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• Do You Think That SEO Really Effects Your Business?

  Before discussing about the importance of SEO we should know what it is actually. SEO or Search Engine Optimization is actually the procedure of improving the level or excellence of the traffic in a website from various search-engines by the means of natural or unpaid search results as contrasting to the search engine marketing or SEM which actually deals with the paid enclosure. The main importance of the SEO is that it generally makes the website appear higher or earlier in the list of the search results which attracts plenty of visitors from search engines. SEO generally targets different kinds of searches.

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• 2-components color model

  - by Cyan

  RGB is the natural color model for OpenGL. But a lot of other color models exist. For example, CMY(K) for printers, YUV for JPEG, the little cousins YCbCr and YCoCg, HSL & HSV from the 70's, and so on. All these models tend to share a common property : they are based on 3 components. Therefore my question is : Does it exist a 2-components color model ? I'm surprised to not find any. I was expecting something along the line of Hue+light could exist. I guess it cannot be as "complete" as a true 3-components color model, but a fine-enough approximation will be good for my usecase. The end objective is to store the 2 components into a single BC5 texture (GL_COMPRESSED_RED_GREEN_RGTC2 in OpenGL). The 3rd component requires a second fetch into a second texture, which hurts performance.

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• How do I get started with fog type effects in a first person game?

  - by Dream Lane

  Hey guys, I'm currently using JME3 to learn 3d game development in java, and I have run into a situation. I would like to add fog effects to my games, but I don't even know where to start to implement this. I know how to set the camera's far frustum to limit the render distance, but that just simply makes a sharp cutoff. I'd like the fog it up a bit to make it feel more natural. I'm looking for an answer that points me into the correct direction. I'm not looking for specific code snippets or even JME3's engine specifics. I just want to get an idea of how this stuff works in general. Thanks!

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• Ubuntu samba file and print server

  - by Gerd

  I am using an old Dell desktop PC as a samba file and print server for a Windows 7 network. The version of Unbuntu I am running is 12.04 which seems to big for the RAM and disk space I have available. Unbuntu 12.04 runs very very slow, the printing over the home network works at a quite acceptable speed. I have two problems: SLOW Ubuntu and I cannot update samba. The update manager tells me "update failed". So my two questions: Is there anything I can remove from the standard 12.04 installation to make Ubuntu run faster and should I uninstall and the reinstall samba to overcome the "update failed" problem? I hesitate, as printing and file serving works somehow and I don't want to loose that. I know I should give you more information to give me answers. But what would you need to know? I am not a natural Linux user. Windows 7 is still my home. Thanks in advance, Gerd

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• How to learn to translate real world problems to code?

  - by StudioWorks

  I'm kind of a beginner to Java and OOP and I didn't quite get the whole concept of seeing a real world problem and translating it to classes and code. For example, I was reading a book on UML and at the beginning the author takes the example of a tic tac toe game and says: "In this example, it's natural to see three classes: Board, Player and Position." Then, he creates the methods in each class and explains how they relate. What I can't understand is how he thought all this. So, where should I start to learn how to see a real world problem and then "translate" it into code?

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• Is it possible to procedurally place objects in a non-gridded game?

  - by nickbadal

  I'd like to implement procedural world generation, but I don't want it to look gridded or blocky, where everything is obviously placed on an integer grid. I know that you can do this in gridded worlds by inputting a square's x and y into a noise function, or similar, but is it possible to generate a more natural looking object placement using procedural methods? This is in the context of an adventure game, if it matters. Edit: I guess I should have been a bit more clear in my original question, but I'm mostly wondering about the actual placement of objects in game, e.g. trees, buildings.

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• How can I stop pixel seams appearing in adjacent mesh boundaries due to floating point imprecision?

  - by ufomorace

  Graphics cards are mathematically imprecise. So when some meshes are joined by their borders, the graphics card often makes mistakes and decides that some pixels at the seam represent neither object, and unwanted pixels appear. It's a natural behaviour on all graphics cards. How are such worries avoided in Pro Games? Batching? Shaders? Different tangent vectors? Merging? Overlaping seams? Dark backgrounds? Extra vertices at borders? Z precision? Camera distance tweaks? Screencap of a fix that ended up not working:

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• How do professional games avoid showing pixel seams in adjacent mesh boundaries due to decimal imprecision?

  - by ufomorace

  Graphics cards are mathematically imprecise. So when some meshes are joined by their borders, the graphics card often makes mistakes and decides that some pixels at the seam represent neither object, and unwanted pixels appear. It's a natural behaviour on all graphics cards. How are such worries avoided in Pro Games? Batching? Shaders? Different tangent vectors? Merging? Overlaping seams? Dark backgrounds? Extra vertices at borders? Z precision? Camera distance tweaks? Screencap of a fix that ended up not working:

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• Does having a higher paid technical job mean you do not get to code any more?

  - by c_maker

  I work at a large company where technical people fall roughly in one of these categories: A developer on a scrum team who develops for a single product and maybe works with other teams that are closely related to the product. An architect who is more of a consultant on multiple teams (5-6) and tries to recognize commonalities between team efforts that could be abstracted into libraries (architects do not write the library code, however). This architect also attends many meetings with management and attempts to set technical direction. In my company the architect role is where most technical people move into as the next step in their career. My questions are: Do most companies work such a way that their highest paid technical people are far removed from writing code? Is this a natural tendency for a developer's career? Can a developer have it all (code AND set direction?)

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• Resolution problems

  - by tampe125

  i'm having some troubles with screen resolution. First of all, i'm using a Lenovo Thinkpad E520, with BackTrack 5 R2 installed. As far as I know, BT is based on Ubuntu 3.2, so I hope this is the right place to ask for help. My natural resolution is 1366x768, but I'm stuck with 1024x768. This is my hardware: lspci | grep VGA 00:02.0 VGA compatible controller: Interl Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) How can I fix that? Is there a ready-to-use driver or I have to compile that from source? At least, is there a solution, at all? :(

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• How can you procedurally place objects in a non-gridded game?

  - by nickbadal

  This is a follow-up question to this question. I mistakenly worded the question, but got a good answer before I could correct myself, so I didn't want to delete it. Sorry! Now that I know that it is possible, I'd like to implement procedural world generation, but I don't want it to look gridded or blocky, where everything is obviously placed on an integer grid. I know that you can do this in gridded worlds by inputting a square's x and y into a noise function, or similar, but how can I generate a more natural looking object placement using procedural methods? This is in the context of an adventure game, if it matters.

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• Visual Studio goes international

  While code, the language of software, is universal, developers and end users speak in different tongues across the globe.  For software to meet the needs of all customers, it must interact in their languages, currencies, times and dates, and accommodate layouts that feel natural to the user.    In Developer Division, we put a great deal of thought and effort into building products for developers around the world.  For some languages, we do a complete translation of our products. ...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• Best way to develop a level from Top down image using 3dmax

  - by fire'fly

  I have to create a game level from a top down view of an area. I used a plane converted to an editable poly to do the job. I used edges to create the top view of roads, walkways and parks so that i can extrude/edit them later. My problem is the curves in the road look blocky I tried appying mesh smooth modifier on the final model but that interfered with material mapping. Again i tried it on the plane without the extrusions and still the modifier does not work(The roads loose their shape). I know one way to solve the problem is to add more vertices on the curve and transform their location to create a more natural curve but i have a lot of curves so before doing it manually i need to know if there is a tool that refines the curves. Also i need to know if there is a better or proper way of doing the task.

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• Need to add 30K new pages to a 10K page website - troubles ahead? (SEO)

  - by Jurga

  We have a situation with a website where we plan to add a huge amount of new pages. The domain is over 10 years old, approximately 10 thousand indexed pages, and the planned addition is approx. 30K new pages. Any idea how we should go about it? Must we schedule a gradual data release? Have you heard of any industry standards as to how many new pages per day / week / month should be added in order to appear natural and not get in trouble with Google? I.e. should we plan a bi-weekly addition of 5K?

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• What is your personal learning process? [closed]

  - by yadvent

  I just wanted to say hello and ask a few simple questions. I have recently dove into programming with c# and have been curious what everyone else's experiences have been with when learning and starting out. What are some things that you can say that really have made a difference in your understanding and usages of any particular language? I lurk several forums but for some reason have always just kept to myself, and I've realized today that I'm not fully utilizing my resources when it comes to interacting with the community. With that being said, I realize that everyone that is interested in programming inherently is a natural problem solver and would like also to ask you to share your process of learning. Are you the type to have a short term project to tackle a general set of problems you're likely to encounter? Or are you a type of programmer that practices by zeroing in on a specific few problems you would like to solve? Any reply will be greatly appreciated Thank you :)

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• Add keyboard languages to XP, Vista, and Windows 7

  - by Matthew Guay

  Do you regularly need to type in multiple languages in Windows?  Here we’ll show you the easy way to add and change input languages to your keyboard in XP, Vista, and Windows 7. Windows Vista and 7 come preinstalled with support for viewing a wide variety of languages, so adding an input language is fairly simply.  Adding an input language is slightly more difficult in XP, and requires installing additional files if you need an Asian or Complex script language.  First we show how to add an input language in Windows Vista and 7; it’s basically the same in both versions.  Then, we show how to add a language to XP, and also how to add Complex Script support.  Please note that this is only for adding an input language, which will allow you to type in the language you select.  This does not change your user interface language. Change keyboard language in Windows 7 and Vista It is fairly simple to add or change a keyboard language in Windows 7 or Vista.  In Windows 7, enter “keyboard language” in the Start menu search box, and select “Change keyboards or other input methods”. In Windows Vista, open Control Panel and enter “input language” in the search box and select “Change keyboards or other input methods”.  This also works in Windows 7. Now, click Change Keyboards to add another keyboard language or change your default one. Our default input language is US English, and our default keyboard is the US keyboard layout.  Click Add to insert another input language while still leaving your default input language installed. Here we selected the standard Thai keyboard language (Thai Kedmanee), but you can select any language you want.  Windows offers almost any language you can imagine, so just look for the language you want, select it, and click Ok. Alternately, if you want, you can click Preview to see your layout choice before accepting it.  This is only the default characters, not ones that will be activated with Shift or other keys (many Asian languages use many more characters than English, and require the use of Shift and other keys to access them all).  Once your finished previewing, click close and then press Ok on the previous dialog. Now you will see both of your keyboard languages in the Installed services box.  You can click Add to go back and get more, or move your selected language up or down (to change its priority), or simply click Apply to add the new language. Also, you can now change the default input language from the top menu.  This is the language that your keyboard will start with when you boot your computer.  So, if you mainly use English but also use another language, usually it is best to leave English as your default input language. Once you’ve pressed Apply or Ok, you will see a new icon beside your system tray with the initials of your default input language. If you click it, you can switch between input languages.  Alternately you can switch input languages by pressing Alt+Shift on your keyboard. Some complex languages, such as Chinese, may have extra buttons to change input modes to accommodate their large alphabet. If you would like to change the keyboard shortcut for changing languages, go back to the Input Languages dialog, and select the “Advanced Key Settings” tab.  Here you can change settings for Caps Lock and change or add key sequences to change between languages. Also, the On-Screen keyboard will display the correct keyboard language (here the keyboard is displaying Thai), which can be a helpful reference if your physical keyboard doesn’t have your preferred input language printed on it.  To open this, simply enter “On-Screen keyboard” in the start menu search, or click All Programs>Accessories>On-Screen keyboard. Change keyboard language in Windows XP The process for changing the keyboard language in Windows XP is slightly different.  Open Control Panel, and select “Date, Time, Language, and Regional Options”.   Select “Add other languages”. Now, click Details to add another language.  XP does not include support for Asian and complex languages by default, so if you need to add one of those languages we have details for that below. Click Add to add an input language. Select your desired language from the list, and choose your desired keyboard layout if your language offers multiple layouts.  Here we selected Canadian French with the default layout. Now you will see both of your keyboard languages in the Installed services box.  You can click Add to go back and add more, or move your selected language up or down (to change its priority), or simply click Apply to add the new language. Once you’ve pressed Apply or Ok, you will see a new icon beside your system tray with the initials of your default input language. If you click it, you can switch between input languages.  Alternately you can switch input languages by pressing Alt+Shift on your keyboard. If you would like to change the keyboard shortcut for changing languages, go back to the Input Languages dialog, and click the “Key Settings” button on the bottom of the dialog.  Here you can change settings for Caps Lock and change or add key sequences to change between languages. Add support to XP for Asian and Complex script languages Windows XP does not include support for Asian and Complex script languages by default, but you can easily add them to your computer.  This is useful if you wish to type in one of these languages, or simply want to read text written in these languages, since XP will not display these languages correctly if they are not installed.  If you wish to install Chinese, Japanese, and/or Korean, check the “Install files for East Asian languages” box.  Or, if you need to install a complex script language (including Arabic, Armenian, Georgian, Hebrew, the Indic languages, Thai, and Vietnamese), check the “Install files for complex script and right-to-left languages” box.   Choosing either of these options will open a prompt reminding you that this option will take up more disk space.  Support for complex languages will require around 10Mb of hard drive space, but East Asian language support may require 230 Mb or more free disk space.  Click Ok, and click apply to install your language files. You may have to insert your XP CD into your CD drive to install these files.  Insert the disk, and then click Ok. Windows will automatically copy the files, including fonts for these languages… …and then will ask you to reboot your computer to finalize the settings.  Click Yes, and then reopen the “Add other languages” dialog when your computer is rebooted, and add a language as before.     Now you can add Complex and/or Asian languages to XP, just as above.  Here is the XP taskbar language selector with Thai installed. Conclusion Unfortunately we haven’t found a way to add Asian and complex languages in XP without having an XP disc. If you know of a way, let us know in the comments. (No downloading the XP disc from torrent site answers please) Adding an input language is very important for bilingual individuals, and can also be useful if you simply need to occasionally view Asian or Complex languages in XP.  And by following the correct instructions for your version of Windows, it should be very easy to add, change, and remove input languages. Similar Articles Productive Geek Tips Show Keyboard Shortcut Access Keys in Windows VistaKeyboard Ninja: 21 Keyboard Shortcut ArticlesAnother Desktop Cube for Windows XP/VistaThe "Up" Keyboard Shortcut for Windows 7 or Vista ExplorerWhat is ctfmon.exe And Why Is It Running? TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 PCmover Professional Make your Joomla & Drupal Sites Mobile with OSMOBI Integrate Twitter and Delicious and Make Life Easier Design Your Web Pages Using the Golden Ratio Worldwide Growth of the Internet How to Find Your Mac Address Use My TextTools to Edit and Organize Text

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• How do I get preferences to work in Android?

  - by Dan T

  I've really been struggling through this. New to Java/Android. I'm writing my first app and this is the first thing that has taken me longer than a couple days of searching to figure out. Here's the setup: It's a BAC calculator / drink counter: A formula is used to calculate the BAC. Here's the forumla: Bac = ((StandardDrinks / 2) * (GenderConstant / Weight)) - (0.017 * Hours); So as you can see, being able to modify the gender and weight will produce more accurate and personalized results. So I have them as doubles: double GenderConstant = 7.5; //9 for female double Weight = 180; To change these variables I would like the person to be able to go into the settings and choose different values. I have these things set up, but not linked to the variables shown above because I cannot for the life of me figure out how. Here they are: I press the menu button and this pops up. Great. I'll click Settings. Now the preferences pops up. Here is my preferences.xml: <?xml version="1.0" encoding="utf-8"?> <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"> <PreferenceCategory android:title="Personal Settings"> <ListPreference android:title="Gender" android:summary="Verify or deny the presence of a Y chromosome." android:key="genderPref" android:defaultValue="male" android:entries="@array/genderArray" android:entryValues="@array/genderValues" /> <ListPreference android:title="Weight" android:summary="How much the planet pulls on you, in pounds." android:key="weightPref" android:defaultValue="180" android:entries="@array/weightArray" android:entryValues="@array/weightValues" /> </PreferenceCategory> <PreferenceCategory android:title="Drink Settings"> <ListPreference android:title="Beer Size" android:summary="The volume of your beer, in ounces." android:key="beerPref" android:defaultValue="12" android:entries="@array/beerArray" android:entryValues="@array/beerValues" /> <ListPreference android:title="Shot Size" android:summary="The volume of your shot, in ounces." android:key="shotPref" android:defaultValue="1.5" android:entries="@array/shotArray" android:entryValues="@array/shotValues" /> <ListPreference android:title="Wine Size" android:summary="The volume of your wine, in ounces." android:key="winePref" android:defaultValue="5" android:entries="@array/wineArray" android:entryValues="@array/wineValues" /> </PreferenceCategory> </PreferenceScreen> Onward to the weight ListPreference: And that shows up. The values are stored as string-arrays in res/values/arrays.xml. Here's a sample, of just the weight ones: <string-array name="weightArray"> <item>120 lbs</item> <item>150 lbs</item> <item>180 lbs</item> <item>210 lbs</item> <item>240 lbs</item> <item>270 lbs</item> </string-array> <string-array name="weightValues"> <item>120</item> <item>150</item> <item>180</item> <item>210</item> <item>240</item> <item>270</item> </string-array> This is basically as far as I've gotten. I can click a value, sure, but it doesn't change the formula because it's not linked with the doubles I created in DrinkingBuddy.java. All of the stuff displayed in the settings are just empty shells for now, including the spinner on the main layout (the default time is just set to 1 hour) I did create a Preferences.java and have tried implementing various combinations of code found in tutorials and resources around the web, but to no avail. Here it is anyway, filled with failed attempts to make beerPref (the settings option to change how many ounces in the beer) correlate with a variable in my main class: package com.dantoth.drinkingbuddy; import android.app.Activity; import android.content.SharedPreferences; import android.os.Bundle; import android.preference.Preference; import android.preference.PreferenceActivity; import android.preference.Preference.OnPreferenceClickListener; public class Preferences extends PreferenceActivity { public static final String PREF_BEER_SIZE = "PREF_BEER_SIZE"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.preferences); //Get the custom preference Preference beerPref = (Preference) findPreference("beerPref"); beerPref.setOnPreferenceClickListener(new OnPreferenceClickListener() { public boolean onPreferenceClick(Preference preference) { SharedPreferences customSharedPreference = getSharedPreferences("myCustomSharedPrefs", Activity.MODE_PRIVATE); SharedPreferences.Editor editor = customSharedPreference.edit(); editor.commit(); return true; }} );} } A full on tutorial and sample code would be AWESOME as I've yet to find any reliable guides out there.

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• BNF – how to read syntax?

  - by Piotr Rodak

  A few days ago I read post of Jen McCown (blog) about her idea of blogging about random articles from Books Online. I think this is a great idea, even if Jen says that it’s not exciting or sexy. I noticed that many of the questions that appear on forums and other media arise from pure fact that people asking questions didn’t bother to read and understand the manual – Books Online. Jen came up with a brilliant, concise acronym that describes very well the category of posts about Books Online – RTFM365. I take liberty of tagging this post with the same acronym. I often come across questions of type – ‘Hey, i am trying to create a table, but I am getting an error’. The error often says that the syntax is invalid. 1 CREATE TABLE dbo.Employees 2 (guid uniqueidentifier CONSTRAINT DEFAULT Guid_Default NEWSEQUENTIALID() ROWGUIDCOL, 3 Employee_Name varchar(60) 4 CONSTRAINT Guid_PK PRIMARY KEY (guid) ); 5 The answer is usually(1), ‘Ok, let me check it out.. Ah yes – you have to put name of the DEFAULT constraint before the type of constraint: 1 CREATE TABLE dbo.Employees 2 (guid uniqueidentifier CONSTRAINT Guid_Default DEFAULT NEWSEQUENTIALID() ROWGUIDCOL, 3 Employee_Name varchar(60) 4 CONSTRAINT Guid_PK PRIMARY KEY (guid) ); Why many people stumble on syntax errors? Is the syntax poorly documented? No, the issue is, that correct syntax of the CREATE TABLE statement is documented very well in Books Online and is.. intimidating. Many people can be taken aback by the rather complex block of code that describes all intricacies of the statement. However, I don’t know better way of defining syntax of the statement or command. The notation that is used to describe syntax in Books Online is a form of Backus-Naur notatiion, called BNF for short sometimes. This is a notation that was invented around 50 years ago, and some say that even earlier, around 400 BC – would you believe? Originally it was used to define syntax of, rather ancient now, ALGOL programming language (in 1950’s, not in ancient India). If you look closer at the definition of the BNF, it turns out that the principles of this syntax are pretty simple. Here are a few bullet points: italic_text is a placeholder for your identifier <italic_text_in_angle_brackets> is a definition which is described further. [everything in square brackets] is optional {everything in curly brackets} is obligatory everything | separated | by | operator is an alternative ::= “assigns” definition to an identifier Yes, it looks like these six simple points give you the key to understand even the most complicated syntax definitions in Books Online. Books Online contain an article about syntax conventions – have you ever read it? Let’s have a look at fragment of the CREATE TABLE statement: 1 CREATE TABLE 2 [ database_name . [ schema_name ] . | schema_name . ] table_name 3 ( { <column_definition> | <computed_column_definition> 4 | <column_set_definition> } 5 [ <table_constraint> ] [ ,...n ] ) 6 [ ON { partition_scheme_name ( partition_column_name ) | filegroup 7 | "default" } ] 8 [ { TEXTIMAGE_ON { filegroup | "default" } ] 9 [ FILESTREAM_ON { partition_scheme_name | filegroup 10 | "default" } ] 11 [ WITH ( <table_option> [ ,...n ] ) ] 12 [ ; ] Let’s look at line 2 of the above snippet: This line uses rules 3 and 5 from the list. So you know that you can create table which has specified one of the following. just name – table will be created in default user schema schema name and table name – table will be created in specified schema database name, schema name and table name – table will be created in specified database, in specified schema database name, .., table name – table will be created in specified database, in default schema of the user. Note that this single line of the notation describes each of the naming schemes in deterministic way. The ‘optionality’ of the schema_name element is nested within database_name.. section. You can use either database_name and optional schema name, or just schema name – this is specified by the pipe character ‘|’. The error that user gets with execution of the first script fragment in this post is as follows: Msg 156, Level 15, State 1, Line 2 Incorrect syntax near the keyword 'DEFAULT'. Ok, let’s have a look how to find out the correct syntax. Line number 3 of the BNF fragment above contains reference to <column_definition>. Since column_definition is in angle brackets, we know that this is a reference to notion described further in the code. And indeed, the very next fragment of BNF contains syntax of the column definition. 1 <column_definition> ::= 2 column_name <data_type> 3 [ FILESTREAM ] 4 [ COLLATE collation_name ] 5 [ NULL | NOT NULL ] 6 [ 7 [ CONSTRAINT constraint_name ] DEFAULT constant_expression ] 8 | [ IDENTITY [ ( seed ,increment ) ] [ NOT FOR REPLICATION ] 9 ] 10 [ ROWGUIDCOL ] [ <column_constraint> [ ...n ] ] 11 [ SPARSE ] Look at line 7 in the above fragment. It says, that the column can have a DEFAULT constraint which, if you want to name it, has to be prepended with [CONSTRAINT constraint_name] sequence. The name of the constraint is optional, but I strongly recommend you to make the effort of coming up with some meaningful name yourself. So the correct syntax of the CREATE TABLE statement from the beginning of the article is like this: 1 CREATE TABLE dbo.Employees 2 (guid uniqueidentifier CONSTRAINT Guid_Default DEFAULT NEWSEQUENTIALID() ROWGUIDCOL, 3 Employee_Name varchar(60) 4 CONSTRAINT Guid_PK PRIMARY KEY (guid) ); That is practically everything you should know about BNF. I encourage you to study the syntax definitions for various statements and commands in Books Online, you can find really interesting things hidden there. Technorati Tags: SQL Server,t-sql,BNF,syntax   (1) No, my answer usually is a question – ‘What error message? What does it say?’. You’d be surprised to know how many people think I can go through time and space and look at their screen at the moment they received the error.

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• SQL SERVER – Guest Post – Architecting Data Warehouse – Niraj Bhatt

  - by pinaldave

  Niraj Bhatt works as an Enterprise Architect for a Fortune 500 company and has an innate passion for building / studying software systems. He is a top rated speaker at various technical forums including Tech·Ed, MCT Summit, Developer Summit, and Virtual Tech Days, among others. Having run a successful startup for four years Niraj enjoys working on – IT innovations that can impact an enterprise bottom line, streamlining IT budgets through IT consolidation, architecture and integration of systems, performance tuning, and review of enterprise applications. He has received Microsoft MVP award for ASP.NET, Connected Systems and most recently on Windows Azure. When he is away from his laptop, you will find him taking deep dives in automobiles, pottery, rafting, photography, cooking and financial statements though not necessarily in that order. He is also a manager/speaker at BDOTNET, Asia’s largest .NET user group. Here is the guest post by Niraj Bhatt. As data in your applications grows it’s the database that usually becomes a bottleneck. It’s hard to scale a relational DB and the preferred approach for large scale applications is to create separate databases for writes and reads. These databases are referred as transactional database and reporting database. Though there are tools / techniques which can allow you to create snapshot of your transactional database for reporting purpose, sometimes they don’t quite fit the reporting requirements of an enterprise. These requirements typically are data analytics, effective schema (for an Information worker to self-service herself), historical data, better performance (flat data, no joins) etc. This is where a need for data warehouse or an OLAP system arises. A Key point to remember is a data warehouse is mostly a relational database. It’s built on top of same concepts like Tables, Rows, Columns, Primary keys, Foreign Keys, etc. Before we talk about how data warehouses are typically structured let’s understand key components that can create a data flow between OLTP systems and OLAP systems. There are 3 major areas to it: a) OLTP system should be capable of tracking its changes as all these changes should go back to data warehouse for historical recording. For e.g. if an OLTP transaction moves a customer from silver to gold category, OLTP system needs to ensure that this change is tracked and send to data warehouse for reporting purpose. A report in context could be how many customers divided by geographies moved from sliver to gold category. In data warehouse terminology this process is called Change Data Capture. There are quite a few systems that leverage database triggers to move these changes to corresponding tracking tables. There are also out of box features provided by some databases e.g. SQL Server 2008 offers Change Data Capture and Change Tracking for addressing such requirements. b) After we make the OLTP system capable of tracking its changes we need to provision a batch process that can run periodically and takes these changes from OLTP system and dump them into data warehouse. There are many tools out there that can help you fill this gap – SQL Server Integration Services happens to be one of them. c) So we have an OLTP system that knows how to track its changes, we have jobs that run periodically to move these changes to warehouse. The question though remains is how warehouse will record these changes? This structural change in data warehouse arena is often covered under something called Slowly Changing Dimension (SCD). While we will talk about dimensions in a while, SCD can be applied to pure relational tables too. SCD enables a database structure to capture historical data. This would create multiple records for a given entity in relational database and data warehouses prefer having their own primary key, often known as surrogate key. As I mentioned a data warehouse is just a relational database but industry often attributes a specific schema style to data warehouses. These styles are Star Schema or Snowflake Schema. The motivation behind these styles is to create a flat database structure (as opposed to normalized one), which is easy to understand / use, easy to query and easy to slice / dice. Star schema is a database structure made up of dimensions and facts. Facts are generally the numbers (sales, quantity, etc.) that you want to slice and dice. Fact tables have these numbers and have references (foreign keys) to set of tables that provide context around those facts. E.g. if you have recorded 10,000 USD as sales that number would go in a sales fact table and could have foreign keys attached to it that refers to the sales agent responsible for sale and to time table which contains the dates between which that sale was made. These agent and time tables are called dimensions which provide context to the numbers stored in fact tables. This schema structure of fact being at center surrounded by dimensions is called Star schema. A similar structure with difference of dimension tables being normalized is called a Snowflake schema. This relational structure of facts and dimensions serves as an input for another analysis structure called Cube. Though physically Cube is a special structure supported by commercial databases like SQL Server Analysis Services, logically it’s a multidimensional structure where dimensions define the sides of cube and facts define the content. Facts are often called as Measures inside a cube. Dimensions often tend to form a hierarchy. E.g. Product may be broken into categories and categories in turn to individual items. Category and Items are often referred as Levels and their constituents as Members with their overall structure called as Hierarchy. Measures are rolled up as per dimensional hierarchy. These rolled up measures are called Aggregates. Now this may seem like an overwhelming vocabulary to deal with but don’t worry it will sink in as you start working with Cubes and others. Let’s see few other terms that we would run into while talking about data warehouses. ODS or an Operational Data Store is a frequently misused term. There would be few users in your organization that want to report on most current data and can’t afford to miss a single transaction for their report. Then there is another set of users that typically don’t care how current the data is. Mostly senior level executives who are interesting in trending, mining, forecasting, strategizing, etc. don’t care for that one specific transaction. This is where an ODS can come in handy. ODS can use the same star schema and the OLAP cubes we saw earlier. The only difference is that the data inside an ODS would be short lived, i.e. for few months and ODS would sync with OLTP system every few minutes. Data warehouse can periodically sync with ODS either daily or weekly depending on business drivers. Data marts are another frequently talked about topic in data warehousing. They are subject-specific data warehouse. Data warehouses that try to span over an enterprise are normally too big to scope, build, manage, track, etc. Hence they are often scaled down to something called Data mart that supports a specific segment of business like sales, marketing, or support. Data marts too, are often designed using star schema model discussed earlier. Industry is divided when it comes to use of data marts. Some experts prefer having data marts along with a central data warehouse. Data warehouse here acts as information staging and distribution hub with spokes being data marts connected via data feeds serving summarized data. Others eliminate the need for a centralized data warehouse citing that most users want to report on detailed data. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Best Practices, Business Intelligence, Data Warehousing, Database, Pinal Dave, PostADay, Readers Contribution, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Hibernate mapping one-to-many problem

  - by Xorty

  Hello, I am not very experienced with Hibernate and I am trying to create one-to-many mapping. Here are relevant tables: And here are my mapping files: <hibernate-mapping package="com.xorty.mailclient.server.domain"> <class name="Attachment" table="Attachment"> <id name="id"> <column name="idAttachment"></column> </id> <property name="filename"> <column name="name"></column> </property> <property name="blob"> <column name="file"></column> <type name="blob"></type> </property> <property name="mailId"> <column name="mail_idmail"></column> </property> </class> </hibernate-mapping> <hibernate-mapping> <class name="com.xorty.mailclient.server.domain.Mail" table="mail"> <id name="id" type="integer" column="idmail"></id> <property name="content"> <column name="body"></column> </property> <property name="ownerAddress"> <column name="account_address"></column> </property> <property name="title"> <column name="head"></column> </property> <set name="receivers" table="mail_has_contact" cascade="all"> <key column="mail_idmail"></key> <many-to-many column="contact_address" class="com.xorty.mailclient.client.domain.Contact"></many-to-many> </set> <list name="attachments" cascade="save-update, delete" inverse="true"> <key column="mail_idmail" not-null="true"/> <index column="fk_Attachment_mail1"></index> <one-to-many class="com.xorty.mailclient.server.domain.Attachment"/> </list> </class> </hibernate-mapping> In plain english, one mail has more attachments. When I try to do CRUD on mail without attachments, everyting works just fine. When I add some attachment to mail, I cannot perform any CRUD operation. I end up with following trace: org.hibernate.exception.ConstraintViolationException: Could not execute JDBC batch update at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:96) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:275) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:268) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:184) at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321) at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51) at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1216) at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:383) at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:133) at domain.DatabaseTest.testPersistMailWithAttachment(DatabaseTest.java:355) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at junit.framework.TestCase.runTest(TestCase.java:168) at junit.framework.TestCase.runBare(TestCase.java:134) at junit.framework.TestResult$1.protect(TestResult.java:110) at junit.framework.TestResult.runProtected(TestResult.java:128) at junit.framework.TestResult.run(TestResult.java:113) at junit.framework.TestCase.run(TestCase.java:124) at junit.framework.TestSuite.runTest(TestSuite.java:232) at junit.framework.TestSuite.run(TestSuite.java:227) at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:83) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:49) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197) Caused by: java.sql.BatchUpdateException: Cannot add or update a child row: a foreign key constraint fails (`maildb`.`attachment`, CONSTRAINT `fk_Attachment_mail1` FOREIGN KEY (`mail_idmail`) REFERENCES `mail` (`idmail`) ON DELETE NO ACTION ON UPDATE NO ACTION) at com.mysql.jdbc.PreparedStatement.executeBatchSerially(PreparedStatement.java:1666) at com.mysql.jdbc.PreparedStatement.executeBatch(PreparedStatement.java:1082) at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:70) at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:268) ... 27 more Thank you

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• Getting Rails Application Running Under IronRuby Rack

  - by NotMyself

  Anyone else playing with ironruby? I have successfully got the IronRuby.Rails.Example project running on my local machine under IIS 5.1. I am now attempting to get my own demo rails site running in the same way. My web.config is slightly different from the example project. I am attempting to only use what was distributed with IronRuby 1.0 and what I have installed using gems. I am getting the following error which doesn't give me a lot to go on: D:/demo/config/boot.rb:66:in `exit': exit (SystemExit) After trying many different things, I think it is having a problem finding gems. I have attached my web config and ironrack.log. Does anyone have pointers on what I am doing wrong? Thanks! <?xml version="1.0"?> <configuration> <configSections> <!-- custom configuration section for DLR hosting --> <section name="microsoft.scripting" type="Microsoft.Scripting.Hosting.Configuration.Section, Microsoft.Scripting" requirePermission="false"/> </configSections> <system.webServer> <handlers> <!-- clear all other handlers first. Don't do this if you have other handlers you want to run --> <clear/> <!-- This hooks up the HttpHandler which will dispatch all requests to Rack --> <add name="IronRuby" path="*" verb="*" type="IronRuby.Rack.HttpHandlerFactory, IronRuby.Rack" resourceType="Unspecified" requireAccess="Read" preCondition="integratedMode"/> </handlers> </system.webServer> <system.web> <!-- make this true if you want to debug any of the DLR code, IronRuby.Rack, or your own managed code --> <compilation debug="true"/> <httpHandlers> <!-- clear all other handlers first. Don't do this if you have other handlers you want to run --> <clear/> <!-- This hooks up the HttpHandler which will dispatch all requests to Rack --> <add path="*" verb="*" type="IronRuby.Rack.HttpHandlerFactory, IronRuby.Rack" /> </httpHandlers> </system.web> <!-- DLR configuration. Set debugMode to "true" if you want to debug your dynamic language code with VS --> <microsoft.scripting debugMode="false"> <options> <!-- Library paths: make sure these paths are correct --> <!--<set option="LibraryPaths" value="..\..\..\Languages\Ruby\libs\; ..\..\..\..\External.LCA_RESTRICTED\Languages\Ruby\ruby-1.8.6p368\lib\ruby\site_ruby\1.8\; ..\..\..\..\External.LCA_RESTRICTED\Languages\Ruby\ruby-1.8.6p368\lib\ruby\1.8\"/>--> <set option="LibraryPaths" value="C:\IronRuby\lib\IronRuby;C:\IronRuby\lib\ruby\1.8;C:\IronRuby\lib\ruby\site_ruby;C:\IronRuby\lib\ruby\site_ruby\1.8"/> </options> </microsoft.scripting> <appSettings> <add key="AppRoot" value="."/> <add key="Log" value="ironrack.log"/> <!-- <add key="GemPath" value="..\..\..\..\External.LCA_RESTRICTED\Languages\Ruby\ruby-1.8.6p368\lib\ruby\gems\1.8"/> --> <add key="GemPath" value="C:\IronRuby\Lib\ironruby\gems\1.8\gems"/> <add key="RackEnv" value="production"/> </appSettings> </configuration> === Booting ironruby-rack at 4/15/2010 1:27:12 PM [DEBUG] >>> TOPLEVEL_BINDING = binding => Setting GEM_PATH: 'C:\\IronRuby\\Lib\\ironruby\\gems\\1.8\\gems' => Setting RACK_ENV: 'production' => Loading RubyGems [DEBUG] >>> require 'rubygems' => Loading Rack >=1.0.0 [DEBUG] >>> gem 'rack', '>=1.0.0';require 'rack' => Loaded rack-1.1 => Application root: 'D:\\demo' => Loading Rack application [DEBUG] >>> Rack::Builder.new { ( require "config/environment" ENV['RAILS_ENV'] = 'development' use Rails::Rack::LogTailer use Rails::Rack::Static run ActionController::Dispatcher.new ) }.to_app exit D:/demo/config/boot.rb:66:in `exit': exit (SystemExit) from D:/demo/config/boot.rb:66:in `load_rails_gem' from D:/demo/config/boot.rb:54:in `load_initializer' from D:/demo/config/boot.rb:38:in `run' from D:/demo/config/boot.rb:11:in `boot!' from D:/demo/config/boot.rb:110 from C:/IronRuby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require' from C:/IronRuby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require' from D:/demo/config/environment.rb:7 from C:/IronRuby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require' from C:/IronRuby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require' from (eval):1 from C:/IronRuby/lib/ironruby/gems/1.8/gems/rack-1.1.0/lib/rack/builder.rb:46:in `instance_eval' from C:/IronRuby/lib/ironruby/gems/1.8/gems/rack-1.1.0/lib/rack/builder.rb:46:in `initialize' from (eval):0 from D:\Dev\ironruby\ironruby-ironruby-20bc41b\Merlin\Main\Hosts\IronRuby.Rack\RubyEngine.cs:52:in `Execute' from D:\Dev\ironruby\ironruby-ironruby-20bc41b\Merlin\Main\Hosts\IronRuby.Rack\RubyEngine.cs:45:in `Execute' from D:\Dev\ironruby\ironruby-ironruby-20bc41b\Merlin\Main\Hosts\IronRuby.Rack\Application.cs:68:in `Rackup' from D:\Dev\ironruby\ironruby-ironruby-20bc41b\Merlin\Main\Hosts\IronRuby.Rack\Application.cs:32:in `.ctor' from D:\Dev\ironruby\ironruby-ironruby-20bc41b\Merlin\Main\Hosts\IronRuby.Rack\HttpHandlerFactory.cs:37:in `GetHandler' from System.Web:0:in `MapHttpHandler' from System.Web:0:in `System.Web.HttpApplication.IExecutionStep.Execute' from System.Web:0:in `ExecuteStep' from System.Web:0:in `ResumeSteps' from System.Web:0:in `System.Web.IHttpAsyncHandler.BeginProcessRequest' from System.Web:0:in `ProcessRequestInternal' from System.Web:0:in `ProcessRequestNoDemand' from System.Web:0:in `ProcessRequest'

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• while running mvn jetty:run showing the following error ..

  - by munna

  C:\source\myprojectmvn jetty:run [INFO] Scanning for projects... [INFO] ------------------------------------------------------------------------ [INFO] Building AppFuse Spring MVC Application [INFO] task-segment: [jetty:run] [INFO] ------------------------------------------------------------------------ [INFO] Preparing jetty:run [WARNING] POM for 'xfire:xfire-jsr181-api:pom:1.0-M1:compile' is invalid. Its dependencies (if any) will NOT be available to the current build. [INFO] [warpath:add-classes {execution: default}] [INFO] [aspectj:compile {execution: default}] [INFO] [native2ascii:native2ascii {execution: native2ascii-utf8}] [INFO] [native2ascii:native2ascii {execution: native2ascii-8859_1}] [INFO] [resources:resources {execution: default-resources}] [WARNING] File encoding has not been set, using platform encoding Cp1252, i.e. b uild is platform dependent! [WARNING] Using platform encoding (Cp1252 actually) to copy filtered resources, i.e. build is platform dependent! [INFO] Copying 12 resources [INFO] Copying 1 resource [INFO] Copying 26 resources [INFO] Copying 26 resources [INFO] [compiler:compile {execution: default-compile}] [INFO] Nothing to compile - all classes are up to date [INFO] [resources:testResources {execution: default-testResources}] [WARNING] File encoding has not been set, using platform encoding Cp1252, i.e. b uild is platform dependent! [WARNING] Using platform encoding (Cp1252 actually) to copy filtered resources, i.e. build is platform dependent! [INFO] Copying 4 resources [INFO] Copying 9 resources [INFO] Preparing hibernate3:hbm2ddl [WARNING] Removing: hbm2ddl from forked lifecycle, to prevent recursive invocati on. [INFO] [warpath:add-classes {execution: default}] [INFO] [aspectj:compile {execution: default}] [INFO] [native2ascii:native2ascii {execution: native2ascii-utf8}] [INFO] [native2ascii:native2ascii {execution: native2ascii-8859_1}] [INFO] [resources:resources {execution: default-resources}] [WARNING] File encoding has not been set, using platform encoding Cp1252, i.e. b uild is platform dependent! [WARNING] Using platform encoding (Cp1252 actually) to copy filtered resources, i.e. build is platform dependent! [INFO] Copying 12 resources [INFO] Copying 1 resource [INFO] Copying 26 resources [INFO] Copying 26 resources [INFO] Copying 26 resources [INFO] Copying 26 resources [INFO] [hibernate3:hbm2ddl {execution: default}] [INFO] Configuration XML file loaded: file:/C:/source/myproject/src/main/resourc es/hibernate.cfg.xml [INFO] Configuration XML file loaded: file:/C:/source/myproject/src/main/resourc es/hibernate.cfg.xml [INFO] Configuration Properties file loaded: C:\source\myproject\target\classes\ jdbc.properties alter table user_role drop foreign key FK143BF46A4FD90D75; alter table user_role drop foreign key FK143BF46AF503D155; drop table if exists app_user; drop table if exists role; drop table if exists user_role; create table app_user (id bigint not null auto_increment, account_expired bit no t null, account_locked bit not null, address varchar(150), city varchar(50) not null, country varchar(100), postal_code varchar(15) not null, province varchar(1 00), credentials_expired bit not null, email varchar(255) not null unique, accou nt_enabled bit, first_name varchar(50) not null, last_name varchar(50) not null, password varchar(255) not null, password_hint varchar(255), phone_number varcha r(255), username varchar(50) not null unique, version integer, website varchar(2 55), primary key (id)) ENGINE=InnoDB; create table role (id bigint not null auto_increment, description varchar(64), n ame varchar(20), primary key (id)) ENGINE=InnoDB; create table user_role (user_id bigint not null, role_id bigint not null, primar y key (user_id, role_id)) ENGINE=InnoDB; alter table user_role add index FK143BF46A4FD90D75 (role_id), add constraint FK1 43BF46A4FD90D75 foreign key (role_id) references role (id); alter table user_role add index FK143BF46AF503D155 (user_id), add constraint FK1 43BF46AF503D155 foreign key (user_id) references app_user (id); [INFO] [compiler:testCompile {execution: default-testCompile}] [INFO] Nothing to compile - all classes are up to date [INFO] [dbunit:operation {execution: test-compile}] [INFO] [jetty:run {execution: default-cli}] [INFO] Configuring Jetty for project: AppFuse Spring MVC Application [INFO] Webapp source directory = C:\source\myproject\src\main\webapp [INFO] web.xml file = C:\source\myproject\src\main\webapp\WEB-INF\web.xml [INFO] Classes = C:\source\myproject\target\classes [INFO] Adding extra scan target from pattern: C:\source\myproject\src\main\webap p\WEB-INF\applicationContext-validation.xml [INFO] Adding extra scan target from pattern: C:\source\myproject\src\main\webap p\WEB-INF\applicationContext.xml [INFO] Adding extra scan target from pattern: C:\source\myproject\src\main\webap p\WEB-INF\dispatcher-servlet.xml [INFO] Adding extra scan target from pattern: C:\source\myproject\src\main\webap p\WEB-INF\menu-config.xml [INFO] Adding extra scan target from pattern: C:\source\myproject\src\main\webap p\WEB-INF\urlrewrite.xml [INFO] Adding extra scan target from pattern: C:\source\myproject\src\main\webap p\WEB-INF\validation.xml [INFO] Adding extra scan target from pattern: C:\source\myproject\src\main\webap p\WEB-INF\validator-rules-custom.xml [INFO] Adding extra scan target from pattern: C:\source\myproject\src\main\webap p\WEB-INF\validator-rules.xml [INFO] Adding extra scan target from pattern: C:\source\myproject\src\main\webap p\WEB-INF\web.xml 2010-06-02 15:13:28.921::INFO: Logging to STDERR via org.mortbay.log.StdErrLog [INFO] Context path = / [INFO] Tmp directory = determined at runtime [INFO] Web defaults = org/mortbay/jetty/webapp/webdefault.xml [INFO] Web overrides = none [INFO] Webapp directory = C:\source\myproject\src\main\webapp [INFO] Starting jetty 6.1.9 ... 2010-06-02 15:13:28.983::INFO: jetty-6.1.9 2010-06-02 15:13:28.248::INFO: No Transaction manager found - if your webapp re quires one, please configure one. 2010-06-02 15:13:28.482:/:INFO: Initializing Spring root WebApplicationContext [myproject] ERROR [main] ContextLoader.initWebApplicationContext(215) | Context initialization failed org.springframework.beans.factory.BeanDefinitionStoreException: IOException pars ing XML document from ServletContext resource [/WEB-INF/xfire-servlet.xml]; nest ed exception is java.io.FileNotFoundException: Could not open ServletContext res ource [/WEB-INF/xfire-servlet.xml] at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBea nDefinitions(XmlBeanDefinitionReader.java:349) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBea nDefinitions(XmlBeanDefinitionReader.java:310) at org.springframework.beans.factory.support.AbstractBeanDefinitionReade r.loadBeanDefinitions(AbstractBeanDefinitionReader.java:143) at org.springframework.beans.factory.support.AbstractBeanDefinitionReade r.loadBeanDefinitions(AbstractBeanDefinitionReader.java:178) at org.springframework.beans.factory.support.AbstractBeanDefinitionReade r.loadBeanDefinitions(AbstractBeanDefinitionReader.java:149) at org.springframework.web.context.support.XmlWebApplicationContext.load BeanDefinitions(XmlWebApplicationContext.java:124) at org.springframework.web.context.support.XmlWebApplicationContext.load BeanDefinitions(XmlWebApplicationContext.java:92) at org.springframework.context.support.AbstractRefreshableApplicationCon text.refreshBeanFactory(AbstractRefreshableApplicationContext.java:123) at org.springframework.context.support.AbstractApplicationContext.obtain FreshBeanFactory(AbstractApplicationContext.java:423) at org.springframework.context.support.AbstractApplicationContext.refres h(AbstractApplicationContext.java:353) at org.springframework.web.context.ContextLoader.createWebApplicationCon text(ContextLoader.java:255) at org.springframework.web.context.ContextLoader.initWebApplicationConte xt(ContextLoader.java:199) at org.springframework.web.context.ContextLoaderListener.contextInitiali zed(ContextLoaderListener.java:45) at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler. java:540) at org.mortbay.jetty.servlet.Context.startContext(Context.java:135) at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.jav a:1220) at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java: 510) at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:448 ) at org.mortbay.jetty.plugin.Jetty6PluginWebAppContext.doStart(Jetty6Plug inWebAppContext.java:110) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java: 39) at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection .java:152) at org.mortbay.jetty.handler.ContextHandlerCollection.doStart(ContextHan dlerCollection.java:156) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java: 39) at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection .java:152) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java: 39) at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java: 130) at org.mortbay.jetty.Server.doStart(Server.java:222) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java: 39) at org.mortbay.jetty.plugin.Jetty6PluginServer.start(Jetty6PluginServer. java:132) at org.mortbay.jetty.plugin.AbstractJettyMojo.startJetty(AbstractJettyMo jo.java:357) at org.mortbay.jetty.plugin.AbstractJettyMojo.execute(AbstractJettyMojo. java:293) at org.mortbay.jetty.plugin.AbstractJettyRunMojo.execute(AbstractJettyRu nMojo.java:203) at org.mortbay.jetty.plugin.Jetty6RunMojo.execute(Jetty6RunMojo.java:184 ) at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPlugi nManager.java:490) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(Defa ultLifecycleExecutor.java:694) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeStandalone Goal(DefaultLifecycleExecutor.java:569) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(Defau ltLifecycleExecutor.java:539) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHan dleFailures(DefaultLifecycleExecutor.java:387) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegmen ts(DefaultLifecycleExecutor.java:348) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLi fecycleExecutor.java:180) at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:328) at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:138) at org.apache.maven.cli.MavenCli.main(MavenCli.java:362) at org.apache.maven.cli.compat.CompatibleMain.main(CompatibleMain.java:6 0) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl. java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces sorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315) at org.codehaus.classworlds.Launcher.launch(Launcher.java:255) at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430) at org.codehaus.classworlds.Launcher.main(Launcher.java:375) Caused by: java.io.FileNotFoundException: Could not open ServletContext resource [/WEB-INF/xfire-servlet.xml] at org.springframework.web.context.support.ServletContextResource.getInp utStream(ServletContextResource.java:116) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBea nDefinitions(XmlBeanDefinitionReader.java:336) ... 51 more 2010-06-02 15:13:29.919::WARN: Failed startup of context org.mortbay.jetty.plug in.Jetty6PluginWebAppContext@1ba4806{/,C:\source\myproject\src\main\webapp} org.springframework.beans.factory.BeanDefinitionStoreException: IOException pars ing XML document from ServletContext resource [/WEB-INF/xfire-servlet.xml]; nest ed exception is java.io.FileNotFoundException: Could not open ServletContext res ource [/WEB-INF/xfire-servlet.xml] at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBea nDefinitions(XmlBeanDefinitionReader.java:349) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBea nDefinitions(XmlBeanDefinitionReader.java:310) at org.springframework.beans.factory.support.AbstractBeanDefinitionReade r.loadBeanDefinitions(AbstractBeanDefinitionReader.java:143) at org.springframework.beans.factory.support.AbstractBeanDefinitionReade r.loadBeanDefinitions(AbstractBeanDefinitionReader.java:178) at org.springframework.beans.factory.support.AbstractBeanDefinitionReade r.loadBeanDefinitions(AbstractBeanDefinitionReader.java:149) at org.springframework.web.context.support.XmlWebApplicationContext.load BeanDefinitions(XmlWebApplicationContext.java:124) at org.springframework.web.context.support.XmlWebApplicationContext.load BeanDefinitions(XmlWebApplicationContext.java:92) at org.springframework.context.support.AbstractRefreshableApplicationCon text.refreshBeanFactory(AbstractRefreshableApplicationContext.java:123) at org.springframework.context.support.AbstractApplicationContext.obtain FreshBeanFactory(AbstractApplicationContext.java:423) at org.springframework.context.support.AbstractApplicationContext.refres h(AbstractApplicationContext.java:353) at org.springframework.web.context.ContextLoader.createWebApplicationCon text(ContextLoader.java:255) at org.springframework.web.context.ContextLoader.initWebApplicationConte xt(ContextLoader.java:199) at org.springframework.web.context.ContextLoaderListener.contextInitiali zed(ContextLoaderListener.java:45) at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler. java:540) at org.mortbay.jetty.servlet.Context.startContext(Context.java:135) at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.jav a:1220) at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java: 510) at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:448 ) at org.mortbay.jetty.plugin.Jetty6PluginWebAppContext.doStart(Jetty6Plug inWebAppContext.java:110) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java: 39) at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection .java:152) at org.mortbay.jetty.handler.ContextHandlerCollection.doStart(ContextHan dlerCollection.java:156) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java: 39) at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection .java:152) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java: 39) at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java: 130) at org.mortbay.jetty.Server.doStart(Server.java:222) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java: 39) at org.mortbay.jetty.plugin.Jetty6PluginServer.start(Jetty6PluginServer. java:132) at org.mortbay.jetty.plugin.AbstractJettyMojo.startJetty(AbstractJettyMo jo.java:357) at org.mortbay.jetty.plugin.AbstractJettyMojo.execute(AbstractJettyMojo. java:293) at org.mortbay.jetty.plugin.AbstractJettyRunMojo.execute(AbstractJettyRu nMojo.java:203) at org.mortbay.jetty.plugin.Jetty6RunMojo.execute(Jetty6RunMojo.java:184 ) at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPlugi nManager.java:490) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(Defa ultLifecycleExecutor.java:694) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeStandalone Goal(DefaultLifecycleExecutor.java:569) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(Defau ltLifecycleExecutor.java:539) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHan dleFailures(DefaultLifecycleExecutor.java:387) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegmen ts(DefaultLifecycleExecutor.java:348) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLi fecycleExecutor.java:180) at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:328) at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:138) at org.apache.maven.cli.MavenCli.main(MavenCli.java:362) at org.apache.maven.cli.compat.CompatibleMain.main(CompatibleMain.java:6 0) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl. java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces sorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315) at org.codehaus.classworlds.Launcher.launch(Launcher.java:255) at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430) at org.codehaus.classworlds.Launcher.main(Launcher.java:375) Caused by: java.io.FileNotFoundException: Could not open ServletContext resource [/WEB-INF/xfire-servlet.xml] at org.springframework.web.context.support.ServletContextResource.getInp utStream(ServletContextResource.java:116) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBea nDefinitions(XmlBeanDefinitionReader.java:336) ... 51 more 2010-06-02 15:13:29.152::WARN: Nested in org.springframework.beans.factory.Bean DefinitionStoreException: IOException parsing XML document from ServletContext r esource [/WEB-INF/xfire-servlet.xml]; nested exception is java.io.FileNotFoundEx ception: Could not open ServletContext resource [/WEB-INF/xfire-servlet.xml]: java.io.FileNotFoundException: Could not open ServletContext resource [/WEB-INF/ xfire-servlet.xml] at org.springframework.web.context.support.ServletContextResource.getInp utStream(ServletContextResource.java:116) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBea nDefinitions(XmlBeanDefinitionReader.java:336) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBea nDefinitions(XmlBeanDefinitionReader.java:310) at org.springframework.beans.factory.support.AbstractBeanDefinitionReade r.loadBeanDefinitions(AbstractBeanDefinitionReader.java:143) at org.springframework.beans.factory.support.AbstractBeanDefinitionReade r.loadBeanDefinitions(AbstractBeanDefinitionReader.java:178) at org.springframework.beans.factory.support.AbstractBeanDefinitionReade r.loadBeanDefinitions(AbstractBeanDefinitionReader.java:149) at org.springframework.web.context.support.XmlWebApplicationContext.load BeanDefinitions(XmlWebApplicationContext.java:124) at org.springframework.web.context.support.XmlWebApplicationContext.load BeanDefinitions(XmlWebApplicationContext.java:92) at org.springframework.context.support.AbstractRefreshableApplicationCon text.refreshBeanFactory(AbstractRefreshableApplicationContext.java:123) at org.springframework.context.support.AbstractApplicationContext.obtain FreshBeanFactory(AbstractApplicationContext.java:423) at org.springframework.context.support.AbstractApplicationContext.refres h(AbstractApplicationContext.java:353) at org.springframework.web.context.ContextLoader.createWebApplicationCon text(ContextLoader.java:255) at org.springframework.web.context.ContextLoader.initWebApplicationConte xt(ContextLoader.java:199) at org.springframework.web.context.ContextLoaderListener.contextInitiali zed(ContextLoaderListener.java:45) at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler. java:540) at org.mortbay.jetty.servlet.Context.startContext(Context.java:135) at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.jav a:1220) at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java: 510) at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:448 ) at org.mortbay.jetty.plugin.Jetty6PluginWebAppContext.doStart(Jetty6Plug inWebAppContext.java:110) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java: 39) at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection .java:152) at org.mortbay.jetty.handler.ContextHandlerCollection.doStart(ContextHan dlerCollection.java:156) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java: 39) at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection .java:152) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java: 39) at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java: 130) at org.mortbay.jetty.Server.doStart(Server.java:222) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java: 39) at org.mortbay.jetty.plugin.Jetty6PluginServer.start(Jetty6PluginServer. java:132) at org.mortbay.jetty.plugin.AbstractJettyMojo.startJetty(AbstractJettyMo jo.java:357) at org.mortbay.jetty.plugin.AbstractJettyMojo.execute(AbstractJettyMojo. java:293) at org.mortbay.jetty.plugin.AbstractJettyRunMojo.execute(AbstractJettyRu nMojo.java:203) at org.mortbay.jetty.plugin.Jetty6RunMojo.execute(Jetty6RunMojo.java:184 ) at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPlugi nManager.java:490) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(Defa ultLifecycleExecutor.java:694) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeStandalone Goal(DefaultLifecycleExecutor.java:569) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(Defau ltLifecycleExecutor.java:539) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHan dleFailures(DefaultLifecycleExecutor.java:387) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegmen ts(DefaultLifecycleExecutor.java:348) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLi fecycleExecutor.java:180) at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:328) at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:138) at org.apache.maven.cli.MavenCli.main(MavenCli.java:362) at org.apache.maven.cli.compat.CompatibleMain.main(CompatibleMain.java:6 0) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl. java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces sorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315) at org.codehaus.classworlds.Launcher.launch(Launcher.java:255) at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430) at org.codehaus.classworlds.Launcher.main(Launcher.java:375) 2010-06-02 15:13:29.417::INFO: Started [email protected]:8080 [INFO] Started Jetty Server [INFO] Starting scanner at interval of 3 seconds.

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• How to Easily Put a Windows PC into Kiosk Mode With Assigned Access

  - by Chris Hoffman

  Windows 8.1′s Assigned Access feature allows you to easily lock a Windows PC to a single application, such as a web browser. This feature makes it easy for anyone to configure Windows 8.1 devices as point-of-sale or other kiosk systems. In the past, setting up a Windows PC in kiosk mode involved much more work, requiring the use of third-party software, group policy, or Linux distributions designed around kiosk mode. Assigned Access is available on Windows 8.1 RT, Windows 8.1 Professional, and Windows 8.1 Enterprise. The standard edition of Windows 8.1 doesn’t support Assigned Access. Create a User Account for Assigned Access Rather than turn your entire computer into a locked-down kiosk system, Assigned Access allows you to create a separate user account that can only launch a single app — such as a web browser. To set this up, you must be logged into Windows as a user with administrator permissions. First, open the PC settings app — swipe in from the right or press Windows Key + C to open the charms bar, tap Settings, and tap Change PC settings. In the PC settings app, select Accounts and select Other accounts. Use the Add an account button to create a new Windows account. Select  the “Sign in without a Microsoft account” option and select Local account to create a local user account. You could also create a Microsoft account, but you may not want to do this if you just want a locked-down account with only browser access. If you need to install apps from the Windows Store to use in Assigned Access mode, you’ll have to set up a Microsoft account instead of a local account. A local account will still allow you access to the preinstalled apps, such as Internet Explorer. You may want to create a user account with a blank password. This would make it simple for anyone to access kiosk mode, even if the system becomes locked or needs to be rebooted. The account will be created as a standard user account with limited permissions. Leave it as a standard user account — don’t make it an administrator account. Set Up Assigned Access Once you’ve created an account, you’ll first need to sign into it. If you don’t, you’ll see a “This account has no apps” message when trying to enable Assigned Access. Go back to the welcome screen, log in to the new account you created, and allow Windows to go through the first-time account setup process. If you want to use a non-default app in kiosk mode, install it while logged in as that user account. Once you’re done, log out of the other account, log back in as your administrator account, and go back to the Other accounts screen. Click the Set up an account for assigned access option to continue. Select the user account you created and select the app you want to limit the account to. For a web-based kiosk, this can be a web browser such as the Modern version of Internet Explorer. Businesses can also create their own Modern apps and set them to run in kiosk mode in this way. Note that Microsoft’s documentation says “web browsers are not good choices for assigned access” because they require more permissions than average Modern (or “Windows Store”) apps. However, if you want to provide a kiosk for web-browsing, using Assigned Access is a much better option than using Guest Mode and offering up a full Windows desktop. When you’re done, restart your PC and log in as the Assigned Access account. Windows will automatically open the app you chose and won’t allow a user to leave that app. Standard Windows 8 features like the charms bar, app switcher, and Start screen won’t appear. Pressing the Windows key once will do nothing. To sign out of Assigned Access mode, press the Windows key five times — quickly — while signed in. You’ll be sent back to the standard login screen. The account will actually still be logged in and the app will remain running — this method just “locks” the screen and allows another user to log in. Automatically Log Into Assigned Access Whenever your Windows device boots, you can log into the Assigned Access account and turn it into a kiosk system. While this isn’t ideal for all kiosk systems, you may want the device to automatically launch the specific app when it boots without requiring any login process. To do so, you’ll just need to have Windows automatically log into the Assigned Access account when it boots. This option is hidden and not available in the standard Control Panel. You’ll need to use the hidden netplwiz Control Panel tool to set up automatic login on boot. If you didn’t create a password for the user account, leave the Password field empty while configuring this. Security Considerations If you’re using this feature to turn a Windows 8.1 system into a kiosk and leaving it open to the public, remember to consider security. Anyone could come up to the system, press the Windows key five times, and try to log into your standard administrator user account. Ensure the administrator user account has a strong password so people won’t be able to get past the kiosk system’s limitations and tamper with the system. Even Windows 8′s detractors have to admit that it’s an ideal system for a touch-screen kiosk device, running either a browser or another specific application. Assigned Access finally makes this easy to set up on Windows systems in the real world — no IT experience, third-party software, or Linux distributions necessary.     

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• Using Node.js as an accelerator for WCF REST services

  - by Elton Stoneman

  Node.js is a server-side JavaScript platform "for easily building fast, scalable network applications". It's built on Google's V8 JavaScript engine and uses an (almost) entirely async event-driven processing model, running in a single thread. If you're new to Node and your reaction is "why would I want to run JavaScript on the server side?", this is the headline answer: in 150 lines of JavaScript you can build a Node.js app which works as an accelerator for WCF REST services*. It can double your messages-per-second throughput, halve your CPU workload and use one-fifth of the memory footprint, compared to the WCF services direct.   Well, it can if: 1) your WCF services are first-class HTTP citizens, honouring client cache ETag headers in request and response; 2) your services do a reasonable amount of work to build a response; 3) your data is read more often than it's written. In one of my projects I have a set of REST services in WCF which deal with data that only gets updated weekly, but which can be read hundreds of times an hour. The services issue ETags and will return a 304 if the client sends a request with the current ETag, which means in the most common scenario the client uses its local cached copy. But when the weekly update happens, then all the client caches are invalidated and they all need the same new data. Then the service will get hundreds of requests with old ETags, and they go through the full service stack to build the same response for each, taking up threads and processing time. Part of that processing means going off to a database on a separate cloud, which introduces more latency and downtime potential.   We can use ASP.NET output caching with WCF to solve the repeated processing problem, but the server will still be thread-bound on incoming requests, and to get the current ETags reliably needs a database call per request. The accelerator solves that by running as a proxy - all client calls come into the proxy, and the proxy routes calls to the underlying REST service. We could use Node as a straight passthrough proxy and expect some benefit, as the server would be less thread-bound, but we would still have one WCF and one database call per proxy call. But add some smart caching logic to the proxy, and share ETags between Node and WCF (so the proxy doesn't even need to call the servcie to get the current ETag), and the underlying service will only be invoked when data has changed, and then only once - all subsequent client requests will be served from the proxy cache.   I've built this as a sample up on GitHub: NodeWcfAccelerator on sixeyed.codegallery. Here's how the architecture looks:     The code is very simple. The Node proxy runs on port 8010 and all client requests target the proxy. If the client request has an ETag header then the proxy looks up the ETag in the tag cache to see if it is current - the sample uses memcached to share ETags between .NET and Node. If the ETag from the client matches the current server tag, the proxy sends a 304 response with an empty body to the client, telling it to use its own cached version of the data. If the ETag from the client is stale, the proxy looks for a local cached version of the response, checking for a file named after the current ETag. If that file exists, its contents are returned to the client as the body in a 200 response, which includes the current ETag in the header. If the proxy does not have a local cached file for the service response, it calls the service, and writes the WCF response to the local cache file, and to the body of a 200 response for the client. So the WCF service is only troubled if both client and proxy have stale (or no) caches.   The only (vaguely) clever bit in the sample is using the ETag cache, so the proxy can serve cached requests without any communication with the underlying service, which it does completely generically, so the proxy has no notion of what it is serving or what the services it proxies are doing. The relative path from the URL is used as the lookup key, so there's no shared key-generation logic between .NET and Node, and when WCF stores a tag it also stores the "read" URL against the ETag so it can be used for a reverse lookup, e.g:   Key Value /WcfSampleService/PersonService.svc/rest/fetch/3 "28cd4796-76b8-451b-adfd-75cb50a50fa6" "28cd4796-76b8-451b-adfd-75cb50a50fa6" /WcfSampleService/PersonService.svc/rest/fetch/3    In Node we read the cache using the incoming URL path as the key and we know that "28cd4796-76b8-451b-adfd-75cb50a50fa6" is the current ETag; we look for a local cached response in /caches/28cd4796-76b8-451b-adfd-75cb50a50fa6.body (and the corresponding .header file which contains the original service response headers, so the proxy response is exactly the same as the underlying service). When the data is updated, we need to invalidate the ETag cache – which is why we need the reverse lookup in the cache. In the WCF update service, we don't need to know the URL of the related read service - we fetch the entity from the database, do a reverse lookup on the tag cache using the old ETag to get the read URL, update the new ETag against the URL, store the new reverse lookup and delete the old one.   Running Apache Bench against the two endpoints gives the headline performance comparison. Making 1000 requests with concurrency of 100, and not sending any ETag headers in the requests, with the Node proxy I get 102 requests handled per second, average response time of 975 milliseconds with 90% of responses served within 850 milliseconds; going direct to WCF with the same parameters, I get 53 requests handled per second, mean response time of 1853 milliseconds, with 90% of response served within 3260 milliseconds. Informally monitoring server usage during the tests, Node maxed at 20% CPU and 20Mb memory; IIS maxed at 60% CPU and 100Mb memory.   Note that the sample WCF service does a database read and sleeps for 250 milliseconds to simulate a moderate processing load, so this is *not* a baseline Node-vs-WCF comparison, but for similar scenarios where the  service call is expensive but applicable to numerous clients for a long timespan, the performance boost from the accelerator is considerable.     * - actually, the accelerator will work nicely for any HTTP request, where the URL (path + querystring) uniquely identifies a resource. In the sample, there is an assumption that the ETag is a GUID wrapped in double-quotes (e.g. "28cd4796-76b8-451b-adfd-75cb50a50fa6") – which is the default for WCF services. I use that assumption to name the cache files uniquely, but it is a trivial change to adapt to other ETag formats.

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• Master Details and collectionViewSource in separate views cannot make it work.

  - by devnet247

  Hi all, I really cannot seem to make/understand how it works with separate views It all works fine if a bundle all together in a single window. I have a list of Countries-Cities-etc... When you select a country it should load it's cities. Works So I bind 3 listboxes successfully using collection sources and no codebehind more or less (just code to set the datacontext and selectionChanged). you can download the project here http://cid-9db5ae91a2948485.skydrive.live.com/self.aspx/PublicFolder/2MasterDetails.zip <Window.Resources> <CollectionViewSource Source="{Binding}" x:Key="cvsCountryList"/> <CollectionViewSource Source="{Binding Source={StaticResource cvsCountryList},Path=Cities}" x:Key="cvsCityList"/> <CollectionViewSource Source="{Binding Source={StaticResource cvsCityList},Path=Hotels}" x:Key="cvsHotelList"/> </Window.Resources> <Grid> <Grid.ColumnDefinitions> <ColumnDefinition/> <ColumnDefinition/> <ColumnDefinition/> </Grid.ColumnDefinitions> <Grid.RowDefinitions> <RowDefinition Height="Auto"/> <RowDefinition/> </Grid.RowDefinitions> <TextBlock Grid.Column="0" Grid.Row="0" Text="Countries"/> <TextBlock Grid.Column="1" Grid.Row="0" Text="Cities"/> <TextBlock Grid.Column="2" Grid.Row="0" Text="Hotels"/> <ListBox Grid.Column="0" Grid.Row="1" Name="lstCountries" IsSynchronizedWithCurrentItem="True" ItemsSource="{Binding Source={StaticResource cvsCountryList}}" DisplayMemberPath="Name" SelectionChanged="OnSelectionChanged"/> <ListBox Grid.Column="1" Grid.Row="1" Name="lstCities" IsSynchronizedWithCurrentItem="True" ItemsSource="{Binding Source={StaticResource cvsCityList}}" DisplayMemberPath="Name" SelectionChanged="OnSelectionChanged"/> <ListBox Grid.Column="2" Grid.Row="1" Name="lstHotels" ItemsSource="{Binding Source={StaticResource cvsHotelList}}" DisplayMemberPath="Name" SelectionChanged="OnSelectionChanged"/> </Grid> Does not work I am trying to implement the same using a view for each eg(LeftSideMasterControl -RightSideDetailsControls) However I cannot seem to make them bind. Can you help? I would be very grateful so that I can understand how you communicate between userControls You can download the project here. http://cid-9db5ae91a2948485.skydrive.live.com/self.aspx/PublicFolder/2MasterDetails.zip I have as follows LeftSideMasterControl.xaml <Grid> <ListBox Name="lstCountries" SelectionChanged="OnSelectionChanged" DisplayMemberPath="Name" ItemsSource="{Binding Countries}"/> </Grid> RightViewDetailsControl.xaml MainView.xaml <CollectionViewSource Source="{Binding}" x:Key="cvsCountryList"/> <CollectionViewSource Source="{Binding Source={StaticResource cvsCountryList},Path=Cities}" x:Key="cvsCityList"/> </UserControl.Resources> <Grid> <Grid.ColumnDefinitions> <ColumnDefinition/> <ColumnDefinition Width="3*"/> </Grid.ColumnDefinitions> <Views:LeftViewMasterControl x:Name="leftSide" Margin="5" Content="{Binding Source=}"/> <GridSplitter Grid.Column="0" Grid.Row="0" Background="LightGray"/> <Views:RightViewDetailsControl Grid.Column="1" x:Name="RightSide" Margin="5"/> </Grid> ViewModels public class CountryListVM : ViewModelBase { public CountryListVM() { Countries = new ObservableCollection<CountryVM>(); } public ObservableCollection<CountryVM> Countries { get; set; } private RelayCommand _loadCountriesCommand; public ICommand LoadCountriesCommand { get { return _loadCountriesCommand ?? (_loadCountriesCommand = new RelayCommand(x => LoadCountries(), x => CanLoadCountries)); } } private static bool CanLoadCountries { get { return true; } } private void LoadCountries() { var countryList = Repository.GetCountries(); foreach (var country in countryList) { Countries.Add(new CountryVM { Name = country.Name }); } } } public class CountryVM : ViewModelBase { private string _name; public string Name { get { return _name; } set { _name = value; OnPropertyChanged("Name"); } } } public class CityListVM : ViewModelBase { private CountryVM _selectedCountry; public CityListVM(CountryVM country) { SelectedCountry = country; Cities = new ObservableCollection<CityVM>(); } public ObservableCollection<CityVM> Cities { get; set; } public CountryVM SelectedCountry { get { return _selectedCountry; } set { _selectedCountry = value; OnPropertyChanged("SelectedCountry"); } } private RelayCommand _loadCitiesCommand; public ICommand LoadCitiesCommand { get { return _loadCitiesCommand ?? (_loadCitiesCommand = new RelayCommand(x => LoadCities(), x => CanLoadCities)); } } private static bool CanLoadCities { get { return true; } } private void LoadCities() { var cities = Repository.GetCities(SelectedCountry.Name); foreach (var city in cities) { Cities.Add(new CityVM() { Name = city.Name }); } } } public class CityVM : ViewModelBase { private string _name; public string Name { get { return _name; } set { _name = value; OnPropertyChanged("Name"); } } } Models ========= public class Country { public Country() { Cities = new ObservableCollection<City>(); } public string Name { get; set; } public ObservableCollection<City> Cities { get; set; } } public class City { public City() { Hotels = new ObservableCollection<Hotel>(); } public string Name { get; set; } public ObservableCollection<Hotel> Hotels { get; set; } } public class Hotel { public string Name { get; set; } }

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