozie of a problem: short version: We are building a distribution system for this item of software we're using. Basically we take out build artifact, store it on an ftp server which passes it to multiple clients which execute scripts to patch their servers. Long version: 1 distribution server multiple client servers software: jython 2.5.1, ant 1.8.0, pyro 3.10 The distribution server has an FTP server and a PYRO client running on it. Each client server has a PRYO server running on it. When the PYRO client is told to start the patch procedure then it reads a machine list which contains a list of all the client servers. Then connects to each of the PYRO servers one by one and execute the patch procedure. The procedure is: getPatch (gets the latest patch for that server), StopServer (stops the software that may or maynot be accessing what needs to be patched), Apply patch, StartServer. Each of the processes calls an ANT script that passes with some folder names and other config passes around. The fun part happens when you go to apply the patch. See below for error log. I had to remove the folder names because of NDA reasons. This is where it gets interesting. Running each section of the procedure individually. i.e. running getPatch, StopServer, etc. one at a time manually. This bug doesn't happen. Physically goign to the machine and running the processes it doesn't happen. Only when we call all 4 of the processes one after the other. It occurs during the ApplyPatch phase when an ANT replace script is called on multiple files. We think it might have something to do with the JVM keeping hold of the file for a split second or 2. however this is meant to have been patched according to the bug notes on ant. so in short: distribution server == jython == pyro connection == client server == jython == ant script Error Log: <*snip>\ant\deploy.xml:12: IOException in <*snip>\bin\startGs.sh - java.io.IOException:Failed to delete <*snip>\bin\rep4698373081723114968.tmp while trying to rename it. at org.apache.tools.ant.taskdefs.Replace.processFile(Replace.java:709) at org.apache.tools.ant.taskdefs.Replace.execute(Replace.java:548) at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291) at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.taskdefs.Sequential.execute(Sequential.java:68) at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291) at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.taskdefs.MacroInstance.execute(MacroInstance.java:398) at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291) at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.Target.execute(Target.java:390) at org.apache.tools.ant.Target.performTasks(Target.java:411) at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1360) at org.apache.tools.ant.helper.SingleCheckExecutor.executeTargets(SingleCheckExecutor.java:38) at org.apache.tools.ant.Project.executeTargets(Project.java:1212) at org.apache.tools.ant.taskdefs.Ant.execute(Ant.java:441) at org.apache.tools.ant.taskdefs.SubAnt.execute(SubAnt.java:302) at org.apache.tools.ant.taskdefs.SubAnt.execute(SubAnt.java:221) at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291) at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.Target.execute(Target.java:390) at org.apache.tools.ant.Target.performTasks(Target.java:411) at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1360) at org.apache.tools.ant.helper.SingleCheckExecutor.executeTargets(SingleCheckExecutor.java:38) at org.apache.tools.ant.Project.executeTargets(Project.java:1212) at org.apache.tools.ant.taskdefs.Ant.execute(Ant.java:441) at org.apache.tools.ant.Extaskdefs.SubAnt.execute(SubAnt.java:302) at org.apache.tools.ant.taskdefs.SubAnt.execute(SubAnt.java:221) at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291) at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.taskdefs.Sequential.execute(Sequential.java:68) at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291) at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.taskdefs.MacroInstance.execute(MacroInstance.java:398) at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291) at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.taskdefs.Sequential.execute(Sequential.java:68) at net.sf.antcontrib.logic.IfTask.execute(IfTask.java:197) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.TaskAdapter.execute(TaskAdapter.java:154) at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291) at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.Target.execute(Target.java:390) at org.apache.tools.ant.Target.performTasks(Target.java:411) at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1360) at org.apache.tools.ant.helper.SingleCheckExecutor.executeTargets(SingleCheckExecutor.java:38) at org.apache.tools.ant.Project.executeTargets(Project.java:1212) at org.apache.tools.ant.taskdefs.Ant.execute(Ant.java:441) at org.apache.tools.ant.taskdefs.SubAnt.execute(SubAnt.java:302) at org.apache.tools.ant.taskdefs.SubAnt.execute(SubAnt.java:221) at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.taskdefs.Sequential.execute(Sequential.java:68) at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) it at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.taskdefs.MacroInstance.execute(MacroInstance.java:398) at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.taskdefs.Sequential.execute(Sequential.java:68) at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.taskdefs.MacroInstance.execute(MacroInstance.java:398) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.taskdefs.Parallel$TaskRunnable.run(Parallel.java:433) at java.lang.Thread.run(Thread.java:619) Caused by: java.io.IOException: Failed to delete <*snip\bin\rep4698373081723114968.tmp while trying to rename it. at org.apache.tools.ant.util.FileUtils.rename(FileUtils.java:1248) at org.apache.tools.ant.taskdefs.Replace.processFile(Replace.java:702) ... 125 more Any help would be appreciated.

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• WCF timeout exception detailed investigation

  - by Jason Kealey

  We have an application that has a WCF service (*.svc) running on IIS7 and various clients querying the service. The server is running Win 2008 Server. The clients are running either Windows 2008 Server or Windows 2003 server. I am getting the following exception, which I have seen can in fact be related to a large number of potential WCF issues. System.TimeoutException: The request channel timed out while waiting for a reply after 00:00:59.9320000. Increase the timeout value passed to the call to Request or increase the SendTimeout value on the Binding. The time allotted to this operation may have been a portion of a longer timeout. ---> System.TimeoutException: The HTTP request to 'http://www.domain.com/WebServices/myservice.svc/gzip' has exceeded the allotted timeout of 00:01:00. The time allotted to this operation may have been a portion of a longer timeout. I have increased the timeout to 30min and the error still occurred. This tells me that something else is at play, because the quantity of data could never take 30min to upload or download. The error comes and goes. At the moment, it is more frequent. It does not seem to matter if I have 3 clients running simultaneously or 100, it still occurs once in a while. Most of the time, there are no timeouts but I still get a few per hour. The error comes from any of the methods that are invoked. One of these methods does not have parameters and returns a bit of data. Another takes in lots of data as a parameter but executes asynchronously. The errors always originate from the client and never reference any code on the server in the stack trace. It always ends with: at System.Net.HttpWebRequest.GetResponse() at System.ServiceModel.Channels.HttpChannelFactory.HttpRequestChannel.HttpChannelRequest.WaitForReply(TimeSpan timeout) On the server: I've tried (and currently have) the following binding settings: maxBufferSize="2147483647" maxReceivedMessageSize="2147483647" maxBufferPoolSize="2147483647" It does not seem to have an impact. I've tried (and currently have) the following throttling settings: <serviceThrottling maxConcurrentCalls="1500" maxConcurrentInstances="1500" maxConcurrentSessions="1500"/> It does not seem to have an impact. I currently have the following settings for the WCF service. [ServiceBehavior(InstanceContextMode = InstanceContextMode.Single, ConcurrencyMode = ConcurrencyMode.Single)] I ran with ConcurrencyMode.Multiple for a while, and the error still occurred. I've tried restarting IIS, restarting my underlying SQL Server, restarting the machine. All of these don't seem to have an impact. I've tried disabling the Windows firewall. It does not seem to have an impact. On the client, I have these settings: maxReceivedMessageSize="2147483647" <system.net> <connectionManagement> <add address="*" maxconnection="16"/> </connectionManagement> </system.net> My client closes its connections: var client = new MyClient(); try { return client.GetConfigurationOptions(); } finally { client.Close(); } I have changed the registry settings to allow more outgoing connections: MaxConnectionsPerServer=24, MaxConnectionsPer1_0Server=32. I have now just recently tried SvcTraceViewer.exe. I managed to catch one exception on the client end. I see that its duration is 1 minute. Looking at the server side trace, I can see that the server is not aware of this exception. The maximum duration I can see is 10 seconds. I have looked at active database connections using exec sp_who on the server. I only have a few (2-3). I have looked at TCP connections from one client using TCPview. It usually is around 2-3 and I have seen up to 5 or 6. Simply put, I am stumped. I have tried everything I could find, and must be missing something very simple that a WCF expert would be able to see. It is my gut feeling that something is blocking my clients at the low-level (TCP), before the server actually receives the message and/or that something is queuing the messages at the server level and never letting them process. If you have any performance counters I should look at, please let me know. (please indicate what values are bad, as some of these counters are hard to decypher). Also, how could I log the WCF message size? Finally, are there any tools our there that would allow me to test how many connections I can establish between my client and server (independently from my application) Thanks for your time! Extra information added June 20th: My WCF application does something similar to the following. while (true) { Step1GetConfigurationSettingsFromServerViaWCF(); // can change between calls Step2GetWorkUnitFromServerViaWCF(); DoWorkLocally(); // takes 5-15minutes. Step3SendBackResultsToServerViaWCF(); } Using WireShark, I did see that when the error occurs, I have a five TCP retransmissions followed by a TCP reset later on. My guess is the RST is coming from WCF killing the connection. The exception report I get is from Step3 timing out. I discovered this by looking at the tcp stream "tcp.stream eq 192". I then expanded my filter to "tcp.stream eq 192 and http and http.request.method eq POST" and saw 6 POSTs during this stream. This seemed odd, so I checked with another stream such as tcp.stream eq 100. I had three POSTs, which seems a bit more normal because I am doing three calls. However, I do close my connection after every WCF call, so I would have expected one call per stream (but I don't know much about TCP). Investigating a bit more, I dumped the http packet load to disk to look at what these six calls where. 1) Step3 2) Step1 3) Step2 4) Step3 - corrupted 5) Step1 6) Step2 My guess is two concurrent clients are using the same connection, that is why I saw duplicates. However, I still have a few more issues that I can't comprehend: a) Why is the packet corrupted? Random network fluke - maybe? The load is gzipped using this sample code: http://msdn.microsoft.com/en-us/library/ms751458.aspx - Could the code be buggy once in a while when used concurrently? I should test without the gzip library. b) Why would I see step 1 & step 2 running AFTER the corrupted operation timed out? It seems to me as if these operations should not have occurred. Maybe I am not looking at the right stream because my understanding of TCP is flawed. I have other streams that occur at the same time. I should investigate other streams - a quick glance at streams 190-194 show that the Step3 POST have proper payload data (not corrupted). Pushing me to look at the gzip library again.

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• Out of memory exception during scrolling of listview

  - by user1761316

  I am using facebook data like postedpicture,profile picture,name,message in my listview.I am getting an OOM error while doing fast scrolling of listview. I am also having scrollviewlistener in my application that loads more data when the scrollbar reaches the bottom of the screen.I just want to know whether I need to change anything in this class. imageLoader.DisplayImage(postimage.get(position).replace(" ", "%20"), postimg) ; I am using the above line to call the method in this imageloader class to set the bitmap to imageview. Here is my imageloader class import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.InputStream; import java.io.OutputStream; import java.net.HttpURLConnection; import java.net.URL; import java.util.Collections; import java.util.Map; import java.util.Stack; import java.util.WeakHashMap; import com.stellent.beerbro.Wall; import android.app.Activity; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Bitmap.Config; import android.graphics.BitmapFactory; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.PorterDuff.Mode; import android.graphics.PorterDuffXfermode; import android.graphics.Rect; import android.graphics.RectF; import android.graphics.drawable.BitmapDrawable; import android.util.Log; import android.widget.ImageView; public class ImageLoader { MemoryCache memoryCache=new MemoryCache(); FileCache fileCache; private Map<ImageView, String> imageViews=Collections.synchronizedMap(new WeakHashMap<ImageView, String>()); public ImageLoader(Context context){ //Make the background thead low priority. This way it will not affect the UI performance photoLoaderThread.setPriority(Thread.NORM_PRIORITY-1); fileCache=new FileCache(context); } // final int stub_id=R.drawable.stub; public void DisplayImage(String url,ImageView imageView) { imageViews.put(imageView, url); System.gc(); // Bitmap bitmap=createScaledBitmap(memoryCache.get(url), 100,100,0); Bitmap bitmap=memoryCache.get(url); // Bitmap bitmaps=bitmap.createScaledBitmap(bitmap, 0, 100, 100); if(bitmap!=null) { imageView.setBackgroundDrawable(new BitmapDrawable(bitmap)); // imageView.setImageBitmap(getRoundedCornerBitmap( bitmap, 10,70,70)); // imageView.setImageBitmap(bitmap); // Log.v("first", "first"); } else { queuePhoto(url, imageView); // Log.v("second", "second"); } } private Bitmap createScaledBitmap(Bitmap bitmap, int i, int j, int k) { // TODO Auto-generated method stub return null; } private void queuePhoto(String url, ImageView imageView) { //This ImageView may be used for other images before. So there may be some old tasks in the queue. We need to discard them. photosQueue.Clean(imageView); PhotoToLoad p=new PhotoToLoad(url, imageView); synchronized(photosQueue.photosToLoad){ photosQueue.photosToLoad.push(p); photosQueue.photosToLoad.notifyAll(); } //start thread if it's not started yet if(photoLoaderThread.getState()==Thread.State.NEW) photoLoaderThread.start(); } public Bitmap getBitmap(String url) { File f=fileCache.getFile(url); //from SD cache Bitmap b = decodeFile(f); if(b!=null) return b; //from web try { Bitmap bitmap=null; URL imageUrl = new URL(url); HttpURLConnection conn = (HttpURLConnection)imageUrl.openConnection(); conn.setConnectTimeout(30000); conn.setReadTimeout(30000); InputStream is=conn.getInputStream(); OutputStream os = new FileOutputStream(f); Utils.CopyStream(is, os); os.close(); bitmap = decodeFile(f); return bitmap; } catch (Exception ex){ ex.printStackTrace(); return null; } }//Lalit //decodes image and scales it to reduce memory consumption private Bitmap decodeFile(File f){ try { //decode image size BitmapFactory.Options o = new BitmapFactory.Options(); o.inJustDecodeBounds = true; BitmapFactory.decodeStream(new FileInputStream(f),null,o); //Find the correct scale value. It should be the power of 2. final int REQUIRED_SIZE=Wall.width; final int REQUIRED_SIZE1=Wall.height; // final int REQUIRED_SIZE=250; // int width_tmp=o.outWidth, height_tmp=o.outHeight; int scale=1; // while(o.outWidth/scale/2>=REQUIRED_SIZE && o.outHeight/scale/2>=REQUIRED_SIZE) //// scale*=2; while(true){ if(width_tmp/2<REQUIRED_SIZE && height_tmp/2<REQUIRED_SIZE1) break; width_tmp/=2; height_tmp/=2; scale*=2; } //decode with inSampleSize BitmapFactory.Options o2 = new BitmapFactory.Options(); o2.inSampleSize=scale; // o2.inSampleSize=2; return BitmapFactory.decodeStream(new FileInputStream(f), null, o2); } catch (FileNotFoundException e) {} return null; } //Task for the queue private class PhotoToLoad { public String url; public ImageView imageView; public PhotoToLoad(String u, ImageView i){ url=u; imageView=i; } } PhotosQueue photosQueue=new PhotosQueue(); public void stopThread() { photoLoaderThread.interrupt(); } //stores list of photos to download class PhotosQueue { private Stack<PhotoToLoad> photosToLoad=new Stack<PhotoToLoad>(); //removes all instances of this ImageView public void Clean(ImageView image) { for(int j=0 ;j<photosToLoad.size();){ if(photosToLoad.get(j).imageView==image) photosToLoad.remove(j); else ++j; } } } class PhotosLoader extends Thread { public void run() { try { while(true) { //thread waits until there are any images to load in the queue if(photosQueue.photosToLoad.size()==0) synchronized(photosQueue.photosToLoad){ photosQueue.photosToLoad.wait(); } if(photosQueue.photosToLoad.size()!=0) { PhotoToLoad photoToLoad; synchronized(photosQueue.photosToLoad){ photoToLoad=photosQueue.photosToLoad.pop(); } Bitmap bmp=getBitmap(photoToLoad.url); memoryCache.put(photoToLoad.url, bmp); String tag=imageViews.get(photoToLoad.imageView); if(tag!=null && tag.equals(photoToLoad.url)){ BitmapDisplayer bd=new BitmapDisplayer(bmp, photoToLoad.imageView); Activity a=(Activity)photoToLoad.imageView.getContext(); a.runOnUiThread(bd); } } if(Thread.interrupted()) break; } } catch (InterruptedException e) { //allow thread to exit } } } PhotosLoader photoLoaderThread=new PhotosLoader(); //Used to display bitmap in the UI thread class BitmapDisplayer implements Runnable { Bitmap bitmap; ImageView imageView; public BitmapDisplayer(Bitmap b, ImageView i){bitmap=b;imageView=i;} public void run() { if(bitmap!=null) imageView.setBackgroundDrawable(new BitmapDrawable(bitmap)); } } public void clearCache() { memoryCache.clear(); fileCache.clear(); } public static Bitmap getRoundedCornerBitmap(Bitmap bitmap, int pixels,int width,int height) { Bitmap output = Bitmap.createBitmap(width,height, Config.ARGB_8888); Canvas canvas = new Canvas(output); final int color = 0xff424242; final Paint paint = new Paint(); final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight()); final RectF rectF = new RectF(rect); final float roundPx = pixels; paint.setAntiAlias(true); canvas.drawARGB(0, 0, 0, 0); paint.setColor(color); canvas.drawRoundRect(rectF, roundPx, roundPx, paint); paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN)); canvas.drawBitmap(bitmap, rect, rect, paint); return output; } }

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• How do I do event handling in php with html?

  - by TheAmazingKnight

  I am constructing a simple quiz using html and php. The problem I'm having is that I'm not sure how to do event handlers since it's my first time doing php. Simply, the user click on Take Quiz and it brings up the quiz, then submit the quiz using the same page and show score results. The quiz was written in HTML as shown below: HTML CODE: <section> <h1 id="theme"><span class="initial">Q</span>uiz</h1> <div id="message">Why not go ahead and take the quiz to test your knowledge based on what you've learned in Smartphone Photography. There are only 5 questions surrounding the content of this site. Good Luck! :) <br/> <button type="button" name="name" onclick="takeQuiz()">Take Quiz!</button> </div> </section> </div> <form action="grade.php" method="post" id="quiz"> <!--Question 1--> <h3>1. How many percent of modern camera phones use CMOS?</h3> <div> <input type="radio" name="question-1-answers" id="question-1-answers-A" value="A" /> <label for="question-1-answers-A">A) 20%</label> <br/> <input type="radio" name="question-1-answers" id="question-1-answers-B" value="B" /> <label for="question-1-answers-B">B) 80%</label> <br/> <input type="radio" name="question-1-answers" id="question-1-answers-C" value="C" /> <label for="question-1-answers-C">C) 50%</label> <br/> <input type="radio" name="question-1-answers" id="question-1-answers-D" value="D" /> <label for="question-1-answers-D">D) 90%</label> </div> <!--Question 2--> <h3>2. Which type of camera setting(s) is best for greater control and flexibility in terms of focusing on a subject?</h3> <div> <input type="radio" name="question-2-answers" id="question-2-answers-A" value="A" /> <label for="question-2-answers-A">A) Manual Focus</label> <br/> <input type="radio" name="question-2-answers" id="question-2-answers-B" value="B" /> <label for="question-2-answers-B">B) Auto Focus</label> <br/> <input type="radio" name="question-2-answers" id="question-2-answers-C" value="C" /> <label for="question-2-answers-C">C) Both A and B</label> <br/> <input type="radio" name="question-2-answers" id="question-2-answers-D" value="D" /> <label for="question-2-answers-D">D) Neither</label> </div> <!--Question 3--> <h3>3. What are the three properties included in an exposure triangle?</h3> <div> <input type="radio" name="question-3-answers" id="question-3-answers-A" value="A" /> <label for="question-3-answers-A">A) White Balance, ISO, Low Light</label> <br/> <input type="radio" name="question-3-answers" id="question-3-answers-B" value="B" /> <label for="question-3-answers-B">B) Shutter Speed, Exposure, ISO</label> <br/> <input type="radio" name="question-3-answers" id="question-3-answers-C" value="C" /> <label for="question-3-answers-C">C) Aperture, ISO, Exposure</label> <br/> <input type="radio" name="question-3-answers" id="question-3-answers-D" value="D" /> <label for="question-3-answers-D">D) ISO, Aperture, Shutter Speed</label> </div> <!--Question 4--> <h3>4. The higher the ISO, the more noise it produces in an image.</h3> <div> <input type="radio" name="question-4-answers" id="question-4-answers-A" value="A" /> <label for="question-4-answers-A">A) True</label> <br/> <input type="radio" name="question-4-answers" id="question-4-answers-B" value="B" /> <label for="question-4-answers-B">B) False</label> </div> <!--Question 5--> <h3>5. What is the name of the smartphone you've seen all over this site?</h3> <div> <input type="radio" name="question-5-answers" id="question-5-answers-A" value="A" /> <label for="question-5-answers-A">A) Nokia Pureview 808</label> <br/> <input type="radio" name="question-5-answers" id="question-5-answers-B" value="B" /> <label for="question-5-answers-B">B) Nokia Lumia 1020</label> <br/> <input type="radio" name="question-5-answers" id="question-5-answers-C" value="C" /> <label for="question-5-answers-C">C) Nokia Lumia 925</label> <br/> <input type="radio" name="question-5-answers" id="question-5-answers-D" value="D" /> <label for="question-5-answers-D">D) Nokia Lumia 920</label> </div> <input type="submit" value="Submit Quiz" /> </form> Then I have a php file named grade.php which will print the results of the quiz grade. PHP CODE: <?php // create variables linking the questions' answers from the form $answer1 = $_POST['question-1-answers']; $answer2 = $_POST['question-2-answers']; $answer3 = $_POST['question-3-answers']; $answer4 = $_POST['question-4-answers']; $answer5 = $_POST['question-5-answers']; $totalCorrect = 0; // Set up if-statements and determine the correct answers to be POSTed if($answer1 == "D") { $totalCorrect++; } if($answer2 == "A") { $totalCorrect++; } if($answer3 == "D") { $totalCorrect++; } if($answer4 == "A") { $totalCorrect++; } if($answer5 == "B") { $totalCorrect++; } //display the results echo "<div id='results'>$totalCorrect / 5 correct</div>"; ?>

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• Marshalling to a native library in C#

  - by Daniel Baulig

  I'm having trouble calling functions of a native library from within managed C# code. I am developing for the 3.5 compact framework (Windows Mobile 6.x) just in case this would make any difference. I am working with the waveIn* functions from coredll.dll (these are in winmm.dll in regular Windows I believe). This is what I came up with: // namespace winmm; class winmm [StructLayout(LayoutKind.Sequential)] public struct WAVEFORMAT { public ushort wFormatTag; public ushort nChannels; public uint nSamplesPerSec; public uint nAvgBytesPerSec; public ushort nBlockAlign; public ushort wBitsPerSample; public ushort cbSize; } [StructLayout(LayoutKind.Sequential)] public struct WAVEHDR { public IntPtr lpData; public uint dwBufferLength; public uint dwBytesRecorded; public IntPtr dwUser; public uint dwFlags; public uint dwLoops; public IntPtr lpNext; public IntPtr reserved; } public delegate void AudioRecordingDelegate(IntPtr deviceHandle, uint message, IntPtr instance, ref WAVEHDR wavehdr, IntPtr reserved2); [DllImport("coredll.dll")] public static extern int waveInAddBuffer(IntPtr hWaveIn, ref WAVEHDR lpWaveHdr, uint cWaveHdrSize); [DllImport("coredll.dll")] public static extern int waveInPrepareHeader(IntPtr hWaveIn, ref WAVEHDR lpWaveHdr, uint Size); [DllImport("coredll.dll")] public static extern int waveInStart(IntPtr hWaveIn); // some other class private WinMM.WinMM.AudioRecordingDelegate waveIn; private IntPtr handle; private uint bufferLength; private void setupBuffer() { byte[] buffer = new byte[bufferLength]; GCHandle bufferPin = GCHandle.Alloc(buffer, GCHandleType.Pinned); WinMM.WinMM.WAVEHDR hdr = new WinMM.WinMM.WAVEHDR(); hdr.lpData = bufferPin.AddrOfPinnedObject(); hdr.dwBufferLength = this.bufferLength; hdr.dwFlags = 0; int i = WinMM.WinMM.waveInPrepareHeader(this.handle, ref hdr, Convert.ToUInt32(Marshal.SizeOf(hdr))); if (i != WinMM.WinMM.MMSYSERR_NOERROR) { this.Text = "Error: waveInPrepare"; return; } i = WinMM.WinMM.waveInAddBuffer(this.handle, ref hdr, Convert.ToUInt32(Marshal.SizeOf(hdr))); if (i != WinMM.WinMM.MMSYSERR_NOERROR) { this.Text = "Error: waveInAddrBuffer"; return; } } private void setupWaveIn() { WinMM.WinMM.WAVEFORMAT format = new WinMM.WinMM.WAVEFORMAT(); format.wFormatTag = WinMM.WinMM.WAVE_FORMAT_PCM; format.nChannels = 1; format.nSamplesPerSec = 8000; format.wBitsPerSample = 8; format.nBlockAlign = Convert.ToUInt16(format.nChannels * format.wBitsPerSample); format.nAvgBytesPerSec = format.nSamplesPerSec * format.nBlockAlign; this.bufferLength = format.nAvgBytesPerSec; format.cbSize = 0; int i = WinMM.WinMM.waveInOpen(out this.handle, WinMM.WinMM.WAVE_MAPPER, ref format, Marshal.GetFunctionPointerForDelegate(waveIn), 0, WinMM.WinMM.CALLBACK_FUNCTION); if (i != WinMM.WinMM.MMSYSERR_NOERROR) { this.Text = "Error: waveInOpen"; return; } setupBuffer(); WinMM.WinMM.waveInStart(this.handle); } I read alot about marshalling the last few days, nevertheless I do not get this code working. When my callback function is called (waveIn) when the buffer is full, the hdr structure passed back in wavehdr is obviously corrupted. Here is an examlpe of how the structure looks like at that point: - wavehdr {WinMM.WinMM.WAVEHDR} WinMM.WinMM.WAVEHDR dwBufferLength 0x19904c00 uint dwBytesRecorded 0x0000fa00 uint dwFlags 0x00000003 uint dwLoops 0x1990f6a4 uint + dwUser 0x00000000 System.IntPtr + lpData 0x00000000 System.IntPtr + lpNext 0x00000000 System.IntPtr + reserved 0x7c07c9a0 System.IntPtr This obiously is not what I expected to get passed. I am clearly concerned about the order of the fields in the view. I do not know if Visual Studio .NET cares about actual memory order when displaying the record in the "local"-view, but they are obviously not displayed in the order I speciefied in the struct. Then theres no data pointer and the bufferLength field is far to high. Interestingly the bytesRecorded field is exactly 64000 - bufferLength and bytesRecorded I'd expect both to be 64000 though. I do not know what exactly is going wrong, maybe someone can help me out on this. I'm an absolute noob to managed code programming and marshalling so please don't be too harsh to me for all the stupid things I've propably done. Oh here's the C code definition for WAVEHDR which I found here, I believe I might have done something wrong in the C# struct definition: /* wave data block header */ typedef struct wavehdr_tag { LPSTR lpData; /* pointer to locked data buffer */ DWORD dwBufferLength; /* length of data buffer */ DWORD dwBytesRecorded; /* used for input only */ DWORD_PTR dwUser; /* for client's use */ DWORD dwFlags; /* assorted flags (see defines) */ DWORD dwLoops; /* loop control counter */ struct wavehdr_tag FAR *lpNext; /* reserved for driver */ DWORD_PTR reserved; /* reserved for driver */ } WAVEHDR, *PWAVEHDR, NEAR *NPWAVEHDR, FAR *LPWAVEHDR; If you are used to work with all those low level tools like pointer-arithmetic, casts, etc starting writing managed code is a pain in the ass. It's like trying to learn how to swim with your hands tied on your back. Some things I tried (to no effect): .NET compact framework does not seem to support the Pack = 2^x directive in [StructLayout]. I tried [StructLayout(LayoutKind.Explicit)] and used 4 bytes and 8 bytes alignment. 4 bytes alignmentgave me the same result as the above code and 8 bytes alignment only made things worse - but that's what I expected. Interestingly if I move the code from setupBuffer into the setupWaveIn and do not declare the GCHandle in the context of the class but in a local context of setupWaveIn the struct returned by the callback function does not seem to be corrupted. I am not sure however why this is the case and how I can use this knowledge to fix my code. I'd really appreciate any good links on marshalling, calling unmanaged code from C#, etc. Then I'd be very happy if someone could point out my mistakes. What am I doing wrong? Why do I not get what I'd expect.

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• Authoritative sources about Database vs. Flatfile decision

  - by FastAl

  <tldr>looking for a reference to a book or other undeniably authoritative source that gives reasons when you should choose a database vs. when you should choose other storage methods. I have provided an un-authoritative list of reasons about 2/3 of the way down this post.</tldr> I have a situation at my company where a database is being used where it would be better to use another solution (in this case, an auto-generated piece of source code that contains a static lookup table, searched by binary sort). Normally, a database would be an OK solution even though the problem does not require a database, e.g, none of the elements of ACID are needed, as it is read-only data, updated about every 3-5 years (also requiring other sourcecode changes), and fits in memory, and can be keyed into via binary search (a tad faster than db, but speed is not an issue). The problem is that this code runs on our enterprise server, but is shared with several PC platforms (some disconnected, some use a central DB, etc.), and parts of it are managed by multiple programming units, parts by the DBAs, parts even by mathematicians in another department, etc. These hit their own platform’s version of their databases (containing their own copy of the static data). What happens is that every implementation, every little change, something different goes wrong. There are many other issues as well. I can’t even use a flatfile, because one mode of running on our enterprise server does not have permission to read files (only databases, and of course, its own literal storage, e.g., in-source table). Of course, other parts of the system use databases in proper, less obscure manners; there is no problem with those parts. So why don’t we just change it? I don’t have administrative ability to force a change. But I’m affected because sometimes I have to help fix the problems, but mostly because it causes outages and tons of extra IT time by other programmers and d*mmit that makes me mad! The reason neither management, nor the designers of the system, can see the problem is that they propose a solution that won’t work: increase communication; implement more safeguards and standards; etc. But every time, in a different part of the already-pared-down but still multi-step processes, a few different diligent, hard-working, top performing IT personnel make a unique subtle error that causes it to fail, sometimes after the last round of testing! And in general these are not single-person failures, but understandable miscommunications. And communication at our company is actually better than most. People just don't think that's the case because they haven't dug into the matter. However, I have it on very good word from somebody with extensive formal study of sociology and psychology that the relatively small amount of less-than-proper database usage in this gigantic cross-platform multi-source, multi-language project is bureaucratically un-maintainable. Impossible. No chance. At least with Human Beings in the loop, and it can’t be automated. In addition, the management and developers who could change this, though intelligent and capable, don’t understand the rigidity of this ‘how humans are’ issue, and are not convincible on the matter. The reason putting the static data in sourcecode will solve the problem is, although the solution is less sexy than a database, it would function with no technical drawbacks; and since the sharing of sourcecode already works very well, you basically erase any database-related effort from this section of the project, along with all the drawbacks of it that are causing problems. OK, that’s the background, for the curious. I won’t be able to convince management that this is an unfixable sociological problem, and that the real solution is coding around these limits of human nature, just as you would code around a bug in a 3rd party component that you can’t change. So what I have to do is exploit the unsuitableness of the database solution, and not do it using logic, but rather authority. I am aware of many reasons, and posts on this site giving reasons for one over the other; I’m not looking for lists of reasons like these (although you can add a comment if I've miss a doozy): WHY USE A DATABASE? instead of flatfile/other DB vs. file: if you need... Random Read / Transparent search optimization Advanced / varied / customizable Searching and sorting capabilities Transaction/rollback Locks, semaphores Concurrency control / Shared users Security 1-many/m-m is easier Easy modification Scalability Load Balancing Random updates / inserts / deletes Advanced query Administrative control of design, etc. SQL / learning curve Debugging / Logging Centralized / Live Backup capabilities Cached queries / dvlp & cache execution plans Interleaved update/read Referential integrity, avoid redundant/missing/corrupt/out-of-sync data Reporting (from on olap or oltp db) / turnkey generation tools [Disadvantages:] Important to get right the first time - professional design - but only b/c it's meant to last s/w & h/w cost Usu. over a network, speed issue (best vs. best design vs. local=even then a separate process req's marshalling/netwk layers/inter-p comm) indicies and query processing can stand in the way of simple processing (vs. flatfile) WHY USE FLATFILE: If you only need... Sequential Row processing only Limited usage append only (no reading, no master key/update) Only Update the record you're reading (fixed length recs only) Too big to fit into memory If Local disk / read-ahead network connection Portability / small system Email / cut & Paste / store as document by novice - simple format Low design learning curve but high cost later WHY USE IN-MEMORY/TABLE (tables, arrays, etc.): if you need... Processing a single db/ff record that was imported Known size of data Static data if hardcoding the table Narrow, unchanging use (e.g., one program or proc) -includes a class that will be shared, but encapsulates its data manipulation Extreme speed needed / high transaction frequency Random access - but search is dependent on implementation Following are some other posts about the topic: http://stackoverflow.com/questions/1499239/database-vs-flat-text-file-what-are-some-technical-reasons-for-choosing-one-over http://stackoverflow.com/questions/332825/are-flat-file-databases-any-good http://stackoverflow.com/questions/2356851/database-vs-flat-files http://stackoverflow.com/questions/514455/databases-vs-plain-text/514530 What I’d like to know is if anybody could recommend a hard, authoritative source containing these reasons. I’m looking for a paper book I can buy, or a reputable website with whitepapers about the issue (e.g., Microsoft, IBM), not counting the user-generated content on those sites. This will have a greater change to elicit a change that I’m looking for: less wasted programmer time, and more reliable programs. Thanks very much for your help. You win a prize for reading such a large post!

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• How to find an entry-level job after you already have a graduate degree?

  - by Uri

  Note: I asked this question in early 2009. A couple of months later, I found a great job. I've previously updated this question with some tips for whoever ends up in a similar situation, and now cleaned it up a little for the benefit of the fresh batch of graduates. Original post: In my early 20s I abandoned a great C++ development career path in a major company to go to graduate school and get a research masters (3 years). I did another year in industrial research, and then moved to the US to attend graduate school again, getting another masters and a Ph.D in software engineering from a top school (another 6 years down the drain). I was coding the whole way throughout my degrees (core Java and Eclipse plug-ins) and working on research related to software engineering (usability of APIs). I ended up graduating the year of the recession, with a son on the way and the prospects of no healthcare. Academic jobs and industrial research jobs are quite scarce. Initially, I was naive, thinking that with my background, I could easily find a coding job. Big mistake. It turns out that I'm in a complicated position. Entry level positions are usually offered to college undergraduates. I attended my school's career fairs, but you could immediately see signs of Ph.D. aversion and overqualification issues. Some of the recruiters I spoke with explicitly told me that they wanted 20 year olds with clean slates, and some were looking for interns since they are in various forms of hiring freezes. I managed to get a couple of interviews from these career fairs and through recruiters. However, since I've been out of school for a long time and programming primarily in Java, I am also no longer proficient in C/C++ and the usual range of college-level interview questions that everyone uses. I had no problems with this when I was 19 and interviewing for my first job since a lot of what you do in C is manipulate pointers and I was coding C++ for fun and for school. Later I was routinely doing pointer manipulation on the job, and during my first masters taught college courses with data structures and C++. But even though I remember many properties of C++ well, it's been close to ten years since I regularly used C++ and pointers. As a Java developer I rarely had to work at this level, but experience in OOD and in writing good maintainable code is meaningless for C++ interviews. Reading books as a refresh and looking at sample code did not do the trick. I also looked at mid-to-senior level Java positions, but most of them focused on J2EE APIs rather than on core Java and required a certain number of years in industrial positions. Coding research tools and prior C++ experience doesn't count. So that sends me back to entry-level jobs that are posted through job-boards, and these are not common (mostly they are Monster junk), and small companies are even less likely to answer a Ph.D. compared to the giants who participate in top-10 career fairs. Even worse, in many companies initial screening is done by HR folks who really don't want to deal with anything anomalous like a Ph.D. Any tips on how I should approach this intractable position? For example, what should I write in cover letters? Note that while immigration is not an issue for me, I cannot go freelance as I need the benefits (and in particular group health insurance). During my studies I had no time to contribute to open-source projects or maintain a popular blog, so even if I invested in that now there would be no immediate benefit. Updates: In the two months after posting this I received several offers to work as a core Java developer in the financial industry and accepted one from a firm where I am working to this day. For those who find themselves in similar situations, here are my tips: Give up on trying to find an entry level positions. You can't undo time. Accept the fact that there is Ph.D. discrimination in the job market (some might say rightfully so). It is legal to discriminate based on education. No point fighting it. The most important tip is to focus on the language you are comfortable with. The sad truth about programming in a particular language is that it is not like riding a bike. If you haven't used a language in the last few years, and can't actually apply it routinely (not just as a refresher) before you start your search, it is going to be very difficult to do well in an interview. Now that I'm interviewing others, I routinely see it in folks with a mixed C++/Java background. We maintain "a shadow" of the old language but end up with a weird mix that makes it hard to interview on either. Entry-level folks are at an advantage here since they usually have one language. Memory can help you do great in a screening interview, but without recent day-to-day experience, code tests will be difficult. Despite the supposed relation, core Java programming and J2EE programming are two different things with different skillsets. If you come from academia, you likely have very little J2EE experience and may find it hard to get accepted for a J2EE job. J2EE jobs seem to have a larger list of acronyms in their requirements. In addition, from interviewing J2EE developers it seems that for many there is a focus on mastering specific APIs and architectures, whereas core Java development tends to be secondary. In the same way that I can no longer manipulate pointers well, a J2EE developer may have difficulties doing low level Java manipulation. This puts you at a relative advantage in competing for core Java jobs! If you are able to work for startups (in terms of family life and stability) or migrate to startup-rich areas such as the west coast, you can find many exciting opportunities where advanced degrees are a benefit. I've since been approached by several startups, although I had to decline. Work through a recruiter if possible. They have direct contacts with the hiring parties, allowing you to "stand out". It is better to get a clear yes/no confirmation from a recruiter on whether a company might be interested in interviewing you, than it is to send your resume and hope that someone will ever see it. Recruiters are also a great way of bypassing HR. However, also beware of recruiters. They have a vested interest and will go to various shady practices and pressure tactics. To find a good recruiter, talk to a friend who declined a job offer he got through a recruiter. A good recruiter, to me, is measured in how they handle that. Interview for the jobs that require your core strength. If you're rusty or entirely unfamiliar with a technology around which the job revolves, you're probably not a good match. Yes, you probably have the talent to master them, but most companies would want "instant gratification". I got my offers from companies that wanted core Java developer. I didn't do well on places that wanted advance C++ because I am too rusty and not up to date on recent libraries. I also didn't hear from companies that wanted lots of J2EE experience, and that's ok. Finding companies that want core Java without web is harder, but exists in specific industries (e.g., finance, defense). This requires a lot more legwork in terms of search, but these jobs do exist. There are different interview styles. Some companies focus on puzzles, some companies focus on algorithms, and some companies focus on design and coding skills. I had the most success in places where the questions were the most related to the function I would have been performing. Pick companies accordingly as well.

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• How do I prove I should put a table of values in source code instead of a database table?

  - by FastAl

  <tldr>looking for a reference to a book or other undeniably authoritative source that gives reasons when you should choose a database vs. when you should choose other storage methods. I have provided an un-authoritative list of reasons about 2/3 of the way down this post.</tldr> I have a situation at my company where a database is being used where it would be better to use another solution (in this case, an auto-generated piece of source code that contains a static lookup table, searched by binary sort). Normally, a database would be an OK solution even though the problem does not require a database, e.g, none of the elements of ACID are needed, as it is read-only data, updated about every 3-5 years (also requiring other sourcecode changes), and fits in memory, and can be keyed into via binary search (a tad faster than db, but speed is not an issue). The problem is that this code runs on our enterprise server, but is shared with several PC platforms (some disconnected, some use a central DB, etc.), and parts of it are managed by multiple programming units, parts by the DBAs, parts even by mathematicians in another department, etc. These hit their own platform’s version of their databases (containing their own copy of the static data). What happens is that every implementation, every little change, something different goes wrong. There are many other issues as well. I can’t even use a flatfile, because one mode of running on our enterprise server does not have permission to read files (only databases, and of course, its own literal storage, e.g., in-source table). Of course, other parts of the system use databases in proper, less obscure manners; there is no problem with those parts. So why don’t we just change it? I don’t have administrative ability to force a change. But I’m affected because sometimes I have to help fix the problems, but mostly because it causes outages and tons of extra IT time by other programmers and d*mmit that makes me mad! The reason neither management, nor the designers of the system, can see the problem is that they propose a solution that won’t work: increase communication; implement more safeguards and standards; etc. But every time, in a different part of the already-pared-down but still multi-step processes, a few different diligent, hard-working, top performing IT personnel make a unique subtle error that causes it to fail, sometimes after the last round of testing! And in general these are not single-person failures, but understandable miscommunications. And communication at our company is actually better than most. People just don't think that's the case because they haven't dug into the matter. However, I have it on very good word from somebody with extensive formal study of sociology and psychology that the relatively small amount of less-than-proper database usage in this gigantic cross-platform multi-source, multi-language project is bureaucratically un-maintainable. Impossible. No chance. At least with Human Beings in the loop, and it can’t be automated. In addition, the management and developers who could change this, though intelligent and capable, don’t understand the rigidity of this ‘how humans are’ issue, and are not convincible on the matter. The reason putting the static data in sourcecode will solve the problem is, although the solution is less sexy than a database, it would function with no technical drawbacks; and since the sharing of sourcecode already works very well, you basically erase any database-related effort from this section of the project, along with all the drawbacks of it that are causing problems. OK, that’s the background, for the curious. I won’t be able to convince management that this is an unfixable sociological problem, and that the real solution is coding around these limits of human nature, just as you would code around a bug in a 3rd party component that you can’t change. So what I have to do is exploit the unsuitableness of the database solution, and not do it using logic, but rather authority. I am aware of many reasons, and posts on this site giving reasons for one over the other; I’m not looking for lists of reasons like these (although you can add a comment if I've miss a doozy): WHY USE A DATABASE? instead of flatfile/other DB vs. file: if you need... Random Read / Transparent search optimization Advanced / varied / customizable Searching and sorting capabilities Transaction/rollback Locks, semaphores Concurrency control / Shared users Security 1-many/m-m is easier Easy modification Scalability Load Balancing Random updates / inserts / deletes Advanced query Administrative control of design, etc. SQL / learning curve Debugging / Logging Centralized / Live Backup capabilities Cached queries / dvlp & cache execution plans Interleaved update/read Referential integrity, avoid redundant/missing/corrupt/out-of-sync data Reporting (from on olap or oltp db) / turnkey generation tools [Disadvantages:] Important to get right the first time - professional design - but only b/c it's meant to last s/w & h/w cost Usu. over a network, speed issue (best vs. best design vs. local=even then a separate process req's marshalling/netwk layers/inter-p comm) indicies and query processing can stand in the way of simple processing (vs. flatfile) WHY USE FLATFILE: If you only need... Sequential Row processing only Limited usage append only (no reading, no master key/update) Only Update the record you're reading (fixed length recs only) Too big to fit into memory If Local disk / read-ahead network connection Portability / small system Email / cut & Paste / store as document by novice - simple format Low design learning curve but high cost later WHY USE IN-MEMORY/TABLE (tables, arrays, etc.): if you need... Processing a single db/ff record that was imported Known size of data Static data if hardcoding the table Narrow, unchanging use (e.g., one program or proc) -includes a class that will be shared, but encapsulates its data manipulation Extreme speed needed / high transaction frequency Random access - but search is dependent on implementation Following are some other posts about the topic: http://stackoverflow.com/questions/1499239/database-vs-flat-text-file-what-are-some-technical-reasons-for-choosing-one-over http://stackoverflow.com/questions/332825/are-flat-file-databases-any-good http://stackoverflow.com/questions/2356851/database-vs-flat-files http://stackoverflow.com/questions/514455/databases-vs-plain-text/514530 What I’d like to know is if anybody could recommend a hard, authoritative source containing these reasons. I’m looking for a paper book I can buy, or a reputable website with whitepapers about the issue (e.g., Microsoft, IBM), not counting the user-generated content on those sites. This will have a greater change to elicit a change that I’m looking for: less wasted programmer time, and more reliable programs. Thanks very much for your help. You win a prize for reading such a large post!

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• Warning: Cannot modify header information - headers already sent

  - by Pankaj Khurana

  Hi, I am using code available on http://www.forosdelweb.com/f18/zip-lib-php-archivo-zip-vacio-431133/ for creating zip file. First file-zip.lib.php <?php /* $Id: zip.lib.php,v 1.1 2004/02/14 15:21:18 anoncvs_tusedb Exp $ */ // vim: expandtab sw=4 ts=4 sts=4: /** * Zip file creation class. * Makes zip files. * * Last Modification and Extension By : * * Hasin Hayder * HomePage : www.hasinme.info * Email : [email protected] * IDE : PHP Designer 2005 * * * Originally Based on : * * http://www.zend.com/codex.php?id=535&single=1 * By Eric Mueller <[email protected]> * * http://www.zend.com/codex.php?id=470&single=1 * by Denis125 <[email protected]> * * a patch from Peter Listiak <[email protected]> for last modified * date and time of the compressed file * * Official ZIP file format: http://www.pkware.com/appnote.txt * * @access public */ class zipfile { /** * Array to store compressed data * * @var array $datasec */ var $datasec = array(); /** * Central directory * * @var array $ctrl_dir */ var $ctrl_dir = array(); /** * End of central directory record * * @var string $eof_ctrl_dir */ var $eof_ctrl_dir = "\x50\x4b\x05\x06\x00\x00\x00\x00"; /** * Last offset position * * @var integer $old_offset */ var $old_offset = 0; /** * Converts an Unix timestamp to a four byte DOS date and time format (date * in high two bytes, time in low two bytes allowing magnitude comparison). * * @param integer the current Unix timestamp * * @return integer the current date in a four byte DOS format * * @access private */ function unix2DosTime($unixtime = 0) { $timearray = ($unixtime == 0) ? getdate() : getdate($unixtime); if ($timearray['year'] < 1980) { $timearray['year'] = 1980; $timearray['mon'] = 1; $timearray['mday'] = 1; $timearray['hours'] = 0; $timearray['minutes'] = 0; $timearray['seconds'] = 0; } // end if return (($timearray['year'] - 1980) << 25) | ($timearray['mon'] << 21) | ($timearray['mday'] << 16) | ($timearray['hours'] << 11) | ($timearray['minutes'] << 5) | ($timearray['seconds'] >> 1); } // end of the 'unix2DosTime()' method /** * Adds "file" to archive * * @param string file contents * @param string name of the file in the archive (may contains the path) * @param integer the current timestamp * * @access public */ function addFile($data, $name, $time = 0) { $name = str_replace('', '/', $name); $dtime = dechex($this->unix2DosTime($time)); $hexdtime = 'x' . $dtime[6] . $dtime[7] . 'x' . $dtime[4] . $dtime[5] . 'x' . $dtime[2] . $dtime[3] . 'x' . $dtime[0] . $dtime[1]; eval('$hexdtime = "' . $hexdtime . '";'); $fr = "\x50\x4b\x03\x04"; $fr .= "\x14\x00"; // ver needed to extract $fr .= "\x00\x00"; // gen purpose bit flag $fr .= "\x08\x00"; // compression method $fr .= $hexdtime; // last mod time and date // "local file header" segment $unc_len = strlen($data); $crc = crc32($data); $zdata = gzcompress($data); $zdata = substr(substr($zdata, 0, strlen($zdata) - 4), 2); // fix crc bug $c_len = strlen($zdata); $fr .= pack('V', $crc); // crc32 $fr .= pack('V', $c_len); // compressed filesize $fr .= pack('V', $unc_len); // uncompressed filesize $fr .= pack('v', strlen($name)); // length of filename $fr .= pack('v', 0); // extra field length $fr .= $name; // "file data" segment $fr .= $zdata; // "data descriptor" segment (optional but necessary if archive is not // served as file) $fr .= pack('V', $crc); // crc32 $fr .= pack('V', $c_len); // compressed filesize $fr .= pack('V', $unc_len); // uncompressed filesize // add this entry to array $this -> datasec[] = $fr; // now add to central directory record $cdrec = "\x50\x4b\x01\x02"; $cdrec .= "\x00\x00"; // version made by $cdrec .= "\x14\x00"; // version needed to extract $cdrec .= "\x00\x00"; // gen purpose bit flag $cdrec .= "\x08\x00"; // compression method $cdrec .= $hexdtime; // last mod time & date $cdrec .= pack('V', $crc); // crc32 $cdrec .= pack('V', $c_len); // compressed filesize $cdrec .= pack('V', $unc_len); // uncompressed filesize $cdrec .= pack('v', strlen($name) ); // length of filename $cdrec .= pack('v', 0 ); // extra field length $cdrec .= pack('v', 0 ); // file comment length $cdrec .= pack('v', 0 ); // disk number start $cdrec .= pack('v', 0 ); // internal file attributes $cdrec .= pack('V', 32 ); // external file attributes - 'archive' bit set $cdrec .= pack('V', $this -> old_offset ); // relative offset of local header $this -> old_offset += strlen($fr); $cdrec .= $name; // optional extra field, file comment goes here // save to central directory $this -> ctrl_dir[] = $cdrec; } // end of the 'addFile()' method /** * Dumps out file * * @return string the zipped file * * @access public */ function file() { $data = implode('', $this -> datasec); $ctrldir = implode('', $this -> ctrl_dir); return $data . $ctrldir . $this -> eof_ctrl_dir . pack('v', sizeof($this -> ctrl_dir)) . // total # of entries "on this disk" pack('v', sizeof($this -> ctrl_dir)) . // total # of entries overall pack('V', strlen($ctrldir)) . // size of central dir pack('V', strlen($data)) . // offset to start of central dir "\x00\x00"; // .zip file comment length } // end of the 'file()' method /** * A Wrapper of original addFile Function * * Created By Hasin Hayder at 29th Jan, 1:29 AM * * @param array An Array of files with relative/absolute path to be added in Zip File * * @access public */ function addFiles($files /*Only Pass Array*/) { foreach($files as $file) { if (is_file($file)) //directory check { $data = implode("",file($file)); $this->addFile($data,$file); } } } /** * A Wrapper of original file Function * * Created By Hasin Hayder at 29th Jan, 1:29 AM * * @param string Output file name * * @access public */ function output($file) { $fp=fopen($file,"w"); fwrite($fp,$this->file()); fclose($fp); } } // end of the 'zipfile' class ?> My second file newzip.php <? include("zip.lib.php"); $ziper = new zipfile(); $ziper->addFiles(array("index.htm")); //array of files // the next three lines force an immediate download of the zip file: header("Content-type: application/octet-stream"); header("Content-disposition: attachment; filename=test.zip"); echo $ziper -> file(); ?> I am getting this warning while executing newzip.php Warning: Cannot modify header information - headers already sent by (output started at E:\xampp\htdocs\demo\zip.lib.php:233) in E:\xampp\htdocs\demo\newzip.php on line 6 I am unable to figure out the reason for the same. Please help me on this. Thanks

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• FreeBSD performance tuning. Sysctls, loader.conf, kernel

  - by SaveTheRbtz

  I wanted to share knowledge of tuning FreeBSD via sysctl.conf/loader.conf/KENCONF. It was initially based on Igor Sysoev's (author of nginx) presentation about FreeBSD tuning up to 100,000-200,000 active connections. Tunings are for FreeBSD-CURRENT. Since 7.2 amd64 some of them are tuned well by default. Prior 7.0 some of them are boot only (set via /boot/loader.conf) or does not exist at all. sysctl.conf: # No zero mapping feature # May break wine # (There are also reports about broken samba3) #security.bsd.map_at_zero=0 # If you have really busy webserver with apache13 you may run out of processes #kern.maxproc=10000 # Same for servers with apache2 / Pound #kern.threads.max_threads_per_proc=4096 # Max. backlog size kern.ipc.somaxconn=4096 # Shared memory // 7.2+ can use shared memory > 2Gb kern.ipc.shmmax=2147483648 # Sockets kern.ipc.maxsockets=204800 # Can cause this on older kernels: # http://old.nabble.com/Significant-performance-regression-for-increased-maxsockbuf-on-8.0-RELEASE-tt26745981.html#a26745981 ) kern.ipc.maxsockbuf=10485760 # Mbuf 2k clusters (on amd64 7.2+ 25600 is default) # For such high value vm.kmem_size must be increased to 3G kern.ipc.nmbclusters=262144 # Jumbo pagesize(_SC_PAGESIZE) clusters # Used as general packet storage for jumbo frames # can be monitored via `netstat -m` #kern.ipc.nmbjumbop=262144 # Jumbo 9k/16k clusters # If you are using them #kern.ipc.nmbjumbo9=65536 #kern.ipc.nmbjumbo16=32768 # For lower latency you can decrease scheduler's maximum time slice # default: stathz/10 (~ 13) #kern.sched.slice=1 # Increase max command-line length showed in `ps` (e.g for Tomcat/Java) # Default is PAGE_SIZE / 16 or 256 on x86 # This avoids commands to be presented as [executable] in `ps` # For more info see: http://www.freebsd.org/cgi/query-pr.cgi?pr=120749 kern.ps_arg_cache_limit=4096 # Every socket is a file, so increase them kern.maxfiles=204800 kern.maxfilesperproc=200000 kern.maxvnodes=200000 # On some systems HPET is almost 2 times faster than default ACPI-fast # Useful on systems with lots of clock_gettime / gettimeofday calls # See http://old.nabble.com/ACPI-fast-default-timecounter,-but-HPET-83--faster-td23248172.html # After revision 222222 HPET became default: http://svnweb.freebsd.org/base?view=revision&revision=222222 kern.timecounter.hardware=HPET # Small receive space, only usable on http-server, on file server this # should be increased to 65535 or even more #net.inet.tcp.recvspace=8192 # This is useful on Fat-Long-Pipes #net.inet.tcp.recvbuf_max=10485760 #net.inet.tcp.recvbuf_inc=65535 # Small send space is useful for http servers that serve small files # Autotuned since 7.x net.inet.tcp.sendspace=16384 # This is useful on Fat-Long-Pipes #net.inet.tcp.sendbuf_max=10485760 #net.inet.tcp.sendbuf_inc=65535 # Turn off receive autotuning # You can play with it. #net.inet.tcp.recvbuf_auto=0 #net.inet.tcp.sendbuf_auto=0 # This should be enabled if you going to use big spaces (>64k) # Also timestamp field is useful when using syncookies net.inet.tcp.rfc1323=1 # Turn this off on high-speed, lossless connections (LAN 1Gbit+) # If you set it there is no need in TCP_NODELAY sockopt (see man tcp) net.inet.tcp.delayed_ack=0 # This feature is useful if you are serving data over modems, Gigabit Ethernet, # or even high speed WAN links (or any other link with a high bandwidth delay product), # especially if you are also using window scaling or have configured a large send window. # Automatically disables on small RTT ( http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/netinet/tcp_subr.c?#rev1.237 ) # This sysctl was removed in 10-CURRENT: # See: http://www.mail-archive.com/[email protected]/msg06178.html #net.inet.tcp.inflight.enable=0 # TCP slowstart algorithm tunings # We assuming we have very fast clients #net.inet.tcp.slowstart_flightsize=100 #net.inet.tcp.local_slowstart_flightsize=100 # Disable randomizing of ports to avoid false RST # Before usage check SA here www.bsdcan.org/2006/papers/ImprovingTCPIP.pdf # (it's also says that port randomization auto-disables at some conn.rates, but I didn't checked it thou) #net.inet.ip.portrange.randomized=0 # Increase portrange # For outgoing connections only. Good for seed-boxes and ftp servers. net.inet.ip.portrange.first=1024 net.inet.ip.portrange.last=65535 # # stops route cache degregation during a high-bandwidth flood # http://www.freebsd.org/doc/en/books/handbook/securing-freebsd.html #net.inet.ip.rtexpire=2 net.inet.ip.rtminexpire=2 net.inet.ip.rtmaxcache=1024 # Security net.inet.ip.redirect=0 net.inet.ip.sourceroute=0 net.inet.ip.accept_sourceroute=0 net.inet.icmp.maskrepl=0 net.inet.icmp.log_redirect=0 net.inet.icmp.drop_redirect=1 net.inet.tcp.drop_synfin=1 # # There is also good example of sysctl.conf with comments: # http://www.thern.org/projects/sysctl.conf # # icmp may NOT rst, helpful for those pesky spoofed # icmp/udp floods that end up taking up your outgoing # bandwidth/ifqueue due to all that outgoing RST traffic. # #net.inet.tcp.icmp_may_rst=0 # Security net.inet.udp.blackhole=1 net.inet.tcp.blackhole=2 # IPv6 Security # For more info see http://www.fosslc.org/drupal/content/security-implications-ipv6 # Disable Node info replies # To see this vulnerability in action run `ping6 -a sglAac ::1` or `ping6 -w ::1` on unprotected node net.inet6.icmp6.nodeinfo=0 # Turn on IPv6 privacy extensions # For more info see proposal http://unix.derkeiler.com/Mailing-Lists/FreeBSD/net/2008-06/msg00103.html net.inet6.ip6.use_tempaddr=1 net.inet6.ip6.prefer_tempaddr=1 # Disable ICMP redirect net.inet6.icmp6.rediraccept=0 # Disable acceptation of RA and auto linklocal generation if you don't use them #net.inet6.ip6.accept_rtadv=0 #net.inet6.ip6.auto_linklocal=0 # Increases default TTL, sometimes useful # Default is 64 net.inet.ip.ttl=128 # Lessen max segment life to conserve resources # ACK waiting time in miliseconds # (default: 30000. RFC from 1979 recommends 120000) net.inet.tcp.msl=5000 # Max bumber of timewait sockets net.inet.tcp.maxtcptw=200000 # Don't use tw on local connections # As of 15 Apr 2009. Igor Sysoev says that nolocaltimewait has some buggy realization. # So disable it or now till get fixed #net.inet.tcp.nolocaltimewait=1 # FIN_WAIT_2 state fast recycle net.inet.tcp.fast_finwait2_recycle=1 # Time before tcp keepalive probe is sent # default is 2 hours (7200000) #net.inet.tcp.keepidle=60000 # Should be increased until net.inet.ip.intr_queue_drops is zero net.inet.ip.intr_queue_maxlen=4096 # Interrupt handling via multiple CPU, but with context switch. # You can play with it. Default is 1; #net.isr.direct=0 # This is for routers only #net.inet.ip.forwarding=1 #net.inet.ip.fastforwarding=1 # This speed ups dummynet when channel isn't saturated net.inet.ip.dummynet.io_fast=1 # Increase dummynet(4) hash #net.inet.ip.dummynet.hash_size=2048 #net.inet.ip.dummynet.max_chain_len # Should be increased when you have A LOT of files on server # (Increase until vfs.ufs.dirhash_mem becomes lower) vfs.ufs.dirhash_maxmem=67108864 # Note from commit http://svn.freebsd.org/base/head@211031 : # For systems with RAID volumes and/or virtualization envirnments, where # read performance is very important, increasing this sysctl tunable to 32 # or even more will demonstratively yield additional performance benefits. vfs.read_max=32 # Explicit Congestion Notification (see http://en.wikipedia.org/wiki/Explicit_Congestion_Notification) net.inet.tcp.ecn.enable=1 # Flowtable - flow caching mechanism # Useful for routers #net.inet.flowtable.enable=1 #net.inet.flowtable.nmbflows=65535 # Extreme polling tuning #kern.polling.burst_max=1000 #kern.polling.each_burst=1000 #kern.polling.reg_frac=100 #kern.polling.user_frac=1 #kern.polling.idle_poll=0 # IPFW dynamic rules and timeouts tuning # Increase dyn_buckets till net.inet.ip.fw.curr_dyn_buckets is lower net.inet.ip.fw.dyn_buckets=65536 net.inet.ip.fw.dyn_max=65536 net.inet.ip.fw.dyn_ack_lifetime=120 net.inet.ip.fw.dyn_syn_lifetime=10 net.inet.ip.fw.dyn_fin_lifetime=2 net.inet.ip.fw.dyn_short_lifetime=10 # Make packets pass firewall only once when using dummynet # i.e. packets going thru pipe are passing out from firewall with accept #net.inet.ip.fw.one_pass=1 # shm_use_phys Wires all shared pages, making them unswappable # Use this to lessen Virtual Memory Manager's work when using Shared Mem. # Useful for databases #kern.ipc.shm_use_phys=1 # ZFS # Enable prefetch. Useful for sequential load type i.e fileserver. # FreeBSD sets vfs.zfs.prefetch_disable to 1 on any i386 systems and # on any amd64 systems with less than 4GB of avaiable memory # For additional info check this nabble thread http://old.nabble.com/Samba-read-speed-performance-tuning-td27964534.html #vfs.zfs.prefetch_disable=0 # On highload servers you may notice following message in dmesg: # "Approaching the limit on PV entries, consider increasing either the # vm.pmap.shpgperproc or the vm.pmap.pv_entry_max tunable" vm.pmap.shpgperproc=2048 loader.conf: # Accept filters for data, http and DNS requests # Useful when your software uses select() instead of kevent/kqueue or when you under DDoS # DNS accf available on 8.0+ accf_data_load="YES" accf_http_load="YES" accf_dns_load="YES" # Async IO system calls aio_load="YES" # Linux specific devices in /dev # As for 8.1 it only /dev/full #lindev_load="YES" # Adds NCQ support in FreeBSD # WARNING! all ad[0-9]+ devices will be renamed to ada[0-9]+ # 8.0+ only #ahci_load="YES" #siis_load="YES" # FreeBSD 8.2+ # New Congestion Control for FreeBSD # http://caia.swin.edu.au/urp/newtcp/tools/cc_chd-readme-0.1.txt # http://www.ietf.org/proceedings/78/slides/iccrg-5.pdf # Initial merge commit message http://www.mail-archive.com/[email protected]/msg31410.html #cc_chd_load="YES" # Increase kernel memory size to 3G. # # Use ONLY if you have KVA_PAGES in kernel configuration, and you have more than 3G RAM # Otherwise panic will happen on next reboot! # # It's required for high buffer sizes: kern.ipc.nmbjumbop, kern.ipc.nmbclusters, etc # Useful on highload stateful firewalls, proxies or ZFS fileservers # (FreeBSD 7.2+ amd64 users: Check that current value is lower!) #vm.kmem_size="3G" # If your server has lots of swap (>4Gb) you should increase following value # according to http://lists.freebsd.org/pipermail/freebsd-hackers/2009-October/029616.html # Otherwise you'll be getting errors # "kernel: swap zone exhausted, increase kern.maxswzone" # kern.maxswzone="256M" # Older versions of FreeBSD can't tune maxfiles on the fly #kern.maxfiles="200000" # Useful for databases # Sets maximum data size to 1G # (FreeBSD 7.2+ amd64 users: Check that current value is lower!) #kern.maxdsiz="1G" # Maximum buffer size(vfs.maxbufspace) # You can check current one via vfs.bufspace # Should be lowered/upped depending on server's load-type # Usually decreased to preserve kmem # (default is 10% of mem) #kern.maxbcache="512M" # Sendfile buffers # For i386 only #kern.ipc.nsfbufs=10240 # FreeBSD 9+ # HPET "legacy route" support. It should allow HPET to work per-CPU # See http://www.mail-archive.com/[email protected]/msg03603.html #hint.atrtc.0.clock=0 #hint.attimer.0.clock=0 #hint.hpet.0.legacy_route=1 # syncache Hash table tuning net.inet.tcp.syncache.hashsize=1024 net.inet.tcp.syncache.bucketlimit=512 net.inet.tcp.syncache.cachelimit=65536 # Increased hostcache # Later host cache can be viewed via net.inet.tcp.hostcache.list hidden sysctl # Very useful for it's RTT RTTVAR # Must be power of two net.inet.tcp.hostcache.hashsize=65536 # hashsize * bucketlimit (which is 30 by default) # It allocates 255Mb (1966080*136) of RAM net.inet.tcp.hostcache.cachelimit=1966080 # TCP control-block Hash table tuning net.inet.tcp.tcbhashsize=4096 # Disable ipfw deny all # Should be uncommented when there is a chance that # kernel and ipfw binary may be out-of sync on next reboot #net.inet.ip.fw.default_to_accept=1 # # SIFTR (Statistical Information For TCP Research) is a kernel module that # logs a range of statistics on active TCP connections to a log file. # See prerelease notes http://groups.google.com/group/mailing.freebsd.current/browse_thread/thread/b4c18be6cdce76e4 # and man 4 sitfr #siftr_load="YES" # Enable superpages, for 7.2+ only # Also read http://lists.freebsd.org/pipermail/freebsd-hackers/2009-November/030094.html vm.pmap.pg_ps_enabled=1 # Usefull if you are using Intel-Gigabit NIC #hw.em.rxd=4096 #hw.em.txd=4096 #hw.em.rx_process_limit="-1" # Also if you have ALOT interrupts on NIC - play with following parameters # NOTE: You should set them for every NIC #dev.em.0.rx_int_delay: 250 #dev.em.0.tx_int_delay: 250 #dev.em.0.rx_abs_int_delay: 250 #dev.em.0.tx_abs_int_delay: 250 # There is also multithreaded version of em/igb drivers can be found here: # http://people.yandex-team.ru/~wawa/ # # for additional em monitoring and statistics use # sysctl dev.em.0.stats=1 ; dmesg # sysctl dev.em.0.debug=1 ; dmesg # Also after r209242 (-CURRENT) there is a separate sysctl for each stat variable; # Same tunings for igb #hw.igb.rxd=4096 #hw.igb.txd=4096 #hw.igb.rx_process_limit=100 # Some useful netisr tunables. See sysctl net.isr #net.isr.maxthreads=4 #net.isr.defaultqlimit=4096 #net.isr.maxqlimit: 10240 # Bind netisr threads to CPUs #net.isr.bindthreads=1 # # FreeBSD 9.x+ # Increase interface send queue length # See commit message http://svn.freebsd.org/viewvc/base?view=revision&revision=207554 #net.link.ifqmaxlen=1024 # Nicer boot logo =) loader_logo="beastie" And finally here is KERNCONF: # Just some of them, see also # cat /sys/{i386,amd64,}/conf/NOTES # This one useful only on i386 #options KVA_PAGES=512 # You can play with HZ in environments with high interrupt rate (default is 1000) # 100 is for my notebook to prolong it's battery life #options HZ=100 # Polling is goot on network loads with high packet rates and low-end NICs # NB! Do not enable it if you want more than one netisr thread #options DEVICE_POLLING # Eliminate datacopy on socket read-write # To take advantage with zero copy sockets you should have an MTU >= 4k # This req. is only for receiving data. # Read more in man zero_copy_sockets # Also this epic thread on kernel trap: # http://kerneltrap.org/node/6506 # Here Linus says that "anybody that does it that way (FreeBSD) is totally incompetent" #options ZERO_COPY_SOCKETS # Support TCP sign. Used for IPSec options TCP_SIGNATURE # There was stackoverflow found in KAME IPSec stack: # See http://secunia.com/advisories/43995/ # For quick workaround you can use `ipfw add deny proto ipcomp` options IPSEC # This ones can be loaded as modules. They described in loader.conf section #options ACCEPT_FILTER_DATA #options ACCEPT_FILTER_HTTP # Adding ipfw, also can be loaded as modules options IPFIREWALL # On 8.1+ you can disable verbose to see blocked packets on ipfw0 interface. # Also there is no point in compiling verbose into the kernel, because # now there is net.inet.ip.fw.verbose tunable. #options IPFIREWALL_VERBOSE #options IPFIREWALL_VERBOSE_LIMIT=10 options IPFIREWALL_FORWARD # Adding kernel NAT options IPFIREWALL_NAT options LIBALIAS # Traffic shaping options DUMMYNET # Divert, i.e. for userspace NAT options IPDIVERT # This is for OpenBSD's pf firewall device pf device pflog # pf's QoS - ALTQ options ALTQ options ALTQ_CBQ # Class Bases Queuing (CBQ) options ALTQ_RED # Random Early Detection (RED) options ALTQ_RIO # RED In/Out options ALTQ_HFSC # Hierarchical Packet Scheduler (HFSC) options ALTQ_PRIQ # Priority Queuing (PRIQ) options ALTQ_NOPCC # Required for SMP build # Pretty console # Manual can be found here http://forums.freebsd.org/showthread.php?t=6134 #options VESA #options SC_PIXEL_MODE # Disable reboot on Ctrl Alt Del #options SC_DISABLE_REBOOT # Change normal|kernel messages color options SC_NORM_ATTR=(FG_GREEN|BG_BLACK) options SC_KERNEL_CONS_ATTR=(FG_YELLOW|BG_BLACK) # More scroll space options SC_HISTORY_SIZE=8192 # Adding hardware crypto device device crypto device cryptodev # Useful network interfaces device vlan device tap #Virtual Ethernet driver device gre #IP over IP tunneling device if_bridge #Bridge interface device pfsync #synchronization interface for PF device carp #Common Address Redundancy Protocol device enc #IPsec interface device lagg #Link aggregation interface device stf #IPv4-IPv6 port # Also for my notebook, but may be used with Opteron device amdtemp # Same for Intel processors device coretemp # man 4 cpuctl device cpuctl # CPU control pseudo-device # Support for ECMP. More than one route for destination # Works even with default route so one can use it as LB for two ISP # For now code is unstable and panics (panic: rtfree 2) on route deletions. #options RADIX_MPATH # Multicast routing #options MROUTING #options PIM # Debug & DTrace options KDB # Kernel debugger related code options KDB_TRACE # Print a stack trace for a panic options KDTRACE_FRAME # amd64-only(?) options KDTRACE_HOOKS # all architectures - enable general DTrace hooks #options DDB #options DDB_CTF # all architectures - kernel ELF linker loads CTF data # Adaptive spining in lockmgr (8.x+) # See http://www.mail-archive.com/[email protected]/msg10782.html options ADAPTIVE_LOCKMGRS # UTF-8 in console (8.x+) #options TEKEN_UTF8 # FreeBSD 8.1+ # Deadlock resolver thread # For additional information see http://www.mail-archive.com/[email protected]/msg18124.html # (FYI: "resolution" is panic so use with caution) #options DEADLKRES # Increase maximum size of Raw I/O and sendfile(2) readahead #options MAXPHYS=(1024*1024) #options MAXBSIZE=(1024*1024) # For scheduler debug enable following option. # Debug will be available via `kern.sched.stats` sysctl # For more information see http://svnweb.freebsd.org/base/head/sys/conf/NOTES?view=markup #options SCHED_STATS If you are tuning network for maximum performance you may wish to play with ifconfig options like: # You can list all capabilities via `ifconfig -m` ifconfig [-]rxcsum [-]txcsum [-]tso [-]lro mtu In case you've enabled DDB in kernel config, you should edit your /etc/ddb.conf and add something like this to enable automatic reboot (and textdump as bonus): script kdb.enter.panic=textdump set; capture on; show pcpu; bt; ps; alltrace; capture off; call doadump; reset script kdb.enter.default=textdump set; capture on; bt; ps; capture off; call doadump; reset And do not forget to add ddb_enable="YES" to /etc/rc.conf Since FreeBSD 9 you can select to enable/disable flowcontrol on your NIC: # See http://en.wikipedia.org/wiki/Ethernet_flow_control and # http://www.mail-archive.com/[email protected]/msg07927.html for additional info ifconfig bge0 media auto mediaopt flowcontrol PS. Also most of FreeBSD's limits can be monitored by # vmstat -z and # limits PPS. variety of network counters can be monitored via # netstat -s In FreeBSD-9 netstat's -Q option appeared, try following command to display netisr stats # netstat -Q PPPS. also see # man 7 tuning PPPPS. I wanted to thank FreeBSD community, especially author of nginx - Igor Sysoev, nginx-ru@ and FreeBSD-performance@ mailing lists for providing useful information about FreeBSD tuning. FreeBSD WIP * Whats cooking for FreeBSD 7? * Whats cooking for FreeBSD 8? * Whats cooking for FreeBSD 9? So here is the question: What tunings are you using on yours FreeBSD servers? You can also post your /etc/sysctl.conf, /boot/loader.conf, kernel options, etc with description of its' meaning (do not copy-paste from sysctl -d). Don't forget to specify server type (web, smb, gateway, etc) Let's share experience!

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• An Introduction to ASP.NET Web API

  - by Rick Strahl

  Microsoft recently released ASP.NET MVC 4.0 and .NET 4.5 and along with it, the brand spanking new ASP.NET Web API. Web API is an exciting new addition to the ASP.NET stack that provides a new, well-designed HTTP framework for creating REST and AJAX APIs (API is Microsoft’s new jargon for a service, in case you’re wondering). Although Web API ships and installs with ASP.NET MVC 4, you can use Web API functionality in any ASP.NET project, including WebForms, WebPages and MVC or just a Web API by itself. And you can also self-host Web API in your own applications from Console, Desktop or Service applications. If you're interested in a high level overview on what ASP.NET Web API is and how it fits into the ASP.NET stack you can check out my previous post: Where does ASP.NET Web API fit? In the following article, I'll focus on a practical, by example introduction to ASP.NET Web API. All the code discussed in this article is available in GitHub: https://github.com/RickStrahl/AspNetWebApiArticle [republished from my Code Magazine Article and updated for RTM release of ASP.NET Web API] Getting Started To start I’ll create a new empty ASP.NET application to demonstrate that Web API can work with any kind of ASP.NET project. Although you can create a new project based on the ASP.NET MVC/Web API template to quickly get up and running, I’ll take you through the manual setup process, because one common use case is to add Web API functionality to an existing ASP.NET application. This process describes the steps needed to hook up Web API to any ASP.NET 4.0 application. Start by creating an ASP.NET Empty Project. Then create a new folder in the project called Controllers. Add a Web API Controller Class Once you have any kind of ASP.NET project open, you can add a Web API Controller class to it. Web API Controllers are very similar to MVC Controller classes, but they work in any kind of project. Add a new item to this folder by using the Add New Item option in Visual Studio and choose Web API Controller Class, as shown in Figure 1. Figure 1: This is how you create a new Controller Class in Visual Studio   Make sure that the name of the controller class includes Controller at the end of it, which is required in order for Web API routing to find it. Here, the name for the class is AlbumApiController. For this example, I’ll use a Music Album model to demonstrate basic behavior of Web API. The model consists of albums and related songs where an album has properties like Name, Artist and YearReleased and a list of songs with a SongName and SongLength as well as an AlbumId that links it to the album. You can find the code for the model (and the rest of these samples) on Github. To add the file manually, create a new folder called Model, and add a new class Album.cs and copy the code into it. There’s a static AlbumData class with a static CreateSampleAlbumData() method that creates a short list of albums on a static .Current that I’ll use for the examples. Before we look at what goes into the controller class though, let’s hook up routing so we can access this new controller. Hooking up Routing in Global.asax To start, I need to perform the one required configuration task in order for Web API to work: I need to configure routing to the controller. Like MVC, Web API uses routing to provide clean, extension-less URLs to controller methods. Using an extension method to ASP.NET’s static RouteTable class, you can use the MapHttpRoute() (in the System.Web.Http namespace) method to hook-up the routing during Application_Start in global.asax.cs shown in Listing 1.using System; using System.Web.Routing; using System.Web.Http; namespace AspNetWebApi { public class Global : System.Web.HttpApplication { protected void Application_Start(object sender, EventArgs e) { RouteTable.Routes.MapHttpRoute( name: "AlbumVerbs", routeTemplate: "albums/{title}", defaults: new { symbol = RouteParameter.Optional, controller="AlbumApi" } ); } } } This route configures Web API to direct URLs that start with an albums folder to the AlbumApiController class. Routing in ASP.NET is used to create extensionless URLs and allows you to map segments of the URL to specific Route Value parameters. A route parameter, with a name inside curly brackets like {name}, is mapped to parameters on the controller methods. Route parameters can be optional, and there are two special route parameters – controller and action – that determine the controller to call and the method to activate respectively. HTTP Verb Routing Routing in Web API can route requests by HTTP Verb in addition to standard {controller},{action} routing. For the first examples, I use HTTP Verb routing, as shown Listing 1. Notice that the route I’ve defined does not include an {action} route value or action value in the defaults. Rather, Web API can use the HTTP Verb in this route to determine the method to call the controller, and a GET request maps to any method that starts with Get. So methods called Get() or GetAlbums() are matched by a GET request and a POST request maps to a Post() or PostAlbum(). Web API matches a method by name and parameter signature to match a route, query string or POST values. In lieu of the method name, the [HttpGet,HttpPost,HttpPut,HttpDelete, etc] attributes can also be used to designate the accepted verbs explicitly if you don’t want to follow the verb naming conventions. Although HTTP Verb routing is a good practice for REST style resource APIs, it’s not required and you can still use more traditional routes with an explicit {action} route parameter. When {action} is supplied, the HTTP verb routing is ignored. I’ll talk more about alternate routes later. When you’re finished with initial creation of files, your project should look like Figure 2.   Figure 2: The initial project has the new API Controller Album model   Creating a small Album Model Now it’s time to create some controller methods to serve data. For these examples, I’ll use a very simple Album and Songs model to play with, as shown in Listing 2. public class Song { public string AlbumId { get; set; } [Required, StringLength(80)] public string SongName { get; set; } [StringLength(5)] public string SongLength { get; set; } } public class Album { public string Id { get; set; } [Required, StringLength(80)] public string AlbumName { get; set; } [StringLength(80)] public string Artist { get; set; } public int YearReleased { get; set; } public DateTime Entered { get; set; } [StringLength(150)] public string AlbumImageUrl { get; set; } [StringLength(200)] public string AmazonUrl { get; set; } public virtual List<Song> Songs { get; set; } public Album() { Songs = new List<Song>(); Entered = DateTime.Now; // Poor man's unique Id off GUID hash Id = Guid.NewGuid().GetHashCode().ToString("x"); } public void AddSong(string songName, string songLength = null) { this.Songs.Add(new Song() { AlbumId = this.Id, SongName = songName, SongLength = songLength }); } } Once the model has been created, I also added an AlbumData class that generates some static data in memory that is loaded onto a static .Current member. The signature of this class looks like this and that's what I'll access to retrieve the base data:public static class AlbumData { // sample data - static list public static List<Album> Current = CreateSampleAlbumData(); /// <summary> /// Create some sample data /// </summary> /// <returns></returns> public static List<Album> CreateSampleAlbumData() { … }} You can check out the full code for the data generation online. Creating an AlbumApiController Web API shares many concepts of ASP.NET MVC, and the implementation of your API logic is done by implementing a subclass of the System.Web.Http.ApiController class. Each public method in the implemented controller is a potential endpoint for the HTTP API, as long as a matching route can be found to invoke it. The class name you create should end in Controller, which is how Web API matches the controller route value to figure out which class to invoke. Inside the controller you can implement methods that take standard .NET input parameters and return .NET values as results. Web API’s binding tries to match POST data, route values, form values or query string values to your parameters. Because the controller is configured for HTTP Verb based routing (no {action} parameter in the route), any methods that start with Getxxxx() are called by an HTTP GET operation. You can have multiple methods that match each HTTP Verb as long as the parameter signatures are different and can be matched by Web API. In Listing 3, I create an AlbumApiController with two methods to retrieve a list of albums and a single album by its title .public class AlbumApiController : ApiController { public IEnumerable<Album> GetAlbums() { var albums = AlbumData.Current.OrderBy(alb => alb.Artist); return albums; } public Album GetAlbum(string title) { var album = AlbumData.Current .SingleOrDefault(alb => alb.AlbumName.Contains(title)); return album; }} To access the first two requests, you can use the following URLs in your browser: http://localhost/aspnetWebApi/albumshttp://localhost/aspnetWebApi/albums/Dirty%20Deeds Note that you’re not specifying the actions of GetAlbum or GetAlbums in these URLs. Instead Web API’s routing uses HTTP GET verb to route to these methods that start with Getxxx() with the first mapping to the parameterless GetAlbums() method and the latter to the GetAlbum(title) method that receives the title parameter mapped as optional in the route. Content Negotiation When you access any of the URLs above from a browser, you get either an XML or JSON result returned back. The album list result for Chrome 17 and Internet Explorer 9 is shown Figure 3. Figure 3: Web API responses can vary depending on the browser used, demonstrating Content Negotiation in action as these two browsers send different HTTP Accept headers.   Notice that the results are not the same: Chrome returns an XML response and IE9 returns a JSON response. Whoa, what’s going on here? Shouldn’t we see the same result in both browsers? Actually, no. Web API determines what type of content to return based on Accept headers. HTTP clients, like browsers, use Accept headers to specify what kind of content they’d like to see returned. Browsers generally ask for HTML first, followed by a few additional content types. Chrome (and most other major browsers) ask for: Accept: text/html, application/xhtml+xml,application/xml; q=0.9,*/*;q=0.8 IE9 asks for: Accept: text/html, application/xhtml+xml, */* Note that Chrome’s Accept header includes application/xml, which Web API finds in its list of supported media types and returns an XML response. IE9 does not include an Accept header type that works on Web API by default, and so it returns the default format, which is JSON. This is an important and very useful feature that was missing from any previous Microsoft REST tools: Web API automatically switches output formats based on HTTP Accept headers. Nowhere in the server code above do you have to explicitly specify the output format. Rather, Web API determines what format the client is requesting based on the Accept headers and automatically returns the result based on the available formatters. This means that a single method can handle both XML and JSON results.. Using this simple approach makes it very easy to create a single controller method that can return JSON, XML, ATOM or even OData feeds by providing the appropriate Accept header from the client. By default you don’t have to worry about the output format in your code. Note that you can still specify an explicit output format if you choose, either globally by overriding the installed formatters, or individually by returning a lower level HttpResponseMessage instance and setting the formatter explicitly. More on that in a minute. Along the same lines, any content sent to the server via POST/PUT is parsed by Web API based on the HTTP Content-type of the data sent. The same formats allowed for output are also allowed on input. Again, you don’t have to do anything in your code – Web API automatically performs the deserialization from the content. Accessing Web API JSON Data with jQuery A very common scenario for Web API endpoints is to retrieve data for AJAX calls from the Web browser. Because JSON is the default format for Web API, it’s easy to access data from the server using jQuery and its getJSON() method. This example receives the albums array from GetAlbums() and databinds it into the page using knockout.js.$.getJSON("albums/", function (albums) { // make knockout template visible $(".album").show(); // create view object and attach array var view = { albums: albums }; ko.applyBindings(view); }); Figure 4 shows this and the next example’s HTML output. You can check out the complete HTML and script code at http://goo.gl/Ix33C (.html) and http://goo.gl/tETlg (.js). Figu Figure 4: The Album Display sample uses JSON data loaded from Web API.   The result from the getJSON() call is a JavaScript object of the server result, which comes back as a JavaScript array. In the code, I use knockout.js to bind this array into the UI, which as you can see, requires very little code, instead using knockout’s data-bind attributes to bind server data to the UI. Of course, this is just one way to use the data – it’s entirely up to you to decide what to do with the data in your client code. Along the same lines, I can retrieve a single album to display when the user clicks on an album. The response returns the album information and a child array with all the songs. The code to do this is very similar to the last example where we pulled the albums array:$(".albumlink").live("click", function () { var id = $(this).data("id"); // title $.getJSON("albums/" + id, function (album) { ko.applyBindings(album, $("#divAlbumDialog")[0]); $("#divAlbumDialog").show(); }); }); Here the URL looks like this: /albums/Dirty%20Deeds, where the title is the ID captured from the clicked element’s data ID attribute. Explicitly Overriding Output Format When Web API automatically converts output using content negotiation, it does so by matching Accept header media types to the GlobalConfiguration.Configuration.Formatters and the SupportedMediaTypes of each individual formatter. You can add and remove formatters to globally affect what formats are available and it’s easy to create and plug in custom formatters.The example project includes a JSONP formatter that can be plugged in to provide JSONP support for requests that have a callback= querystring parameter. Adding, removing or replacing formatters is a global option you can use to manipulate content. It’s beyond the scope of this introduction to show how it works, but you can review the sample code or check out my blog entry on the subject (http://goo.gl/UAzaR). If automatic processing is not desirable in a particular Controller method, you can override the response output explicitly by returning an HttpResponseMessage instance. HttpResponseMessage is similar to ActionResult in ASP.NET MVC in that it’s a common way to return an abstract result message that contains content. HttpResponseMessage s parsed by the Web API framework using standard interfaces to retrieve the response data, status code, headers and so on[MS2] . Web API turns every response – including those Controller methods that return static results – into HttpResponseMessage instances. Explicitly returning an HttpResponseMessage instance gives you full control over the output and lets you mostly bypass WebAPI’s post-processing of the HTTP response on your behalf. HttpResponseMessage allows you to customize the response in great detail. Web API’s attention to detail in the HTTP spec really shows; many HTTP options are exposed as properties and enumerations with detailed IntelliSense comments. Even if you’re new to building REST-based interfaces, the API guides you in the right direction for returning valid responses and response codes. For example, assume that I always want to return JSON from the GetAlbums() controller method and ignore the default media type content negotiation. To do this, I can adjust the output format and headers as shown in Listing 4.public HttpResponseMessage GetAlbums() { var albums = AlbumData.Current.OrderBy(alb => alb.Artist); // Create a new HttpResponse with Json Formatter explicitly var resp = new HttpResponseMessage(HttpStatusCode.OK); resp.Content = new ObjectContent<IEnumerable<Album>>( albums, new JsonMediaTypeFormatter()); // Get Default Formatter based on Content Negotiation //var resp = Request.CreateResponse<IEnumerable<Album>>(HttpStatusCode.OK, albums); resp.Headers.ConnectionClose = true; resp.Headers.CacheControl = new CacheControlHeaderValue(); resp.Headers.CacheControl.Public = true; return resp; } This example returns the same IEnumerable<Album> value, but it wraps the response into an HttpResponseMessage so you can control the entire HTTP message result including the headers, formatter and status code. In Listing 4, I explicitly specify the formatter using the JsonMediaTypeFormatter to always force the content to JSON.  If you prefer to use the default content negotiation with HttpResponseMessage results, you can create the Response instance using the Request.CreateResponse method:var resp = Request.CreateResponse<IEnumerable<Album>>(HttpStatusCode.OK, albums); This provides you an HttpResponse object that's pre-configured with the default formatter based on Content Negotiation. Once you have an HttpResponse object you can easily control most HTTP aspects on this object. What's sweet here is that there are many more detailed properties on HttpResponse than the core ASP.NET Response object, with most options being explicitly configurable with enumerations that make it easy to pick the right headers and response codes from a list of valid codes. It makes HTTP features available much more discoverable even for non-hardcore REST/HTTP geeks. Non-Serialized Results The output returned doesn’t have to be a serialized value but can also be raw data, like strings, binary data or streams. You can use the HttpResponseMessage.Content object to set a number of common Content classes. Listing 5 shows how to return a binary image using the ByteArrayContent class from a Controller method. [HttpGet] public HttpResponseMessage AlbumArt(string title) { var album = AlbumData.Current.FirstOrDefault(abl => abl.AlbumName.StartsWith(title)); if (album == null) { var resp = Request.CreateResponse<ApiMessageError>( HttpStatusCode.NotFound, new ApiMessageError("Album not found")); return resp; } // kinda silly - we would normally serve this directly // but hey - it's a demo. var http = new WebClient(); var imageData = http.DownloadData(album.AlbumImageUrl); // create response and return var result = new HttpResponseMessage(HttpStatusCode.OK); result.Content = new ByteArrayContent(imageData); result.Content.Headers.ContentType = new MediaTypeHeaderValue("image/jpeg"); return result; } The image retrieval from Amazon is contrived, but it shows how to return binary data using ByteArrayContent. It also demonstrates that you can easily return multiple types of content from a single controller method, which is actually quite common. If an error occurs - such as a resource can’t be found or a validation error – you can return an error response to the client that’s very specific to the error. In GetAlbumArt(), if the album can’t be found, we want to return a 404 Not Found status (and realistically no error, as it’s an image). Note that if you are not using HTTP Verb-based routing or not accessing a method that starts with Get/Post etc., you have to specify one or more HTTP Verb attributes on the method explicitly. Here, I used the [HttpGet] attribute to serve the image. Another option to handle the error could be to return a fixed placeholder image if no album could be matched or the album doesn’t have an image. When returning an error code, you can also return a strongly typed response to the client. For example, you can set the 404 status code and also return a custom error object (ApiMessageError is a class I defined) like this:return Request.CreateResponse<ApiMessageError>( HttpStatusCode.NotFound, new ApiMessageError("Album not found") );   If the album can be found, the image will be returned. The image is downloaded into a byte[] array, and then assigned to the result’s Content property. I created a new ByteArrayContent instance and assigned the image’s bytes and the content type so that it displays properly in the browser. There are other content classes available: StringContent, StreamContent, ByteArrayContent, MultipartContent, and ObjectContent are at your disposal to return just about any kind of content. You can create your own Content classes if you frequently return custom types and handle the default formatter assignments that should be used to send the data out . Although HttpResponseMessage results require more code than returning a plain .NET value from a method, it allows much more control over the actual HTTP processing than automatic processing. It also makes it much easier to test your controller methods as you get a response object that you can check for specific status codes and output messages rather than just a result value. Routing Again Ok, let’s get back to the image example. Using the original routing we have setup using HTTP Verb routing there's no good way to serve the image. In order to return my album art image I’d like to use a URL like this: http://localhost/aspnetWebApi/albums/Dirty%20Deeds/image In order to create a URL like this, I have to create a new Controller because my earlier routes pointed to the AlbumApiController using HTTP Verb routing. HTTP Verb based routing is great for representing a single set of resources such as albums. You can map operations like add, delete, update and read easily using HTTP Verbs. But you cannot mix action based routing into a an HTTP Verb routing controller - you can only map HTTP Verbs and each method has to be unique based on parameter signature. You can't have multiple GET operations to methods with the same signature. So GetImage(string id) and GetAlbum(string title) are in conflict in an HTTP GET routing scenario. In fact, I was unable to make the above Image URL work with any combination of HTTP Verb plus Custom routing using the single Albums controller. There are number of ways around this, but all involve additional controllers.  Personally, I think it’s easier to use explicit Action routing and then add custom routes if you need to simplify your URLs further. So in order to accommodate some of the other examples, I created another controller – AlbumRpcApiController – to handle all requests that are explicitly routed via actions (/albums/rpc/AlbumArt) or are custom routed with explicit routes defined in the HttpConfiguration. I added the AlbumArt() method to this new AlbumRpcApiController class. For the image URL to work with the new AlbumRpcApiController, you need a custom route placed before the default route from Listing 1.RouteTable.Routes.MapHttpRoute( name: "AlbumRpcApiAction", routeTemplate: "albums/rpc/{action}/{title}", defaults: new { title = RouteParameter.Optional, controller = "AlbumRpcApi", action = "GetAblums" } ); Now I can use either of the following URLs to access the image: Custom route: (/albums/rpc/{title}/image)http://localhost/aspnetWebApi/albums/PowerAge/image Action route: (/albums/rpc/action/{title})http://localhost/aspnetWebAPI/albums/rpc/albumart/PowerAge Sending Data to the Server To send data to the server and add a new album, you can use an HTTP POST operation. Since I’m using HTTP Verb-based routing in the original AlbumApiController, I can implement a method called PostAlbum()to accept a new album from the client. Listing 6 shows the Web API code to add a new album.public HttpResponseMessage PostAlbum(Album album) { if (!this.ModelState.IsValid) { // my custom error class var error = new ApiMessageError() { message = "Model is invalid" }; // add errors into our client error model for client foreach (var prop in ModelState.Values) { var modelError = prop.Errors.FirstOrDefault(); if (!string.IsNullOrEmpty(modelError.ErrorMessage)) error.errors.Add(modelError.ErrorMessage); else error.errors.Add(modelError.Exception.Message); } return Request.CreateResponse<ApiMessageError>(HttpStatusCode.Conflict, error); } // update song id which isn't provided foreach (var song in album.Songs) song.AlbumId = album.Id; // see if album exists already var matchedAlbum = AlbumData.Current .SingleOrDefault(alb => alb.Id == album.Id || alb.AlbumName == album.AlbumName); if (matchedAlbum == null) AlbumData.Current.Add(album); else matchedAlbum = album; // return a string to show that the value got here var resp = Request.CreateResponse(HttpStatusCode.OK, string.Empty); resp.Content = new StringContent(album.AlbumName + " " + album.Entered.ToString(), Encoding.UTF8, "text/plain"); return resp; } The PostAlbum() method receives an album parameter, which is automatically deserialized from the POST buffer the client sent. The data passed from the client can be either XML or JSON. Web API automatically figures out what format it needs to deserialize based on the content type and binds the content to the album object. Web API uses model binding to bind the request content to the parameter(s) of controller methods. Like MVC you can check the model by looking at ModelState.IsValid. If it’s not valid, you can run through the ModelState.Values collection and check each binding for errors. Here I collect the error messages into a string array that gets passed back to the client via the result ApiErrorMessage object. When a binding error occurs, you’ll want to return an HTTP error response and it’s best to do that with an HttpResponseMessage result. In Listing 6, I used a custom error class that holds a message and an array of detailed error messages for each binding error. I used this object as the content to return to the client along with my Conflict HTTP Status Code response. If binding succeeds, the example returns a string with the name and date entered to demonstrate that you captured the data. Normally, a method like this should return a Boolean or no response at all (HttpStatusCode.NoConent). The sample uses a simple static list to hold albums, so once you’ve added the album using the Post operation, you can hit the /albums/ URL to see that the new album was added. The client jQuery code to call the POST operation from the client with jQuery is shown in Listing 7. var id = new Date().getTime().toString(); var album = { "Id": id, "AlbumName": "Power Age", "Artist": "AC/DC", "YearReleased": 1977, "Entered": "2002-03-11T18:24:43.5580794-10:00", "AlbumImageUrl": http://ecx.images-amazon.com/images/…, "AmazonUrl": http://www.amazon.com/…, "Songs": [ { "SongName": "Rock 'n Roll Damnation", "SongLength": 3.12}, { "SongName": "Downpayment Blues", "SongLength": 4.22 }, { "SongName": "Riff Raff", "SongLength": 2.42 } ] } $.ajax( { url: "albums/", type: "POST", contentType: "application/json", data: JSON.stringify(album), processData: false, beforeSend: function (xhr) { // not required since JSON is default output xhr.setRequestHeader("Accept", "application/json"); }, success: function (result) { // reload list of albums page.loadAlbums(); }, error: function (xhr, status, p3, p4) { var err = "Error"; if (xhr.responseText && xhr.responseText[0] == "{") err = JSON.parse(xhr.responseText).message; alert(err); } }); The code in Listing 7 creates an album object in JavaScript to match the structure of the .NET Album class. This object is passed to the $.ajax() function to send to the server as POST. The data is turned into JSON and the content type set to application/json so that the server knows what to convert when deserializing in the Album instance. The jQuery code hooks up success and failure events. Success returns the result data, which is a string that’s echoed back with an alert box. If an error occurs, jQuery returns the XHR instance and status code. You can check the XHR to see if a JSON object is embedded and if it is, you can extract it by de-serializing it and accessing the .message property. REST standards suggest that updates to existing resources should use PUT operations. REST standards aside, I’m not a big fan of separating out inserts and updates so I tend to have a single method that handles both. But if you want to follow REST suggestions, you can create a PUT method that handles updates by forwarding the PUT operation to the POST method:public HttpResponseMessage PutAlbum(Album album) { return PostAlbum(album); } To make the corresponding $.ajax() call, all you have to change from Listing 7 is the type: from POST to PUT. Model Binding with UrlEncoded POST Variables In the example in Listing 7 I used JSON objects to post a serialized object to a server method that accepted an strongly typed object with the same structure, which is a common way to send data to the server. However, Web API supports a number of different ways that data can be received by server methods. For example, another common way is to use plain UrlEncoded POST  values to send to the server. Web API supports Model Binding that works similar (but not the same) as MVC's model binding where POST variables are mapped to properties of object parameters of the target method. This is actually quite common for AJAX calls that want to avoid serialization and the potential requirement of a JSON parser on older browsers. For example, using jQUery you might use the $.post() method to send a new album to the server (albeit one without songs) using code like the following:$.post("albums/",{AlbumName: "Dirty Deeds", YearReleased: 1976 … },albumPostCallback); Although the code looks very similar to the client code we used before passing JSON, here the data passed is URL encoded values (AlbumName=Dirty+Deeds&YearReleased=1976 etc.). Web API then takes this POST data and maps each of the POST values to the properties of the Album object in the method's parameter. Although the client code is different the server can both handle the JSON object, or the UrlEncoded POST values. Dynamic Access to POST Data There are also a few options available to dynamically access POST data, if you know what type of data you're dealing with. If you have POST UrlEncoded values, you can dynamically using a FormsDataCollection:[HttpPost] public string PostAlbum(FormDataCollection form) { return string.Format("{0} - released {1}", form.Get("AlbumName"),form.Get("RearReleased")); } The FormDataCollection is a very simple object, that essentially provides the same functionality as Request.Form[] in ASP.NET. Request.Form[] still works if you're running hosted in an ASP.NET application. However as a general rule, while ASP.NET's functionality is always available when running Web API hosted inside of an  ASP.NET application, using the built in classes specific to Web API makes it possible to run Web API applications in a self hosted environment outside of ASP.NET. If your client is sending JSON to your server, and you don't want to map the JSON to a strongly typed object because you only want to retrieve a few simple values, you can also accept a JObject parameter in your API methods:[HttpPost] public string PostAlbum(JObject jsonData) { dynamic json = jsonData; JObject jalbum = json.Album; JObject juser = json.User; string token = json.UserToken; var album = jalbum.ToObject<Album>(); var user = juser.ToObject<User>(); return String.Format("{0} {1} {2}", album.AlbumName, user.Name, token); } There quite a few options available to you to receive data with Web API, which gives you more choices for the right tool for the job. Unfortunately one shortcoming of Web API is that POST data is always mapped to a single parameter. This means you can't pass multiple POST parameters to methods that receive POST data. It's possible to accept multiple parameters, but only one can map to the POST content - the others have to come from the query string or route values. I have a couple of Blog POSTs that explain what works and what doesn't here: Passing multiple POST parameters to Web API Controller Methods Mapping UrlEncoded POST Values in ASP.NET Web API   Handling Delete Operations Finally, to round out the server API code of the album example we've been discussin, here’s the DELETE verb controller method that allows removal of an album by its title:public HttpResponseMessage DeleteAlbum(string title) { var matchedAlbum = AlbumData.Current.Where(alb => alb.AlbumName == title) .SingleOrDefault(); if (matchedAlbum == null) return new HttpResponseMessage(HttpStatusCode.NotFound); AlbumData.Current.Remove(matchedAlbum); return new HttpResponseMessage(HttpStatusCode.NoContent); } To call this action method using jQuery, you can use:$(".removeimage").live("click", function () { var $el = $(this).parent(".album"); var txt = $el.find("a").text(); $.ajax({ url: "albums/" + encodeURIComponent(txt), type: "Delete", success: function (result) { $el.fadeOut().remove(); }, error: jqError }); }   Note the use of the DELETE verb in the $.ajax() call, which routes to DeleteAlbum on the server. DELETE is a non-content operation, so you supply a resource ID (the title) via route value or the querystring. Routing Conflicts In all requests with the exception of the AlbumArt image example shown so far, I used HTTP Verb routing that I set up in Listing 1. HTTP Verb Routing is a recommendation that is in line with typical REST access to HTTP resources. However, it takes quite a bit of effort to create REST-compliant API implementations based only on HTTP Verb routing only. You saw one example that didn’t really fit – the return of an image where I created a custom route albums/{title}/image that required creation of a second controller and a custom route to work. HTTP Verb routing to a controller does not mix with custom or action routing to the same controller because of the limited mapping of HTTP verbs imposed by HTTP Verb routing. To understand some of the problems with verb routing, let’s look at another example. Let’s say you create a GetSortableAlbums() method like this and add it to the original AlbumApiController accessed via HTTP Verb routing:[HttpGet] public IQueryable<Album> SortableAlbums() { var albums = AlbumData.Current; // generally should be done only on actual queryable results (EF etc.) // Done here because we're running with a static list but otherwise might be slow return albums.AsQueryable(); } If you compile this code and try to now access the /albums/ link, you get an error: Multiple Actions were found that match the request. HTTP Verb routing only allows access to one GET operation per parameter/route value match. If more than one method exists with the same parameter signature, it doesn’t work. As I mentioned earlier for the image display, the only solution to get this method to work is to throw it into another controller. Because I already set up the AlbumRpcApiController I can add the method there. First, I should rename the method to SortableAlbums() so I’m not using a Get prefix for the method. This also makes the action parameter look cleaner in the URL - it looks less like a method and more like a noun. I can then create a new route that handles direct-action mapping:RouteTable.Routes.MapHttpRoute( name: "AlbumRpcApiAction", routeTemplate: "albums/rpc/{action}/{title}", defaults: new { title = RouteParameter.Optional, controller = "AlbumRpcApi", action = "GetAblums" } ); As I am explicitly adding a route segment – rpc – into the route template, I can now reference explicit methods in the Web API controller using URLs like this: http://localhost/AspNetWebApi/rpc/SortableAlbums Error Handling I’ve already done some minimal error handling in the examples. For example in Listing 6, I detected some known-error scenarios like model validation failing or a resource not being found and returning an appropriate HttpResponseMessage result. But what happens if your code just blows up or causes an exception? If you have a controller method, like this:[HttpGet] public void ThrowException() { throw new UnauthorizedAccessException("Unauthorized Access Sucka"); } You can call it with this: http://localhost/AspNetWebApi/albums/rpc/ThrowException The default exception handling displays a 500-status response with the serialized exception on the local computer only. When you connect from a remote computer, Web API throws back a 500  HTTP Error with no data returned (IIS then adds its HTML error page). The behavior is configurable in the GlobalConfiguration:GlobalConfiguration .Configuration .IncludeErrorDetailPolicy = IncludeErrorDetailPolicy.Never; If you want more control over your error responses sent from code, you can throw explicit error responses yourself using HttpResponseException. When you throw an HttpResponseException the response parameter is used to generate the output for the Controller action. [HttpGet] public void ThrowError() { var resp = Request.CreateResponse<ApiMessageError>( HttpStatusCode.BadRequest, new ApiMessageError("Your code stinks!")); throw new HttpResponseException(resp); } Throwing an HttpResponseException stops the processing of the controller method and immediately returns the response you passed to the exception. Unlike other Exceptions fired inside of WebAPI, HttpResponseException bypasses the Exception Filters installed and instead just outputs the response you provide. In this case, the serialized ApiMessageError result string is returned in the default serialization format – XML or JSON. You can pass any content to HttpResponseMessage, which includes creating your own exception objects and consistently returning error messages to the client. Here’s a small helper method on the controller that you might use to send exception info back to the client consistently:private void ThrowSafeException(string message, HttpStatusCode statusCode = HttpStatusCode.BadRequest) { var errResponse = Request.CreateResponse<ApiMessageError>(statusCode, new ApiMessageError() { message = message }); throw new HttpResponseException(errResponse); } You can then use it to output any captured errors from code:[HttpGet] public void ThrowErrorSafe() { try { List<string> list = null; list.Add("Rick"); } catch (Exception ex) { ThrowSafeException(ex.Message); } }   Exception Filters Another more global solution is to create an Exception Filter. Filters in Web API provide the ability to pre- and post-process controller method operations. An exception filter looks at all exceptions fired and then optionally creates an HttpResponseMessage result. Listing 8 shows an example of a basic Exception filter implementation.public class UnhandledExceptionFilter : ExceptionFilterAttribute { public override void OnException(HttpActionExecutedContext context) { HttpStatusCode status = HttpStatusCode.InternalServerError; var exType = context.Exception.GetType(); if (exType == typeof(UnauthorizedAccessException)) status = HttpStatusCode.Unauthorized; else if (exType == typeof(ArgumentException)) status = HttpStatusCode.NotFound; var apiError = new ApiMessageError() { message = context.Exception.Message }; // create a new response and attach our ApiError object // which now gets returned on ANY exception result var errorResponse = context.Request.CreateResponse<ApiMessageError>(status, apiError); context.Response = errorResponse; base.OnException(context); } } Exception Filter Attributes can be assigned to an ApiController class like this:[UnhandledExceptionFilter] public class AlbumRpcApiController : ApiController or you can globally assign it to all controllers by adding it to the HTTP Configuration's Filters collection:GlobalConfiguration.Configuration.Filters.Add(new UnhandledExceptionFilter()); The latter is a great way to get global error trapping so that all errors (short of hard IIS errors and explicit HttpResponseException errors) return a valid error response that includes error information in the form of a known-error object. Using a filter like this allows you to throw an exception as you normally would and have your filter create a response in the appropriate output format that the client expects. For example, an AJAX application can on failure expect to see a JSON error result that corresponds to the real error that occurred rather than a 500 error along with HTML error page that IIS throws up. You can even create some custom exceptions so you can differentiate your own exceptions from unhandled system exceptions - you often don't want to display error information from 'unknown' exceptions as they may contain sensitive system information or info that's not generally useful to users of your application/site. This is just one example of how ASP.NET Web API is configurable and extensible. Exception filters are just one example of how you can plug-in into the Web API request flow to modify output. Many more hooks exist and I’ll take a closer look at extensibility in Part 2 of this article in the future. Summary Web API is a big improvement over previous Microsoft REST and AJAX toolkits. The key features to its usefulness are its ease of use with simple controller based logic, familiar MVC-style routing, low configuration impact, extensibility at all levels and tight attention to exposing and making HTTP semantics easily discoverable and easy to use. Although none of the concepts used in Web API are new or radical, Web API combines the best of previous platforms into a single framework that’s highly functional, easy to work with, and extensible to boot. I think that Microsoft has hit a home run with Web API. Related Resources Where does ASP.NET Web API fit? Sample Source Code on GitHub Passing multiple POST parameters to Web API Controller Methods Mapping UrlEncoded POST Values in ASP.NET Web API Creating a JSONP Formatter for ASP.NET Web API Removing the XML Formatter from ASP.NET Web API Applications© Rick Strahl, West Wind Technologies, 2005-2012Posted in Web Api   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• SQLAuthority News – TechEd India – April 12-14, 2010 Bangalore – An Unforgettable Experience – An Op

  - by pinaldave

  TechEd India was one of the largest Technology events in India led by Microsoft. This event was attended by more than 3,000 technology enthusiasts, making it one of the most well-organized events of the year. Though I attempted to attend almost all the technology events here, I have not seen any bigger or better event in Indian subcontinents other than this. There are 21 Technical Tracks at Tech·Ed India 2010 that span more than 745 learning opportunities. I was fortunate enough to be a part of this whole event as a speaker and a delegate, as well. TechEd India Speaker Badge and A Token of Lifetime Hotel Selection I presented three different sessions at TechEd India and was also a part of panel discussion. (The details of the sessions are given at the end of this blog post.) Due to extensive traveling, I stay away from my family occasionally. For this reason, I took my wife – Nupur and daughter Shaivi (8 months old) to the event along with me. We stayed at the same hotel where the event was organized so as to maximize my time bonding with my family and to have more time in networking with technology community, at the same time. The hotel Lalit Ashok is the largest and most luxurious venue one can find in Bangalore, located in the middle of the city. The cost of the hotel was a bit pricey, but looking at all the advantages, I had decided to ask for a booking there. Hotel Lalit Ashok Nupur Dave and Shaivi Dave Arrival Day – DAY 0 – April 11, 2010 I reached the event a day earlier, and that was one wise decision for I was able to relax a bit and go over my presentation for the next day’s course. I am a kind of person who likes to get everything ready ahead of time. I was also able to enjoy a pleasant evening with several Microsoft employees and my family friends. I even checked out the location where I would be doing presentations the next day. I was fortunate enough to meet Bijoy Singhal from Microsoft who helped me out with a few of the logistics issues that occured the day before. I was not aware of the fact that the very next day he was going to be “The Man” of the TechEd 2010 event. Vinod Kumar from Microsoft was really very kind as he talked to me regarding my subsequent session. He gave me some suggestions which were really helpful that I was able to incorporate them during my presentation. Finally, I was able to meet Abhishek Kant from Microsoft; his valuable suggestions and unlimited passion have inspired many people like me to work with the Community. Pradipta from Microsoft was also around, being extremely busy with logistics; however, in those busy times, he did find some good spare time to have a chat with me and the other Community leaders. I also met Harish Ranganathan and Sachin Rathi, both from Microsoft. It was so interesting to listen to both of them talking about SharePoint. I just have no words to express my overwhelmed spirit because of all these passionate young guys - Pradipta,Vinod, Bijoy, Harish, Sachin and Ahishek (of course!). Map of TechEd India 2010 Event Day 1 – April 12, 2010 From morning until night time, today was truly a very busy day for me. I had two presentations and one panel discussion for the day. Needless to say, I had a few meetings to attend as well. The day started with a keynote from S. Somaseger where he announced the launch of Visual Studio 2010. The keynote area was really eye-catching because of the very large, bigger-than- life uniform screen. This was truly one to show. The title music of the keynote was very interesting and it featured Bijoy Singhal as the model. It was interesting to talk to him afterwards, when we laughed at jokes together about his modeling assignment. TechEd India Keynote Opening Featuring Bijoy TechEd India 2010 Keynote – S. Somasegar Time: 11:15pm – 11:45pm Session 1: True Lies of SQL Server – SQL Myth Buster Following the excellent keynote, I had my very first session on the subject of SQL Server Myth Buster. At first, I was a bit nervous as right after the keynote, for this was my very first session and during my presentation I saw lots of Microsoft Product Team members. Well, it really went well and I had a really good discussion with attendees of the session. I felt that a well begin was half-done and my confidence was regained. Right after the session, I met a few of my Community friends and had meaningful discussions with them on many subjects. The abstract of the session is as follows: In this 30-minute demo session, I am going to briefly demonstrate few SQL Server Myths and their resolutions as I back them up with some demo. This demo presentation is a must-attend for all developers and administrators who would come to the event. This is going to be a very quick yet fun session. Pinal Presenting session at TechEd India 2010 Time: 1:00 PM – 2:00 PM Lunch with Somasegar After the session I went to see my daughter, and then I headed right away to the lunch with S. Somasegar – the keynote speaker and senior vice president of the Developer Division at Microsoft. I really thank to Abhishek who made it possible for us. Because of his efforts, all the MVPs had the opportunity to meet such a legendary person and had to talk with them on Microsoft Technology. Though Somasegar is currently holding such a high position in Microsoft, he is very polite and a real gentleman, and how I wish that everybody in industry is like him. Believe me, if you spread love and kindness, then that is what you will receive back. As soon as lunch time was over, I ran to the session hall as my second presentation was about to start. Time: 2:30pm – 3:30pm Session 2: Master Data Services in Microsoft SQL Server 2008 R2 Business Intelligence is a subject which was widely talked about at TechEd. Everybody was interested in this subject, and I did not excuse myself from this great concept as well. I consider myself fortunate as I was presenting on the subject of Master Data Services at TechEd. When I had initially learned this subject, I had a bit of confusion about the usage of this tool. Later on, I decided that I would tackle about how we all developers and DBAs are not able to understand something so simple such as this, and even worst, creating confusion about the technology. During system designing, it is very important to have a reference material or master lookup tables. Well, I talked about the same subject and presented the session keeping that as my center talk. The session went very well and I received lots of interesting questions. I got many compliments for talking about this subject on the real-life scenario. I really thank Rushabh Mehta (CEO, Solid Quality Mentors India) for his supportive suggestions that helped me prepare the slide deck, as well as the subject. Pinal Presenting session at TechEd India 2010 The abstract of the session is as follows: SQL Server Master Data Services will ship with SQL Server 2008 R2 and will improve Microsoft’s platform appeal. This session provides an in-depth demonstration of MDS features and highlights important usage scenarios. Master Data Services enables consistent decision-making process by allowing you to create, manage and propagate changes from a single master view of your business entities. Also, MDS – Master Data-hub which is a vital component, helps ensure the consistency of reporting across systems and deliver faster and more accurate results across the enterprise. We will talk about establishing the basis for a centralized approach to defining, deploying, and managing master data in the enterprise. Pinal Presenting session at TechEd India 2010 The day was still not over for me. I had ran into several friends but we were not able keep our enthusiasm under control about all the rumors saying that SQL Server 2008 R2 was about to be launched tomorrow in the keynote. I then ran to my third and final technical event for the day- a panel discussion with the top technologies of India. Time: 5:00pm – 6:00pm Panel Discussion: Harness the power of Web – SEO and Technical Blogging As I have delivered two technical sessions by this time, I was a bit tired but  not less enthusiastic when I had to talk about Blog and Technology. We discussed many different topics there. I told them that the most important aspect for any blog is its content. We discussed in depth the issues with plagiarism and how to avoid it. Another topic of discussion was how we technology bloggers can create awareness in the Community about what the right kind of blogging is and what morally and technically wrong acts are. A couple of questions were raised about what type of liberty a person can have in terms of writing blogs. Well, it was generically agreed that a blog is mainly a representation of our ideas and thoughts; it should not be governed by external entities. As long as one is writing what they really want to say, but not providing incorrect information or not practicing plagiarism, a blogger should be allowed to express himself. This panel discussion was supposed to be over in an hour, but the interest of the participants was remarkable and so it was extended for 30 minutes more. Finally, we decided to bring to a close the discussion and agreed that we will continue the topic next year. TechEd India Panel Discussion on Web, Technology and SEO Surprisingly, the day was just beginning after doing all of these. By this time, I have almost met all the MVP who arrived at the event, as well as many Microsoft employees. There were lots of Community folks present, too. I decided that I would go to meet several friends from the Community and continue to communicate with me on SQLAuthority.com. I also met Abhishek Baxi and had a good talk with him regarding Win Mobile and Twitter. He also took a very quick video of me wherein I spoke in my mother’s tongue, Gujarati. It was funny that I talked in Gujarati almost all the day, but when I was talking in the interview I could not find the right Gujarati words to speak. I think we all think in English when we think about Technology, so as to address universality. After meeting them, I headed towards the Speakers’ Dinner. Time: 8:00 PM – onwards Speakers Dinner The Speakers’ dinner was indeed a wonderful opportunity for all the speakers to get together and relax. We talked so many different things, from XBOX to Hindi Movies, and from SQL to Samosas. I just could not express how much fun I had. After a long evening, when I returned tmy room and met Shaivi, I just felt instantly relaxed. Kids are really gifts from God. Today was a really long but exciting day. So many things happened in just one day: Visual Studio Lanch, lunch with Somasegar, 2 technical sessions, 1 panel discussion, community leaders meeting, speakers dinner and, last but not leas,t playing with my child! A perfect day! Day 2 – April 13, 2010 Today started with a bang with the excellent keynote by Kamal Hathi who launched SQL Server 2008 R2 in India and demonstrated the power of PowerPivot to all of us. 101 Million Rows in Excel brought lots of applause from the audience. Kamal Hathi Presenting Keynote at TechEd India 2010 The day was a bit easier one for me. I had no sessions today and no events planned. I had a few meetings planned for the second day of the event. I sat in the speaker’s lounge for half a day and met many people there. I attended nearly 9 different meetings today. The subjects of the meetings were very different. Here is a list of the topics of the Community-related meetings: SQL PASS and its involvement in India and subcontinents How to start community blogging Forums and developing aptitude towards technology Ahmedabad/Gandhinagar User Groups and their developments SharePoint and SQL Business Meeting – a client meeting Business Meeting – a potential performance tuning project Business Meeting – Solid Quality Mentors (SolidQ) And family friends Pinal Dave at TechEd India The day passed by so quickly during this meeting. In the evening, I headed to Partners Expo with friends and checked out few of the booths. I really wanted to talk about some of the products, but due to the freebies there was so much crowd that I finally decided to just take the contact details of the partner. I will now start sending them with my queries and, hopefully, I will have my questions answered. Nupur and Shaivi had also one meeting to attend; it was with our family friend Vijay Raj. Vijay is also a person who loves Technology and loves it more than anybody. I see him growing and learning every day, but still remaining as a ‘human’. I believe that if someone acquires as much knowledge as him, that person will become either a computer or cyborg. Here, Vijay is still a kind gentleman and is able to stay as our close family friend. Shaivi was really happy to play with Uncle Vijay. Pinal Dave and Vijay Raj Renuka Prasad, a Microsoft MVP, impressed me with his passion and knowledge of SQL. Every time he gives me credit for his success, I believe that he is very humble. He has way more certifications than me and has worked many more years with SQL compared to me. He is an excellent photographer as well. Most of the photos in this blog post have been taken by him. I told him if ever he wants to do a part time job, he can do the photography very well. Pinal Dave and Renuka Prasad I also met L Srividya from Microsoft, whom I was looking forward to meet. She is a bundle of knowledge that everyone would surely learn a lot from her. I was able to get a few minutes from her and well, I felt confident. She enlightened me with SQL Server BI concepts, domain management and SQL Server security and few other interesting details. I also had a wonderful time talking about SharePoint with fellow Solid Quality Mentor Joy Rathnayake. He is very passionate about SharePoint but when you talk .NET and SQL with him, he is still overwhelmingly knowledgeable. In fact, while talking to him, I figured out that the recent training he delivered was on SQL Server 2008 R2. I told him a joke that it hurts my ego as he is more popular now in SQL training and consulting than me. I am sure all of you agree that working with good people is a gift from God. I am fortunate enough to work with the best of the best Industry experts. It was a great pleasure to hang out with my Community friends – Ahswin Kini, HimaBindu Vejella, Vasudev G, Suprotim Agrawal, Dhananjay, Vikram Pendse, Mahesh Dhola, Mahesh Mitkari,  Manu Zacharia, Shobhan, Hardik Shah, Ashish Mohta, Manan, Subodh Sohani and Sanjay Shetty (of course!) .  (Please let me know if I have met you at the event and forgot your name to list here). Time: 8:00 PM – onwards Community Leaders Dinner After lots of meetings, I headed towards the Community Leaders dinner meeting and met almost all the folks I met in morning. The discussion was almost the same but the real good thing was that we were enjoying it. The food was really good. Nupur was invited in the event, but Shaivi could not come. When Nupur tried to enter the event, she was stopped as Shaivi did not have the pass to enter the dinner. Nupur expressed that Shaivi is only 8 months old and does not eat outside food as well and could not stay by herself at this age, but the door keeper did not agree and asked that without the entry details Shaivi could not go in, but Nupur could. Nupur called me on phone and asked me to help her out. By the time, I was outside; the organizer of the event reached to the door and happily approved Shaivi to join the party. Once in the party, Shaivi had lots of fun meeting so many people. Shaivi Dave and Abhishek Kant Dean Guida (Infragistics President and CEO) and Pinal Dave (SQLAuthority.com) Day 3 – April 14, 2010 Though, it was last day, I was very much excited today as I was about to present my very favorite session. Query Optimization and Performance Tuning is my domain expertise and I make my leaving by consulting and training the same. Today’s session was on the same subject and as an additional twist, another subject about Spatial Database was presented. I was always intrigued with Spatial Database and I have enjoyed learning about it; however, I have never thought about Spatial Indexing before it was decided that I will do this session. I really thank Solid Quality Mentor Dr. Greg Low for his assistance in helping me prepare the slide deck and also review the content. Furthermore, today was really what I call my ‘learning day’ . So far I had not attended any session in TechEd and I felt a bit down for that. Everybody spends their valuable time & money to learn something new and exciting in TechEd and I had not attended a single session at the moment thinking that it was already last day of the event. I did have a plan for the day and I attended two technical sessions before my session of spatial database. I attended 2 sessions of Vinod Kumar. Vinod is a natural storyteller and there was no doubt that his sessions would be jam-packed. People attended his sessions simply because Vinod is syhe speaker. He did not have a single time disappointed audience; he is truly a good speaker. He knows his stuff very well. I personally do not think that in India he can be compared to anyone for SQL. Time: 12:30pm-1:30pm SQL Server Query Optimization, Execution and Debugging Query Performance I really had a fun time attending this session. Vinod made this session very interactive. The entire audience really got into the presentation and started participating in the event. Vinod was presenting a small problem with Query Tuning, which any developer would have encountered and solved with their help in such a fashion that a developer feels he or she have already resolved it. In one question, I was the only one who was ready to answer and Vinod told me in a light tone that I am now allowed to answer it! The audience really found it very amusing. There was a huge crowd around Vinod after the session. Vinod – A master storyteller! Time: 3:45pm-4:45pm Data Recovery / consistency with CheckDB This session was much heavier than the earlier one, and I must say this is my most favorite session I EVER attended in India. In this TechEd I have only attended two sessions, but in my career, I have attended numerous technical sessions not only in India, but all over the world. This session had taken my breath away. One by one, Vinod took the different databases, and started to corrupt them in different ways. Each database has some unique ways to get corrupted. Once that was done, Vinod started to show the DBCC CEHCKDB and demonstrated how it can solve your problem. He finally fixed all the databases with this single tool. I do have a good knowledge of this subject, but let me honestly admit that I have learned a lot from this session. I enjoyed and cheered during this session along with other attendees. I had total satisfaction that, just like everyone, I took advantage of the event and learned something. I am now TECHnically EDucated. Pinal Dave and Vinod Kumar After two very interactive and informative SQL Sessions from Vinod Kumar, the next turn me presenting on Spatial Database and Indexing. I got once again nervous but Vinod told me to stay natural and do my presentation. Well, once I got a huge stage with a total of four projectors and a large crowd, I felt better. Time: 5:00pm-6:00pm Session 3: Developing with SQL Server Spatial and Deep Dive into Spatial Indexing Pinal Presenting session at TechEd India 2010 Pinal Presenting session at TechEd India 2010 I kicked off this session with Michael J Swart‘s beautiful spatial image. This session was the last one for the day but, to my surprise, I had more than 200+ attendees. Slowly, the rain was starting outside and I was worried that the hall would not be full; despite this, there was not a single seat available in the first five minutes of the session. Thanks to all of you for attending my presentation. I had demonstrated the map of world (and India) and quickly explained what  Geographic and Geometry data types in Spatial Database are. This session had interesting story of Indexing and Comparison, as well as how different traditional indexes are from spatial indexing. Pinal Presenting session at TechEd India 2010 Due to the heavy rain during this event, the power went off for about 22 minutes (just an accident – nobodies fault). During these minutes, there were no audio, no video and no light. I continued to address the mass of 200+ people without any audio device and PowerPoint. I must thank the audience because not a single person left from the session. They all stayed in their place, some moved closure to listen to me properly. I noticed that the curiosity and eagerness to learn new things was at the peak even though it was the very last session of the TechEd. Everybody wanted get the maximum knowledge out of this whole event. I was touched by the support from audience. They listened and participated in my session even without any kinds of technology (no ppt, no mike, no AC, nothing). During these 22 minutes, I had completed my theory verbally. Pinal Presenting session at TechEd India 2010 After a while, we got the projector back online and we continued with some exciting demos. Many thanks to Microsoft people who worked energetically in background to get the backup power for project up. I had a very interesting demo wherein I overlaid Bangalore and Hyderabad on the India Map and find their aerial distance between them. After finding the aerial distance, we browsed online and found that SQL Server estimates the exact aerial distance between these two cities, as compared to the factual distance. There was a huge applause from the crowd on the subject that SQL Server takes into the count of the curvature of the earth and finds the precise distances based on details. During the process of finding the distance, I demonstrated a few examples of the indexes where I expressed how one can use those indexes to find these distances and how they can improve the performance of similar query. I also demonstrated few examples wherein we were able to see in which data type the Index is most useful. We finished the demos with a few more internal stuff. Pinal Presenting session at TechEd India 2010 Despite all issues, I was mostly satisfied with my presentation. I think it was the best session I have ever presented at any conference. There was no help from Technology for a while, but I still got lots of appreciation at the end. When we ended the session, the applause from the audience was so loud that for a moment, the rain was not audible. I was truly moved by the dedication of the Technology enthusiasts. Pinal Dave After Presenting session at TechEd India 2010 The abstract of the session is as follows: The Microsoft SQL Server 2008 delivers new spatial data types that enable you to consume, use, and extend location-based data through spatial-enabled applications. Attend this session to learn how to use spatial functionality in next version of SQL Server to build and optimize spatial queries. This session outlines the new geography data type to store geodetic spatial data and perform operations on it, use the new geometry data type to store planar spatial data and perform operations on it, take advantage of new spatial indexes for high performance queries, use the new spatial results tab to quickly and easily view spatial query results directly from within Management Studio, extend spatial data capabilities by building or integrating location-enabled applications through support for spatial standards and specifications and much more. Time: 8:00 PM – onwards Dinner by Sponsors After the lively session during the day, there was another dinner party courtesy of one of the sponsors of TechEd. All the MVPs and several Community leaders were present at the dinner. I would like to express my gratitude to Abhishek Kant for organizing this wonderful event for us. It was a blast and really relaxing in all angles. We all stayed there for a long time and talked about our sweet and unforgettable memories of the event. Pinal Dave and Bijoy Singhal It was really one wonderful event. After writing this much, I say that I have no words to express about how much I enjoyed TechEd. However, it is true that I shared with you only 1% of the total activities I have done at the event. There were so many people I have met, yet were not mentioned here although I wanted to write their names here, too . Anyway, I have learned so many things and up until now, I am not able to get over all the fun I had in this event. Pinal Dave at TechEd India 2010 The Next Days – April 15, 2010 – till today I am still not able to get my mind out of the whole experience I had at TechEd India 2010. It was like a whole Microsoft Family working together to celebrate a happy occasion. TechEd India – Truly An Unforgettable Experience! Reference : Pinal Dave (http://blog.SQLAuthority.com) Filed under: About Me, MVP, Pinal Dave, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Author Visit, SQLAuthority News, SQLServer, T SQL, Technology Tagged: TechEd, TechEdIn

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• SQLAuthority News – TechEd India – April 12-14, 2010 Bangalore – An Unforgettable Experience – An Op

  - by pinaldave

  TechEd India was one of the largest Technology events in India led by Microsoft. This event was attended by more than 3,000 technology enthusiasts, making it one of the most well-organized events of the year. Though I attempted to attend almost all the technology events here, I have not seen any bigger or better event in Indian subcontinents other than this. There are 21 Technical Tracks at Tech·Ed India 2010 that span more than 745 learning opportunities. I was fortunate enough to be a part of this whole event as a speaker and a delegate, as well. TechEd India Speaker Badge and A Token of Lifetime Hotel Selection I presented three different sessions at TechEd India and was also a part of panel discussion. (The details of the sessions are given at the end of this blog post.) Due to extensive traveling, I stay away from my family occasionally. For this reason, I took my wife – Nupur and daughter Shaivi (8 months old) to the event along with me. We stayed at the same hotel where the event was organized so as to maximize my time bonding with my family and to have more time in networking with technology community, at the same time. The hotel Lalit Ashok is the largest and most luxurious venue one can find in Bangalore, located in the middle of the city. The cost of the hotel was a bit pricey, but looking at all the advantages, I had decided to ask for a booking there. Hotel Lalit Ashok Nupur Dave and Shaivi Dave Arrival Day – DAY 0 – April 11, 2010 I reached the event a day earlier, and that was one wise decision for I was able to relax a bit and go over my presentation for the next day’s course. I am a kind of person who likes to get everything ready ahead of time. I was also able to enjoy a pleasant evening with several Microsoft employees and my family friends. I even checked out the location where I would be doing presentations the next day. I was fortunate enough to meet Bijoy Singhal from Microsoft who helped me out with a few of the logistics issues that occured the day before. I was not aware of the fact that the very next day he was going to be “The Man” of the TechEd 2010 event. Vinod Kumar from Microsoft was really very kind as he talked to me regarding my subsequent session. He gave me some suggestions which were really helpful that I was able to incorporate them during my presentation. Finally, I was able to meet Abhishek Kant from Microsoft; his valuable suggestions and unlimited passion have inspired many people like me to work with the Community. Pradipta from Microsoft was also around, being extremely busy with logistics; however, in those busy times, he did find some good spare time to have a chat with me and the other Community leaders. I also met Harish Ranganathan and Sachin Rathi, both from Microsoft. It was so interesting to listen to both of them talking about SharePoint. I just have no words to express my overwhelmed spirit because of all these passionate young guys - Pradipta,Vinod, Bijoy, Harish, Sachin and Ahishek (of course!). Map of TechEd India 2010 Event Day 1 – April 12, 2010 From morning until night time, today was truly a very busy day for me. I had two presentations and one panel discussion for the day. Needless to say, I had a few meetings to attend as well. The day started with a keynote from S. Somaseger where he announced the launch of Visual Studio 2010. The keynote area was really eye-catching because of the very large, bigger-than- life uniform screen. This was truly one to show. The title music of the keynote was very interesting and it featured Bijoy Singhal as the model. It was interesting to talk to him afterwards, when we laughed at jokes together about his modeling assignment. TechEd India Keynote Opening Featuring Bijoy TechEd India 2010 Keynote – S. Somasegar Time: 11:15pm – 11:45pm Session 1: True Lies of SQL Server – SQL Myth Buster Following the excellent keynote, I had my very first session on the subject of SQL Server Myth Buster. At first, I was a bit nervous as right after the keynote, for this was my very first session and during my presentation I saw lots of Microsoft Product Team members. Well, it really went well and I had a really good discussion with attendees of the session. I felt that a well begin was half-done and my confidence was regained. Right after the session, I met a few of my Community friends and had meaningful discussions with them on many subjects. The abstract of the session is as follows: In this 30-minute demo session, I am going to briefly demonstrate few SQL Server Myths and their resolutions as I back them up with some demo. This demo presentation is a must-attend for all developers and administrators who would come to the event. This is going to be a very quick yet fun session. Pinal Presenting session at TechEd India 2010 Time: 1:00 PM – 2:00 PM Lunch with Somasegar After the session I went to see my daughter, and then I headed right away to the lunch with S. Somasegar – the keynote speaker and senior vice president of the Developer Division at Microsoft. I really thank to Abhishek who made it possible for us. Because of his efforts, all the MVPs had the opportunity to meet such a legendary person and had to talk with them on Microsoft Technology. Though Somasegar is currently holding such a high position in Microsoft, he is very polite and a real gentleman, and how I wish that everybody in industry is like him. Believe me, if you spread love and kindness, then that is what you will receive back. As soon as lunch time was over, I ran to the session hall as my second presentation was about to start. Time: 2:30pm – 3:30pm Session 2: Master Data Services in Microsoft SQL Server 2008 R2 Business Intelligence is a subject which was widely talked about at TechEd. Everybody was interested in this subject, and I did not excuse myself from this great concept as well. I consider myself fortunate as I was presenting on the subject of Master Data Services at TechEd. When I had initially learned this subject, I had a bit of confusion about the usage of this tool. Later on, I decided that I would tackle about how we all developers and DBAs are not able to understand something so simple such as this, and even worst, creating confusion about the technology. During system designing, it is very important to have a reference material or master lookup tables. Well, I talked about the same subject and presented the session keeping that as my center talk. The session went very well and I received lots of interesting questions. I got many compliments for talking about this subject on the real-life scenario. I really thank Rushabh Mehta (CEO, Solid Quality Mentors India) for his supportive suggestions that helped me prepare the slide deck, as well as the subject. Pinal Presenting session at TechEd India 2010 The abstract of the session is as follows: SQL Server Master Data Services will ship with SQL Server 2008 R2 and will improve Microsoft’s platform appeal. This session provides an in-depth demonstration of MDS features and highlights important usage scenarios. Master Data Services enables consistent decision-making process by allowing you to create, manage and propagate changes from a single master view of your business entities. Also, MDS – Master Data-hub which is a vital component, helps ensure the consistency of reporting across systems and deliver faster and more accurate results across the enterprise. We will talk about establishing the basis for a centralized approach to defining, deploying, and managing master data in the enterprise. Pinal Presenting session at TechEd India 2010 The day was still not over for me. I had ran into several friends but we were not able keep our enthusiasm under control about all the rumors saying that SQL Server 2008 R2 was about to be launched tomorrow in the keynote. I then ran to my third and final technical event for the day- a panel discussion with the top technologies of India. Time: 5:00pm – 6:00pm Panel Discussion: Harness the power of Web – SEO and Technical Blogging As I have delivered two technical sessions by this time, I was a bit tired but  not less enthusiastic when I had to talk about Blog and Technology. We discussed many different topics there. I told them that the most important aspect for any blog is its content. We discussed in depth the issues with plagiarism and how to avoid it. Another topic of discussion was how we technology bloggers can create awareness in the Community about what the right kind of blogging is and what morally and technically wrong acts are. A couple of questions were raised about what type of liberty a person can have in terms of writing blogs. Well, it was generically agreed that a blog is mainly a representation of our ideas and thoughts; it should not be governed by external entities. As long as one is writing what they really want to say, but not providing incorrect information or not practicing plagiarism, a blogger should be allowed to express himself. This panel discussion was supposed to be over in an hour, but the interest of the participants was remarkable and so it was extended for 30 minutes more. Finally, we decided to bring to a close the discussion and agreed that we will continue the topic next year. TechEd India Panel Discussion on Web, Technology and SEO Surprisingly, the day was just beginning after doing all of these. By this time, I have almost met all the MVP who arrived at the event, as well as many Microsoft employees. There were lots of Community folks present, too. I decided that I would go to meet several friends from the Community and continue to communicate with me on SQLAuthority.com. I also met Abhishek Baxi and had a good talk with him regarding Win Mobile and Twitter. He also took a very quick video of me wherein I spoke in my mother’s tongue, Gujarati. It was funny that I talked in Gujarati almost all the day, but when I was talking in the interview I could not find the right Gujarati words to speak. I think we all think in English when we think about Technology, so as to address universality. After meeting them, I headed towards the Speakers’ Dinner. Time: 8:00 PM – onwards Speakers Dinner The Speakers’ dinner was indeed a wonderful opportunity for all the speakers to get together and relax. We talked so many different things, from XBOX to Hindi Movies, and from SQL to Samosas. I just could not express how much fun I had. After a long evening, when I returned tmy room and met Shaivi, I just felt instantly relaxed. Kids are really gifts from God. Today was a really long but exciting day. So many things happened in just one day: Visual Studio Lanch, lunch with Somasegar, 2 technical sessions, 1 panel discussion, community leaders meeting, speakers dinner and, last but not leas,t playing with my child! A perfect day! Day 2 – April 13, 2010 Today started with a bang with the excellent keynote by Kamal Hathi who launched SQL Server 2008 R2 in India and demonstrated the power of PowerPivot to all of us. 101 Million Rows in Excel brought lots of applause from the audience. Kamal Hathi Presenting Keynote at TechEd India 2010 The day was a bit easier one for me. I had no sessions today and no events planned. I had a few meetings planned for the second day of the event. I sat in the speaker’s lounge for half a day and met many people there. I attended nearly 9 different meetings today. The subjects of the meetings were very different. Here is a list of the topics of the Community-related meetings: SQL PASS and its involvement in India and subcontinents How to start community blogging Forums and developing aptitude towards technology Ahmedabad/Gandhinagar User Groups and their developments SharePoint and SQL Business Meeting – a client meeting Business Meeting – a potential performance tuning project Business Meeting – Solid Quality Mentors (SolidQ) And family friends Pinal Dave at TechEd India The day passed by so quickly during this meeting. In the evening, I headed to Partners Expo with friends and checked out few of the booths. I really wanted to talk about some of the products, but due to the freebies there was so much crowd that I finally decided to just take the contact details of the partner. I will now start sending them with my queries and, hopefully, I will have my questions answered. Nupur and Shaivi had also one meeting to attend; it was with our family friend Vijay Raj. Vijay is also a person who loves Technology and loves it more than anybody. I see him growing and learning every day, but still remaining as a ‘human’. I believe that if someone acquires as much knowledge as him, that person will become either a computer or cyborg. Here, Vijay is still a kind gentleman and is able to stay as our close family friend. Shaivi was really happy to play with Uncle Vijay. Pinal Dave and Vijay Raj Renuka Prasad, a Microsoft MVP, impressed me with his passion and knowledge of SQL. Every time he gives me credit for his success, I believe that he is very humble. He has way more certifications than me and has worked many more years with SQL compared to me. He is an excellent photographer as well. Most of the photos in this blog post have been taken by him. I told him if ever he wants to do a part time job, he can do the photography very well. Pinal Dave and Renuka Prasad I also met L Srividya from Microsoft, whom I was looking forward to meet. She is a bundle of knowledge that everyone would surely learn a lot from her. I was able to get a few minutes from her and well, I felt confident. She enlightened me with SQL Server BI concepts, domain management and SQL Server security and few other interesting details. I also had a wonderful time talking about SharePoint with fellow Solid Quality Mentor Joy Rathnayake. He is very passionate about SharePoint but when you talk .NET and SQL with him, he is still overwhelmingly knowledgeable. In fact, while talking to him, I figured out that the recent training he delivered was on SQL Server 2008 R2. I told him a joke that it hurts my ego as he is more popular now in SQL training and consulting than me. I am sure all of you agree that working with good people is a gift from God. I am fortunate enough to work with the best of the best Industry experts. It was a great pleasure to hang out with my Community friends – Ahswin Kini, HimaBindu Vejella, Vasudev G, Suprotim Agrawal, Dhananjay, Vikram Pendse, Mahesh Dhola, Mahesh Mitkari,  Manu Zacharia, Shobhan, Hardik Shah, Ashish Mohta, Manan, Subodh Sohani and Sanjay Shetty (of course!) .  (Please let me know if I have met you at the event and forgot your name to list here). Time: 8:00 PM – onwards Community Leaders Dinner After lots of meetings, I headed towards the Community Leaders dinner meeting and met almost all the folks I met in morning. The discussion was almost the same but the real good thing was that we were enjoying it. The food was really good. Nupur was invited in the event, but Shaivi could not come. When Nupur tried to enter the event, she was stopped as Shaivi did not have the pass to enter the dinner. Nupur expressed that Shaivi is only 8 months old and does not eat outside food as well and could not stay by herself at this age, but the door keeper did not agree and asked that without the entry details Shaivi could not go in, but Nupur could. Nupur called me on phone and asked me to help her out. By the time, I was outside; the organizer of the event reached to the door and happily approved Shaivi to join the party. Once in the party, Shaivi had lots of fun meeting so many people. Shaivi Dave and Abhishek Kant Dean Guida (Infragistics President and CEO) and Pinal Dave (SQLAuthority.com) Day 3 – April 14, 2010 Though, it was last day, I was very much excited today as I was about to present my very favorite session. Query Optimization and Performance Tuning is my domain expertise and I make my leaving by consulting and training the same. Today’s session was on the same subject and as an additional twist, another subject about Spatial Database was presented. I was always intrigued with Spatial Database and I have enjoyed learning about it; however, I have never thought about Spatial Indexing before it was decided that I will do this session. I really thank Solid Quality Mentor Dr. Greg Low for his assistance in helping me prepare the slide deck and also review the content. Furthermore, today was really what I call my ‘learning day’ . So far I had not attended any session in TechEd and I felt a bit down for that. Everybody spends their valuable time & money to learn something new and exciting in TechEd and I had not attended a single session at the moment thinking that it was already last day of the event. I did have a plan for the day and I attended two technical sessions before my session of spatial database. I attended 2 sessions of Vinod Kumar. Vinod is a natural storyteller and there was no doubt that his sessions would be jam-packed. People attended his sessions simply because Vinod is syhe speaker. He did not have a single time disappointed audience; he is truly a good speaker. He knows his stuff very well. I personally do not think that in India he can be compared to anyone for SQL. Time: 12:30pm-1:30pm SQL Server Query Optimization, Execution and Debugging Query Performance I really had a fun time attending this session. Vinod made this session very interactive. The entire audience really got into the presentation and started participating in the event. Vinod was presenting a small problem with Query Tuning, which any developer would have encountered and solved with their help in such a fashion that a developer feels he or she have already resolved it. In one question, I was the only one who was ready to answer and Vinod told me in a light tone that I am now allowed to answer it! The audience really found it very amusing. There was a huge crowd around Vinod after the session. Vinod – A master storyteller! Time: 3:45pm-4:45pm Data Recovery / consistency with CheckDB This session was much heavier than the earlier one, and I must say this is my most favorite session I EVER attended in India. In this TechEd I have only attended two sessions, but in my career, I have attended numerous technical sessions not only in India, but all over the world. This session had taken my breath away. One by one, Vinod took the different databases, and started to corrupt them in different ways. Each database has some unique ways to get corrupted. Once that was done, Vinod started to show the DBCC CEHCKDB and demonstrated how it can solve your problem. He finally fixed all the databases with this single tool. I do have a good knowledge of this subject, but let me honestly admit that I have learned a lot from this session. I enjoyed and cheered during this session along with other attendees. I had total satisfaction that, just like everyone, I took advantage of the event and learned something. I am now TECHnically EDucated. Pinal Dave and Vinod Kumar After two very interactive and informative SQL Sessions from Vinod Kumar, the next turn me presenting on Spatial Database and Indexing. I got once again nervous but Vinod told me to stay natural and do my presentation. Well, once I got a huge stage with a total of four projectors and a large crowd, I felt better. Time: 5:00pm-6:00pm Session 3: Developing with SQL Server Spatial and Deep Dive into Spatial Indexing Pinal Presenting session at TechEd India 2010 Pinal Presenting session at TechEd India 2010 I kicked off this session with Michael J Swart‘s beautiful spatial image. This session was the last one for the day but, to my surprise, I had more than 200+ attendees. Slowly, the rain was starting outside and I was worried that the hall would not be full; despite this, there was not a single seat available in the first five minutes of the session. Thanks to all of you for attending my presentation. I had demonstrated the map of world (and India) and quickly explained what  Geographic and Geometry data types in Spatial Database are. This session had interesting story of Indexing and Comparison, as well as how different traditional indexes are from spatial indexing. Pinal Presenting session at TechEd India 2010 Due to the heavy rain during this event, the power went off for about 22 minutes (just an accident – nobodies fault). During these minutes, there were no audio, no video and no light. I continued to address the mass of 200+ people without any audio device and PowerPoint. I must thank the audience because not a single person left from the session. They all stayed in their place, some moved closure to listen to me properly. I noticed that the curiosity and eagerness to learn new things was at the peak even though it was the very last session of the TechEd. Everybody wanted get the maximum knowledge out of this whole event. I was touched by the support from audience. They listened and participated in my session even without any kinds of technology (no ppt, no mike, no AC, nothing). During these 22 minutes, I had completed my theory verbally. Pinal Presenting session at TechEd India 2010 After a while, we got the projector back online and we continued with some exciting demos. Many thanks to Microsoft people who worked energetically in background to get the backup power for project up. I had a very interesting demo wherein I overlaid Bangalore and Hyderabad on the India Map and find their aerial distance between them. After finding the aerial distance, we browsed online and found that SQL Server estimates the exact aerial distance between these two cities, as compared to the factual distance. There was a huge applause from the crowd on the subject that SQL Server takes into the count of the curvature of the earth and finds the precise distances based on details. During the process of finding the distance, I demonstrated a few examples of the indexes where I expressed how one can use those indexes to find these distances and how they can improve the performance of similar query. I also demonstrated few examples wherein we were able to see in which data type the Index is most useful. We finished the demos with a few more internal stuff. Pinal Presenting session at TechEd India 2010 Despite all issues, I was mostly satisfied with my presentation. I think it was the best session I have ever presented at any conference. There was no help from Technology for a while, but I still got lots of appreciation at the end. When we ended the session, the applause from the audience was so loud that for a moment, the rain was not audible. I was truly moved by the dedication of the Technology enthusiasts. Pinal Dave After Presenting session at TechEd India 2010 The abstract of the session is as follows: The Microsoft SQL Server 2008 delivers new spatial data types that enable you to consume, use, and extend location-based data through spatial-enabled applications. Attend this session to learn how to use spatial functionality in next version of SQL Server to build and optimize spatial queries. This session outlines the new geography data type to store geodetic spatial data and perform operations on it, use the new geometry data type to store planar spatial data and perform operations on it, take advantage of new spatial indexes for high performance queries, use the new spatial results tab to quickly and easily view spatial query results directly from within Management Studio, extend spatial data capabilities by building or integrating location-enabled applications through support for spatial standards and specifications and much more. Time: 8:00 PM – onwards Dinner by Sponsors After the lively session during the day, there was another dinner party courtesy of one of the sponsors of TechEd. All the MVPs and several Community leaders were present at the dinner. I would like to express my gratitude to Abhishek Kant for organizing this wonderful event for us. It was a blast and really relaxing in all angles. We all stayed there for a long time and talked about our sweet and unforgettable memories of the event. Pinal Dave and Bijoy Singhal It was really one wonderful event. After writing this much, I say that I have no words to express about how much I enjoyed TechEd. However, it is true that I shared with you only 1% of the total activities I have done at the event. There were so many people I have met, yet were not mentioned here although I wanted to write their names here, too . Anyway, I have learned so many things and up until now, I am not able to get over all the fun I had in this event. Pinal Dave at TechEd India 2010 The Next Days – April 15, 2010 – till today I am still not able to get my mind out of the whole experience I had at TechEd India 2010. It was like a whole Microsoft Family working together to celebrate a happy occasion. TechEd India – Truly An Unforgettable Experience! Reference : Pinal Dave (http://blog.SQLAuthority.com) Filed under: About Me, MVP, Pinal Dave, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Author Visit, SQLAuthority News, SQLServer, T SQL, Technology Tagged: TechEd, TechEdIn

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• Node.js Adventure - When Node Flying in Wind

  - by Shaun

  In the first post of this series I mentioned some popular modules in the community, such as underscore, async, etc.. I also listed a module named “Wind (zh-CN)”, which is created by one of my friend, Jeff Zhao (zh-CN). Now I would like to use a separated post to introduce this module since I feel it brings a new async programming style in not only Node.js but JavaScript world. If you know or heard about the new feature in C# 5.0 called “async and await”, or you learnt F#, you will find the “Wind” brings the similar async programming experience in JavaScript. By using “Wind”, we can write async code that looks like the sync code. The callbacks, async stats and exceptions will be handled by “Wind” automatically and transparently.   What’s the Problem: Dense “Callback” Phobia Let’s firstly back to my second post in this series. As I mentioned in that post, when we wanted to read some records from SQL Server we need to open the database connection, and then execute the query. In Node.js all IO operation are designed as async callback pattern which means when the operation was done, it will invoke a function which was taken from the last parameter. For example the database connection opening code would be like this. 1: sql.open(connectionString, function(error, conn) { 2: if(error) { 3: // some error handling code 4: } 5: else { 6: // connection opened successfully 7: } 8: }); And then if we need to query the database the code would be like this. It nested in the previous function. 1: sql.open(connectionString, function(error, conn) { 2: if(error) { 3: // some error handling code 4: } 5: else { 6: // connection opened successfully 7: conn.queryRaw(command, function(error, results) { 8: if(error) { 9: // failed to execute this command 10: } 11: else { 12: // records retrieved successfully 13: } 14: }; 15: } 16: }); Assuming if we need to copy some data from this database to another then we need to open another connection and execute the command within the function under the query function. 1: sql.open(connectionString, function(error, conn) { 2: if(error) { 3: // some error handling code 4: } 5: else { 6: // connection opened successfully 7: conn.queryRaw(command, function(error, results) { 8: if(error) { 9: // failed to execute this command 10: } 11: else { 12: // records retrieved successfully 13: target.open(targetConnectionString, function(error, t_conn) { 14: if(error) { 15: // connect failed 16: } 17: else { 18: t_conn.queryRaw(copy_command, function(error, results) { 19: if(error) { 20: // copy failed 21: } 22: else { 23: // and then, what do you want to do now... 24: } 25: }; 26: } 27: }; 28: } 29: }; 30: } 31: }); This is just an example. In the real project the logic would be more complicated. This means our application might be messed up and the business process will be fragged by many callback functions. I would like call this “Dense Callback Phobia”. This might be a challenge how to make code straightforward and easy to read, something like below. 1: try 2: { 3: // open source connection 4: var s_conn = sqlConnect(s_connectionString); 5: // retrieve data 6: var results = sqlExecuteCommand(s_conn, s_command); 7: 8: // open target connection 9: var t_conn = sqlConnect(t_connectionString); 10: // prepare the copy command 11: var t_command = getCopyCommand(results); 12: // execute the copy command 13: sqlExecuteCommand(s_conn, t_command); 14: } 15: catch (ex) 16: { 17: // error handling 18: }   What’s the Problem: Sync-styled Async Programming Similar as the previous problem, the callback-styled async programming model makes the upcoming operation as a part of the current operation, and mixed with the error handling code. So it’s very hard to understand what on earth this code will do. And since Node.js utilizes non-blocking IO mode, we cannot invoke those operations one by one, as they will be executed concurrently. For example, in this post when I tried to copy the records from Windows Azure SQL Database (a.k.a. WASD) to Windows Azure Table Storage, if I just insert the data into table storage one by one and then print the “Finished” message, I will see the message shown before the data had been copied. This is because all operations were executed at the same time. In order to make the copy operation and print operation executed synchronously I introduced a module named “async” and the code was changed as below. 1: async.forEach(results.rows, 2: function (row, callback) { 3: var resource = { 4: "PartitionKey": row[1], 5: "RowKey": row[0], 6: "Value": row[2] 7: }; 8: client.insertEntity(tableName, resource, function (error) { 9: if (error) { 10: callback(error); 11: } 12: else { 13: console.log("entity inserted."); 14: callback(null); 15: } 16: }); 17: }, 18: function (error) { 19: if (error) { 20: error["target"] = "insertEntity"; 21: res.send(500, error); 22: } 23: else { 24: console.log("all done."); 25: res.send(200, "Done!"); 26: } 27: }); It ensured that the “Finished” message will be printed when all table entities had been inserted. But it cannot promise that the records will be inserted in sequence. It might be another challenge to make the code looks like in sync-style? 1: try 2: { 3: forEach(row in rows) { 4: var entity = { /* ... */ }; 5: tableClient.insert(tableName, entity); 6: } 7:  8: console.log("Finished"); 9: } 10: catch (ex) { 11: console.log(ex); 12: }   How “Wind” Helps “Wind” is a JavaScript library which provides the control flow with plain JavaScript for asynchronous programming (and more) without additional pre-compiling steps. It’s available in NPM so that we can install it through “npm install wind”. Now let’s create a very simple Node.js application as the example. This application will take some website URLs from the command arguments and tried to retrieve the body length and print them in console. Then at the end print “Finish”. I’m going to use “request” module to make the HTTP call simple so I also need to install by the command “npm install request”. The code would be like this. 1: var request = require("request"); 2:  3: // get the urls from arguments, the first two arguments are `node.exe` and `fetch.js` 4: var args = process.argv.splice(2); 5:  6: // main function 7: var main = function() { 8: for(var i = 0; i < args.length; i++) { 9: // get the url 10: var url = args[i]; 11: // send the http request and try to get the response and body 12: request(url, function(error, response, body) { 13: if(!error && response.statusCode == 200) { 14: // log the url and the body length 15: console.log( 16: "%s: %d.", 17: response.request.uri.href, 18: body.length); 19: } 20: else { 21: // log error 22: console.log(error); 23: } 24: }); 25: } 26: 27: // finished 28: console.log("Finished"); 29: }; 30:  31: // execute the main function 32: main(); Let’s execute this application. (I made them in multi-lines for better reading.) 1: node fetch.js 2: "http://www.igt.com/us-en.aspx" 3: "http://www.igt.com/us-en/games.aspx" 4: "http://www.igt.com/us-en/cabinets.aspx" 5: "http://www.igt.com/us-en/systems.aspx" 6: "http://www.igt.com/us-en/interactive.aspx" 7: "http://www.igt.com/us-en/social-gaming.aspx" 8: "http://www.igt.com/support.aspx" Below is the output. As you can see the finish message was printed at the beginning, and the pages’ length retrieved in a different order than we specified. This is because in this code the request command, console logging command are executed asynchronously and concurrently. Now let’s introduce “Wind” to make them executed in order, which means it will request the websites one by one, and print the message at the end.   First of all we need to import the “Wind” package and make sure the there’s only one global variant named “Wind”, and ensure it’s “Wind” instead of “wind”. 1: var Wind = require("wind");   Next, we need to tell “Wind” which code will be executed asynchronously so that “Wind” can control the execution process. In this case the “request” operation executed asynchronously so we will create a “Task” by using a build-in helps function in “Wind” named Wind.Async.Task.create. 1: var requestBodyLengthAsync = function(url) { 2: return Wind.Async.Task.create(function(t) { 3: request(url, function(error, response, body) { 4: if(error || response.statusCode != 200) { 5: t.complete("failure", error); 6: } 7: else { 8: var data = 9: { 10: uri: response.request.uri.href, 11: length: body.length 12: }; 13: t.complete("success", data); 14: } 15: }); 16: }); 17: }; The code above created a “Task” from the original request calling code. In “Wind” a “Task” means an operation will be finished in some time in the future. A “Task” can be started by invoke its start() method, but no one knows when it actually will be finished. The Wind.Async.Task.create helped us to create a task. The only parameter is a function where we can put the actual operation in, and then notify the task object it’s finished successfully or failed by using the complete() method. In the code above I invoked the request method. If it retrieved the response successfully I set the status of this task as “success” with the URL and body length. If it failed I set this task as “failure” and pass the error out.   Next, we will change the main() function. In “Wind” if we want a function can be controlled by Wind we need to mark it as “async”. This should be done by using the code below. 1: var main = eval(Wind.compile("async", function() { 2: })); When the application is running, Wind will detect “eval(Wind.compile(“async”, function” and generate an anonymous code from the body of this original function. Then the application will run the anonymous code instead of the original one. In our example the main function will be like this. 1: var main = eval(Wind.compile("async", function() { 2: for(var i = 0; i < args.length; i++) { 3: try 4: { 5: var result = $await(requestBodyLengthAsync(args[i])); 6: console.log( 7: "%s: %d.", 8: result.uri, 9: result.length); 10: } 11: catch (ex) { 12: console.log(ex); 13: } 14: } 15: 16: console.log("Finished"); 17: })); As you can see, when I tried to request the URL I use a new command named “$await”. It tells Wind, the operation next to $await will be executed asynchronously, and the main thread should be paused until it finished (or failed). So in this case, my application will be pause when the first response was received, and then print its body length, then try the next one. At the end, print the finish message.   Finally, execute the main function. The full code would be like this. 1: var request = require("request"); 2: var Wind = require("wind"); 3:  4: var args = process.argv.splice(2); 5:  6: var requestBodyLengthAsync = function(url) { 7: return Wind.Async.Task.create(function(t) { 8: request(url, function(error, response, body) { 9: if(error || response.statusCode != 200) { 10: t.complete("failure", error); 11: } 12: else { 13: var data = 14: { 15: uri: response.request.uri.href, 16: length: body.length 17: }; 18: t.complete("success", data); 19: } 20: }); 21: }); 22: }; 23:  24: var main = eval(Wind.compile("async", function() { 25: for(var i = 0; i < args.length; i++) { 26: try 27: { 28: var result = $await(requestBodyLengthAsync(args[i])); 29: console.log( 30: "%s: %d.", 31: result.uri, 32: result.length); 33: } 34: catch (ex) { 35: console.log(ex); 36: } 37: } 38: 39: console.log("Finished"); 40: })); 41:  42: main().start();   Run our new application. At the beginning we will see the compiled and generated code by Wind. Then we can see the pages were requested one by one, and at the end the finish message was printed. Below is the code Wind generated for us. As you can see the original code, the output code were shown. 1: // Original: 2: function () { 3: for(var i = 0; i < args.length; i++) { 4: try 5: { 6: var result = $await(requestBodyLengthAsync(args[i])); 7: console.log( 8: "%s: %d.", 9: result.uri, 10: result.length); 11: } 12: catch (ex) { 13: console.log(ex); 14: } 15: } 16: 17: console.log("Finished"); 18: } 19:  20: // Compiled: 21: /* async << function () { */ (function () { 22: var _builder_$0 = Wind.builders["async"]; 23: return _builder_$0.Start(this, 24: _builder_$0.Combine( 25: _builder_$0.Delay(function () { 26: /* var i = 0; */ var i = 0; 27: /* for ( */ return _builder_$0.For(function () { 28: /* ; i < args.length */ return i < args.length; 29: }, function () { 30: /* ; i ++) { */ i ++; 31: }, 32: /* try { */ _builder_$0.Try( 33: _builder_$0.Delay(function () { 34: /* var result = $await(requestBodyLengthAsync(args[i])); */ return _builder_$0.Bind(requestBodyLengthAsync(args[i]), function (result) { 35: /* console.log("%s: %d.", result.uri, result.length); */ console.log("%s: %d.", result.uri, result.length); 36: return _builder_$0.Normal(); 37: }); 38: }), 39: /* } catch (ex) { */ function (ex) { 40: /* console.log(ex); */ console.log(ex); 41: return _builder_$0.Normal(); 42: /* } */ }, 43: null 44: ) 45: /* } */ ); 46: }), 47: _builder_$0.Delay(function () { 48: /* console.log("Finished"); */ console.log("Finished"); 49: return _builder_$0.Normal(); 50: }) 51: ) 52: ); 53: /* } */ })   How Wind Works Someone may raise a big concern when you find I utilized “eval” in my code. Someone may assume that Wind utilizes “eval” to execute some code dynamically while “eval” is very low performance. But I would say, Wind does NOT use “eval” to run the code. It only use “eval” as a flag to know which code should be compiled at runtime. When the code was firstly been executed, Wind will check and find “eval(Wind.compile(“async”, function”. So that it knows this function should be compiled. Then it utilized parse-js to analyze the inner JavaScript and generated the anonymous code in memory. Then it rewrite the original code so that when the application was running it will use the anonymous one instead of the original one. Since the code generation was done at the beginning of the application was started, in the future no matter how long our application runs and how many times the async function was invoked, it will use the generated code, no need to generate again. So there’s no significant performance hurt when using Wind.   Wind in My Previous Demo Let’s adopt Wind into one of my previous demonstration and to see how it helps us to make our code simple, straightforward and easy to read and understand. In this post when I implemented the functionality that copied the records from my WASD to table storage, the logic would be like this. 1, Open database connection. 2, Execute a query to select all records from the table. 3, Recreate the table in Windows Azure table storage. 4, Create entities from each of the records retrieved previously, and then insert them into table storage. 5, Finally, show message as the HTTP response. But as the image below, since there are so many callbacks and async operations, it’s very hard to understand my logic from the code. Now let’s use Wind to rewrite our code. First of all, of course, we need the Wind package. Then we need to include the package files into project and mark them as “Copy always”. Add the Wind package into the source code. Pay attention to the variant name, you must use “Wind” instead of “wind”. 1: var express = require("express"); 2: var async = require("async"); 3: var sql = require("node-sqlserver"); 4: var azure = require("azure"); 5: var Wind = require("wind"); Now we need to create some async functions by using Wind. All async functions should be wrapped so that it can be controlled by Wind which are open database, retrieve records, recreate table (delete and create) and insert entity in table. Below are these new functions. All of them are created by using Wind.Async.Task.create. 1: sql.openAsync = function (connectionString) { 2: return Wind.Async.Task.create(function (t) { 3: sql.open(connectionString, function (error, conn) { 4: if (error) { 5: t.complete("failure", error); 6: } 7: else { 8: t.complete("success", conn); 9: } 10: }); 11: }); 12: }; 13:  14: sql.queryAsync = function (conn, query) { 15: return Wind.Async.Task.create(function (t) { 16: conn.queryRaw(query, function (error, results) { 17: if (error) { 18: t.complete("failure", error); 19: } 20: else { 21: t.complete("success", results); 22: } 23: }); 24: }); 25: }; 26:  27: azure.recreateTableAsync = function (tableName) { 28: return Wind.Async.Task.create(function (t) { 29: client.deleteTable(tableName, function (error, successful, response) { 30: console.log("delete table finished"); 31: client.createTableIfNotExists(tableName, function (error, successful, response) { 32: console.log("create table finished"); 33: if (error) { 34: t.complete("failure", error); 35: } 36: else { 37: t.complete("success", null); 38: } 39: }); 40: }); 41: }); 42: }; 43:  44: azure.insertEntityAsync = function (tableName, entity) { 45: return Wind.Async.Task.create(function (t) { 46: client.insertEntity(tableName, entity, function (error, entity, response) { 47: if (error) { 48: t.complete("failure", error); 49: } 50: else { 51: t.complete("success", null); 52: } 53: }); 54: }); 55: }; Then in order to use these functions we will create a new function which contains all steps for data copying. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: } 4: catch (ex) { 5: console.log(ex); 6: res.send(500, "Internal error."); 7: } 8: })); Let’s execute steps one by one with the “$await” keyword introduced by Wind so that it will be invoked in sequence. First is to open the database connection. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: } 7: catch (ex) { 8: console.log(ex); 9: res.send(500, "Internal error."); 10: } 11: })); Then retrieve all records from the database connection. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: // retrieve all records from database 7: var results = $await(sql.queryAsync(conn, "SELECT * FROM [Resource]")); 8: console.log("records selected. count = %d", results.rows.length); 9: } 10: catch (ex) { 11: console.log(ex); 12: res.send(500, "Internal error."); 13: } 14: })); After recreated the table, we need to create the entities and insert them into table storage. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: // retrieve all records from database 7: var results = $await(sql.queryAsync(conn, "SELECT * FROM [Resource]")); 8: console.log("records selected. count = %d", results.rows.length); 9: if (results.rows.length > 0) { 10: // recreate the table 11: $await(azure.recreateTableAsync(tableName)); 12: console.log("table created"); 13: // insert records in table storage one by one 14: for (var i = 0; i < results.rows.length; i++) { 15: var entity = { 16: "PartitionKey": results.rows[i][1], 17: "RowKey": results.rows[i][0], 18: "Value": results.rows[i][2] 19: }; 20: $await(azure.insertEntityAsync(tableName, entity)); 21: console.log("entity inserted"); 22: } 23: } 24: } 25: catch (ex) { 26: console.log(ex); 27: res.send(500, "Internal error."); 28: } 29: })); Finally, send response back to the browser. 1: var copyRecords = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: // retrieve all records from database 7: var results = $await(sql.queryAsync(conn, "SELECT * FROM [Resource]")); 8: console.log("records selected. count = %d", results.rows.length); 9: if (results.rows.length > 0) { 10: // recreate the table 11: $await(azure.recreateTableAsync(tableName)); 12: console.log("table created"); 13: // insert records in table storage one by one 14: for (var i = 0; i < results.rows.length; i++) { 15: var entity = { 16: "PartitionKey": results.rows[i][1], 17: "RowKey": results.rows[i][0], 18: "Value": results.rows[i][2] 19: }; 20: $await(azure.insertEntityAsync(tableName, entity)); 21: console.log("entity inserted"); 22: } 23: // send response 24: console.log("all done"); 25: res.send(200, "All done!"); 26: } 27: } 28: catch (ex) { 29: console.log(ex); 30: res.send(500, "Internal error."); 31: } 32: })); If we compared with the previous code we will find now it became more readable and much easy to understand. It’s very easy to know what this function does even though without any comments. When user go to URL “/was/copyRecords” we will execute the function above. The code would be like this. 1: app.get("/was/copyRecords", function (req, res) { 2: copyRecords(req, res).start(); 3: }); And below is the logs printed in local compute emulator console. As we can see the functions executed one by one and then finally the response back to me browser.   Scaffold Functions in Wind Wind provides not only the async flow control and compile functions, but many scaffold methods as well. We can build our async code more easily by using them. I’m going to introduce some basic scaffold functions here. In the code above I created some functions which wrapped from the original async function such as open database, create table, etc.. All of them are very similar, created a task by using Wind.Async.Task.create, return error or result object through Task.complete function. In fact, Wind provides some functions for us to create task object from the original async functions. If the original async function only has a callback parameter, we can use Wind.Async.Binding.fromCallback method to get the task object directly. For example the code below returned the task object which wrapped the file exist check function. 1: var Wind = require("wind"); 2: var fs = require("fs"); 3:  4: fs.existsAsync = Wind.Async.Binding.fromCallback(fs.exists); In Node.js a very popular async function pattern is that, the first parameter in the callback function represent the error object, and the other parameters is the return values. In this case we can use another build-in function in Wind named Wind.Async.Binding.fromStandard. For example, the open database function can be created from the code below. 1: sql.openAsync = Wind.Async.Binding.fromStandard(sql.open); 2:  3: /* 4: sql.openAsync = function (connectionString) { 5: return Wind.Async.Task.create(function (t) { 6: sql.open(connectionString, function (error, conn) { 7: if (error) { 8: t.complete("failure", error); 9: } 10: else { 11: t.complete("success", conn); 12: } 13: }); 14: }); 15: }; 16: */ When I was testing the scaffold functions under Wind.Async.Binding I found for some functions, such as the Azure SDK insert entity function, cannot be processed correctly. So I personally suggest writing the wrapped method manually.   Another scaffold method in Wind is the parallel tasks coordination. In this example, the steps of open database, retrieve records and recreated table should be invoked one by one, but it can be executed in parallel when copying data from database to table storage. In Wind there’s a scaffold function named Task.whenAll which can be used here. Task.whenAll accepts a list of tasks and creates a new task. It will be returned only when all tasks had been completed, or any errors occurred. For example in the code below I used the Task.whenAll to make all copy operation executed at the same time. 1: var copyRecordsInParallel = eval(Wind.compile("async", function (req, res) { 2: try { 3: // connect to the windows azure sql database 4: var conn = $await(sql.openAsync(connectionString)); 5: console.log("connection opened"); 6: // retrieve all records from database 7: var results = $await(sql.queryAsync(conn, "SELECT * FROM [Resource]")); 8: console.log("records selected. count = %d", results.rows.length); 9: if (results.rows.length > 0) { 10: // recreate the table 11: $await(azure.recreateTableAsync(tableName)); 12: console.log("table created"); 13: // insert records in table storage in parallal 14: var tasks = new Array(results.rows.length); 15: for (var i = 0; i < results.rows.length; i++) { 16: var entity = { 17: "PartitionKey": results.rows[i][1], 18: "RowKey": results.rows[i][0], 19: "Value": results.rows[i][2] 20: }; 21: tasks[i] = azure.insertEntityAsync(tableName, entity); 22: } 23: $await(Wind.Async.Task.whenAll(tasks)); 24: // send response 25: console.log("all done"); 26: res.send(200, "All done!"); 27: } 28: } 29: catch (ex) { 30: console.log(ex); 31: res.send(500, "Internal error."); 32: } 33: })); 34:  35: app.get("/was/copyRecordsInParallel", function (req, res) { 36: copyRecordsInParallel(req, res).start(); 37: });   Besides the task creation and coordination, Wind supports the cancellation solution so that we can send the cancellation signal to the tasks. It also includes exception solution which means any exceptions will be reported to the caller function.   Summary In this post I introduced a Node.js module named Wind, which created by my friend Jeff Zhao. As you can see, different from other async library and framework, adopted the idea from F# and C#, Wind utilizes runtime code generation technology to make it more easily to write async, callback-based functions in a sync-style way. By using Wind there will be almost no callback, and the code will be very easy to understand. Currently Wind is still under developed and improved. There might be some problems but the author, Jeff, should be very happy and enthusiastic to learn your problems, feedback, suggestion and comments. You can contact Jeff by - Email: [email protected] - Group: https://groups.google.com/d/forum/windjs - GitHub: https://github.com/JeffreyZhao/wind/issues   Source code can be download here.   Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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