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• SQL SERVER – Weekly Series – Memory Lane – #049

  - by Pinal Dave

  Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 Two Connections Related Global Variables Explained – @@CONNECTIONS and @@MAX_CONNECTIONS @@CONNECTIONS Returns the number of attempted connections, either successful or unsuccessful since SQL Server was last started. @@MAX_CONNECTIONS Returns the maximum number of simultaneous user connections allowed on an instance of SQL Server. The number returned is not necessarily the number currently configured. Query Editor – Microsoft SQL Server Management Studio This post may be very simple for most of the users of SQL Server 2005. Earlier this year, I have received one question many times – Where is Query Analyzer in SQL Server 2005? I wrote small post about it and pointed many users to that post – SQL SERVER – 2005 Query Analyzer – Microsoft SQL SERVER Management Studio. Recently I have been receiving similar question. OUTPUT Clause Example and Explanation with INSERT, UPDATE, DELETE SQL Server 2005 has a new OUTPUT clause, which is quite useful. OUTPUT clause has access to insert and deleted tables (virtual tables) just like triggers. OUTPUT clause can be used to return values to client clause. OUTPUT clause can be used with INSERT, UPDATE, or DELETE to identify the actual rows affected by these statements. OUTPUT clause can generate a table variable, a permanent table, or temporary table. Even though, @@Identity will still work with SQL Server 2005, however I find the OUTPUT clause very easy and powerful to use. Let us understand the OUTPUT clause using an example. Find Name of The SQL Server Instance Based on database server stored procedures has to run different logic. We came up with two different solutions. 1) When database schema is very much changed, we wrote completely new stored procedure and deprecated older version once it was not needed. 2) When logic depended on Server Name we used global variable @@SERVERNAME. It was very convenient while writing migrating script which depended on the server name for the same database. Explanation of TRY…CATCH and ERROR Handling With RAISEERROR Function One of the developers at my company thought that we can not use the RAISEERROR function in new feature of SQL Server 2005 TRY… CATCH. When asked for an explanation he suggested SQL SERVER – 2005 Explanation of TRY… CATCH and ERROR Handling article as excuse suggesting that I did not give example of RAISEERROR with TRY…CATCH. We all thought it was funny. Just to keep records straight, TRY… CATCH can sure use RAISEERROR function. Different Types of Cache Objects Serveral kinds of objects can be stored in the procedure cache: Compiled Plans: When the query optimizer finishes compiling a query plan, the principal output is compiled plan. Execution contexts: While executing a compiled plan, SQL Server has to keep track of information about the state of execution. Cursors: Cursors track the execution state of server-side cursors, including the cursor’s current location within a resultset. Algebrizer trees: The Algebrizer’s job is to produce an algebrizer tree, which represents the logic structure of a query. Open SSMS From Command Prompt – sqlwb.exe Example This article is written by request and suggestion of Sr. Web Developer at my organization. Due to the nature of this article most of the content is referred from Book On-Line. sqlwbcommand prompt utility which opens SQL Server Management Studio. Squib command does not run queries from the command prompt. sqlcmd utility runs queries from command prompt, read for more information. 2008 Puzzle – Solution – Computed Columns Datatype Explanation Just a day before I wrote article SQL SERVER – Puzzle – Computed Columns Datatype Explanation which was inspired by SQL Server MVP Jacob Sebastian. I suggest that before continuing this article read the original puzzle question SQL SERVER – Puzzle – Computed Columns Datatype Explanation.The question was if the computed column was of datatype TINYINT how to create a Computed Column of datatype INT? 2008 – Find If Index is Being Used in Database It is very often I get a query that how to find if any index is being used in the database or not. If any database has many indexes and not all indexes are used it can adversely affect performance. If the number of indices are higher it reduces the INSERT / UPDATE / DELETE operation but increase the SELECT operation. It is recommended to drop any unused indexes from table to improve the performance. 2009 Interesting Observation – Execution Plan and Results of Aggregate Concatenation Queries If you want to see what’s going on here, I think you need to shift your point of view from an implementation-centric view to an ANSI point of view. ANSI does not guarantee processing the order. Figure 2 is interesting, but it will be potentially misleading if you don’t understand the ANSI rule-set SQL Server operates under in most cases. Implementation thinking can certainly be useful at times when you really need that multi-million row query to finish before the backup fire off, but in this case, it’s counterproductive to understanding what is going on. SQL Server Management Studio and Client Statistics Client Statistics are very important. Many a times, people relate queries execution plan to query cost. This is not a good comparison. Both parameters are different, and they are not always related. It is possible that the query cost of any statement is less, but the amount of the data returned is considerably larger, which is causing any query to run slow. How do we know if any query is retrieving a large amount data or very little data? 2010 I encourage all of you to go through complete series and write your own on the subject. If you write an article and send it to me, I will publish it on this blog with due credit to you. If you write on your own blog, I will update this blog post pointing to your blog post. SQL SERVER – ORDER BY Does Not Work – Limitation of the View 1 SQL SERVER – Adding Column is Expensive by Joining Table Outside View – Limitation of the View 2 SQL SERVER – Index Created on View not Used Often – Limitation of the View 3 SQL SERVER – SELECT * and Adding Column Issue in View – Limitation of the View 4 SQL SERVER – COUNT(*) Not Allowed but COUNT_BIG(*) Allowed – Limitation of the View 5 SQL SERVER – UNION Not Allowed but OR Allowed in Index View – Limitation of the View 6 SQL SERVER – Cross Database Queries Not Allowed in Indexed View – Limitation of the View 7 SQL SERVER – Outer Join Not Allowed in Indexed Views – Limitation of the View 8 SQL SERVER – SELF JOIN Not Allowed in Indexed View – Limitation of the View 9 SQL SERVER – Keywords View Definition Must Not Contain for Indexed View – Limitation of the View 10 SQL SERVER – View Over the View Not Possible with Index View – Limitations of the View 11 SQL SERVER – Get Query Running in Session I was recently looking for syntax where I needed a query running in any particular session. I always remembered the syntax and ha d actually written it down before, but somehow it was not coming to mind quickly this time. I searched online and I ended up on my own article written last year SQL SERVER – Get Last Running Query Based on SPID. I felt that I am getting old because I forgot this really simple syntax. Find Total Number of Transaction on Interval In one of my recent Performance Tuning assignments I was asked how do someone know how many transactions are happening on a server during certain interval. I had a handy script for the same. Following script displays transactions happened on the server at the interval of one minute. You can change the WAITFOR DELAY to any other interval and it should work. 2011 Here are two DMV’s which are newly introduced in SQL Server 2012 and provides vital information about SQL Server. DMV – sys.dm_os_volume_stats – Information about operating system volume DMV – sys.dm_os_windows_info – Information about Operating System SQL Backup and FTP – A Quick and Handy Tool I have used this tool extensively since 2009 at numerous occasion and found it to be very impressive. What separates it from the crowd the most – it is it’s apparent simplicity and speed. When I install SQLBackupAndFTP and configure backups – all in 1 or 2 minutes, my clients are always impressed. Quick Note about JOIN – Common Questions and Simple Answers In this blog post we are going to talk about join and lots of things related to the JOIN. I recently started office hours to answer questions and issues of the community. I receive so many questions that are related to JOIN. I will share a few of the same over here. Most of them are basic, but note that the basics are of great importance. 2012 Importance of User Without Login Question: “In recent version of SQL Server we can create user without login. What is the use of it?” Great question indeed. Let me first attempt to answer this question but after reading my answer I need your help. I want you to help him as well with adding more value to it. Preserve Leading Zero While Coping to Excel from SSMS Earlier I wrote two articles about how to efficiently copy data from SSMS to Excel. Since I wrote that post there are plenty of interest generated on this subject. There are a few questions I keep on getting over this subject. One of the question is how to get the leading zero preserved while copying the data from SSMS to Excel. Well it is almost the same way as my earlier post SQL SERVER – Excel Losing Decimal Values When Value Pasted from SSMS ResultSet. The key here is in EXCEL and not in SQL Server. Solution – 2 T-SQL Puzzles – Display Star and Shortest Code to Display 1 Earlier on this blog we had asked two puzzles. The response from all of you is nothing but Amazing. I have received 350+ responses. Many are valid and many were indeed something I had not thought about it. I strongly suggest you read all the puzzles and their answers here - trust me if you start reading the comments you will not stop till you read every single comment. Seriously trust me on it. Personally I have learned a lot from it. Identify Most Resource Intensive Queries – SQL in Sixty Seconds #028 – Video http://www.youtube.com/watch?v=TvlYy-TGaaA Importance of User Without Login – T-SQL Demo Script Earlier I wrote a blog post about SQL SERVER – Importance of User Without Login and my friend and SQL Expert Vinod Kumar has written excellent follow up blog post about Contained Databases inside SQL Server 2012. Now lots of people asked me if I can also explain the same concept again so here is the small demonstration for it. Let me show you how login without user can help. Before we continue on this subject I strongly recommend that you read my earlier blog post here. In following demo I am going to demonstrate following situation. Login using the System Admin account Create a user without login Checking Access Impersonate the user without login Checking Access Revert Impersonation Give Permission to user without login Impersonate the user without login Checking Access Revert Impersonation Clean up Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• How to properly deny Railo directory access through Apache

  - by Sn3akyP3t3

  I've been battle tested on this and failed to achieve my goal which is to deny all access to all directories except the Public directory and only allow access to all all other directories with specific IP addresses. To get Railo+Apache+Tomcat installed I pretty much followed this script: https://github.com/talltroym/Railo-Ubuntu-Installer-Script then verified settings with this tutorial: http://blog.nictunney.com/2012/03/railo-tomcat-and-apache-on-amazon-ec2.html From the installation script these mods are enabled: sudo a2enmod ssl sudo a2enmod proxy sudo a2enmod proxy_http sudo a2enmod rewrite sudo a2ensite default-ssl Outside of the script I copied the sites-available to sites-enabled then reloaded Apache. I have a directory created for Railo cmfl located at /var/www/Railo/ Navigating the browser to http ://Server_IP_Address/Railo forces ssl and relocates to https ://Server_IP_Address/Railo which shows off index.cfm. Not providing index.cfm and omitting https indicates that the DirectoryIndex directive and RewriteCond of Apache appears to be working for the sites-enabled VirtualHost. The problem I'm encountering is that I cannot seem to deny access to all directories except Public. My directory structure is rather simple and looks like this: Railo error Public NotPublic Sandbox These are my sites-enabled configurations: <VirtualHost *:80> ServerAdmin webmaster@localhost DocumentRoot /var/www #Default Deny All to prevent walking backwards in file system Alias /Railo/ "/var/www/Railo/" <Directory ~ ".*/Railo/(?!Public).*"> Order Deny,Allow Deny from All </Directory> ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/ <Directory "/usr/lib/cgi-bin"> AllowOverride None Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch Order allow,deny Allow from all </Directory> ErrorLog ${APACHE_LOG_DIR}/error.log # Possible values include: debug, info, notice, warn, error, crit, # alert, emerg. LogLevel warn CustomLog ${APACHE_LOG_DIR}/access.log combined Alias /doc/ "/usr/share/doc/" <Directory "/usr/share/doc/"> Options Indexes MultiViews FollowSymLinks AllowOverride None Order deny,allow Deny from all Allow from 127.0.0.0/255.0.0.0 ::1/128 </Directory> DirectoryIndex index.cfm index.cfml default.cfm default.cfml index.htm index.html index.cfc RewriteEngine on RewriteCond %{SERVER_PORT} !^443$ RewriteRule ^.*$ https://%{SERVER_NAME}%{REQUEST_URI} [L,R] </VirtualHost> and <IfModule mod_ssl.c> <VirtualHost _default_:443> ServerAdmin webmaster@localhost DocumentRoot /var/www Alias /Railo/ "/var/www/Railo/" <Directory ~ "/var/www/Railo/(?!Public).*"> Order Deny,Allow Deny from All </Directory> ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/ <Directory "/usr/lib/cgi-bin"> AllowOverride None Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch Order allow,deny Allow from all </Directory> ErrorLog ${APACHE_LOG_DIR}/error.log # Possible values include: debug, info, notice, warn, error, crit, # alert, emerg. LogLevel warn CustomLog ${APACHE_LOG_DIR}/ssl_access.log combined Alias /doc/ "/usr/share/doc/" <Directory "/usr/share/doc/"> Options Indexes MultiViews FollowSymLinks AllowOverride None Order deny,allow Deny from all Allow from 127.0.0.0/255.0.0.0 ::1/128 </Directory> # SSL Engine Switch: # Enable/Disable SSL for this virtual host. SSLEngine on # A self-signed (snakeoil) certificate can be created by installing # the ssl-cert package. See # /usr/share/doc/apache2.2-common/README.Debian.gz for more info. # If both key and certificate are stored in the same file, only the # SSLCertificateFile directive is needed. SSLCertificateFile /etc/ssl/certs/ssl-cert-snakeoil.pem SSLCertificateKeyFile /etc/ssl/private/ssl-cert-snakeoil.key # Server Certificate Chain: # Point SSLCertificateChainFile at a file containing the # concatenation of PEM encoded CA certificates which form the # certificate chain for the server certificate. Alternatively # the referenced file can be the same as SSLCertificateFile # when the CA certificates are directly appended to the server # certificate for convinience. #SSLCertificateChainFile /etc/apache2/ssl.crt/server-ca.crt # Certificate Authority (CA): # Set the CA certificate verification path where to find CA # certificates for client authentication or alternatively one # huge file containing all of them (file must be PEM encoded) # Note: Inside SSLCACertificatePath you need hash symlinks # to point to the certificate files. Use the provided # Makefile to update the hash symlinks after changes. #SSLCACertificatePath /etc/ssl/certs/ #SSLCACertificateFile /etc/apache2/ssl.crt/ca-bundle.crt # Certificate Revocation Lists (CRL): # Set the CA revocation path where to find CA CRLs for client # authentication or alternatively one huge file containing all # of them (file must be PEM encoded) # Note: Inside SSLCARevocationPath you need hash symlinks # to point to the certificate files. Use the provided # Makefile to update the hash symlinks after changes. #SSLCARevocationPath /etc/apache2/ssl.crl/ #SSLCARevocationFile /etc/apache2/ssl.crl/ca-bundle.crl # Client Authentication (Type): # Client certificate verification type and depth. Types are # none, optional, require and optional_no_ca. Depth is a # number which specifies how deeply to verify the certificate # issuer chain before deciding the certificate is not valid. #SSLVerifyClient require #SSLVerifyDepth 10 # Access Control: # With SSLRequire you can do per-directory access control based # on arbitrary complex boolean expressions containing server # variable checks and other lookup directives. The syntax is a # mixture between C and Perl. See the mod_ssl documentation # for more details. #<Location /> #SSLRequire ( %{SSL_CIPHER} !~ m/^(EXP|NULL)/ \ # and %{SSL_CLIENT_S_DN_O} eq "Snake Oil, Ltd." \ # and %{SSL_CLIENT_S_DN_OU} in {"Staff", "CA", "Dev"} \ # and %{TIME_WDAY} >= 1 and %{TIME_WDAY} <= 5 \ # and %{TIME_HOUR} >= 8 and %{TIME_HOUR} <= 20 ) \ # or %{REMOTE_ADDR} =~ m/^192\.76\.162\.[0-9]+$/ #</Location> # SSL Engine Options: # Set various options for the SSL engine. # o FakeBasicAuth: # Translate the client X.509 into a Basic Authorisation. This means that # the standard Auth/DBMAuth methods can be used for access control. The # user name is the `one line' version of the client's X.509 certificate. # Note that no password is obtained from the user. Every entry in the user # file needs this password: `xxj31ZMTZzkVA'. # o ExportCertData: # This exports two additional environment variables: SSL_CLIENT_CERT and # SSL_SERVER_CERT. These contain the PEM-encoded certificates of the # server (always existing) and the client (only existing when client # authentication is used). This can be used to import the certificates # into CGI scripts. # o StdEnvVars: # This exports the standard SSL/TLS related `SSL_*' environment variables. # Per default this exportation is switched off for performance reasons, # because the extraction step is an expensive operation and is usually # useless for serving static content. So one usually enables the # exportation for CGI and SSI requests only. # o StrictRequire: # This denies access when "SSLRequireSSL" or "SSLRequire" applied even # under a "Satisfy any" situation, i.e. when it applies access is denied # and no other module can change it. # o OptRenegotiate: # This enables optimized SSL connection renegotiation handling when SSL # directives are used in per-directory context. #SSLOptions +FakeBasicAuth +ExportCertData +StrictRequire <FilesMatch "\.(cgi|shtml|phtml|php)$"> SSLOptions +StdEnvVars </FilesMatch> <Directory /usr/lib/cgi-bin> SSLOptions +StdEnvVars </Directory> # SSL Protocol Adjustments: # The safe and default but still SSL/TLS standard compliant shutdown # approach is that mod_ssl sends the close notify alert but doesn't wait for # the close notify alert from client. When you need a different shutdown # approach you can use one of the following variables: # o ssl-unclean-shutdown: # This forces an unclean shutdown when the connection is closed, i.e. no # SSL close notify alert is send or allowed to received. This violates # the SSL/TLS standard but is needed for some brain-dead browsers. Use # this when you receive I/O errors because of the standard approach where # mod_ssl sends the close notify alert. # o ssl-accurate-shutdown: # This forces an accurate shutdown when the connection is closed, i.e. a # SSL close notify alert is send and mod_ssl waits for the close notify # alert of the client. This is 100% SSL/TLS standard compliant, but in # practice often causes hanging connections with brain-dead browsers. Use # this only for browsers where you know that their SSL implementation # works correctly. # Notice: Most problems of broken clients are also related to the HTTP # keep-alive facility, so you usually additionally want to disable # keep-alive for those clients, too. Use variable "nokeepalive" for this. # Similarly, one has to force some clients to use HTTP/1.0 to workaround # their broken HTTP/1.1 implementation. Use variables "downgrade-1.0" and # "force-response-1.0" for this. BrowserMatch "MSIE [2-6]" \ nokeepalive ssl-unclean-shutdown \ downgrade-1.0 force-response-1.0 # MSIE 7 and newer should be able to use keepalive BrowserMatch "MSIE [17-9]" ssl-unclean-shutdown DirectoryIndex index.cfm index.cfml default.cfm default.cfml index.htm index.html #Proxy .cfm and cfc requests to Railo ProxyPassMatch ^/(.+.cf[cm])(/.*)?$ http://127.0.0.1:8888/$1 ProxyPassReverse / http://127.0.0.1:8888/ #Deny access to admin except for local clients <Location /railo-context/admin/> Order deny,allow Deny from all # Allow from <Omitted> # Allow from <Omitted> Allow from 127.0.0.1 </Location> </VirtualHost> </IfModule> The apache2.conf includes the following: # Include the virtual host configurations: Include sites-enabled/ <IfModule !mod_jk.c> LoadModule jk_module /usr/lib/apache2/modules/mod_jk.so </IfModule> <IfModule mod_jk.c> JkMount /*.cfm ajp13 JkMount /*.cfc ajp13 JkMount /*.do ajp13 JkMount /*.jsp ajp13 JkMount /*.cfchart ajp13 JkMount /*.cfm/* ajp13 JkMount /*.cfml/* ajp13 # Flex Gateway Mappings # JkMount /flex2gateway/* ajp13 # JkMount /flashservices/gateway/* ajp13 # JkMount /messagebroker/* ajp13 JkMountCopy all JkLogFile /var/log/apache2/mod_jk.log </IfModule> I believe I understand most of this except the jk_module inclusion which I've noticed has an error that shows up in the logs that I can't sort out: [warn] No JkShmFile defined in httpd.conf. Using default /etc/apache2/logs/jk-runtime-status I've checked my Regular expression against the paths of the directories with RegexBuddy just to be sure that I wasn't correct. The problem doesn't appear to be Regex related although I may have something incorrect in the Directory directive. The Location directive seems to be working correctly for blocking out Railo admin site access.

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• CodePlex Daily Summary for Monday, January 10, 2011

  CodePlex Daily Summary for Monday, January 10, 2011Popular ReleasesSense/Net Enterprise Portal & ECMS: SenseNet 6.0.1 Community Edition for .NET 4: SenseNet 6.0.1 Community Edition for .NET 4 with SQL CE 4.0 This half year we have been working quite fiercely to bring you the long-awaited release of Sense/Net 6.0. Download this Community Edition for .NET 4 Platform to see what we have been up to. These months we have worked on getting the WebCMS capabilities of Sense/Net 6.0 up to par. New features include: New, powerful page and portlet editing experience. HTML and CSS cleanup, new, powerful site skinning system. Upgraded, light...Agile Personal Body Of Knowledge: ????－????，???? v0.2.pdf: ????【????－????，????.pdf】???，?????????????????????????????，???????????，???????。 ??????????，??????????，????????，?????????！ ????sina??：http://q.t.sina.com.cn/135484VSSpeedster - Parallel Builds for VS: VSSpeedster 1.1: - Parallel Builds with MSBuild integrated in Visual StudioBernie's Trackviewer: Bernie's Trackviewer Version 1.2: Redesigned user interface of main form Also displays waypoints which are not part of a track Can convert a route int a track Maximum age of cached maps can be setPeople's Note: People's Note 0.21: Replaced note viewer buttons with a menu bar to improve scrolling performance. Fixed database relocation on low-resolution devices; thanks to compaNet for reporting. Improved signin error messages. To install: copy the appropriate CAB file onto your WM device and run it.mytrip.mvc (CMS & e-Commerce): mytrip.mvc 1.0.51.0 beta2: WEB.mytrip.mvc 1.0.51.0 Web for install hosting System Requirements: NET 4.0, MSSQL 2008 or MySql (auto creation table to database) if .\SQLEXPRESS auto creation database (App_Data folder) SRC.mytrip.mvc 1.0.51.0 System Requirements: Visual Studio 2010 or Web Deweloper 2010 MSSQL 2008 or MySql (auto creation table to database) if .\SQLEXPRESS auto creation database (App_Data folder) Connector/Net 6.3.5, MVC3 RC WARNING For run and debug SRC.mytrip.mvc 1.0.51.0 download and install MVC3 RC...EnhSim: EnhSim 2.3.0: 2.3.0This release supports WoW patch 4.03a at level 85 To use this release, you must have the Microsoft Visual C++ 2010 Redistributable Package installed. This can be downloaded from http://www.microsoft.com/downloads/en/details.aspx?FamilyID=A7B7A05E-6DE6-4D3A-A423-37BF0912DB84 To use the GUI you must have the .NET 4.0 Framework installed. This can be downloaded from http://www.microsoft.com/downloads/en/details.aspx?FamilyID=9cfb2d51-5ff4-4491-b0e5-b386f32c0992 - Changed how flame shoc...AutoLoL: AutoLoL v1.5.3: A message will be displayed when there's an update available Shows a list of recent mastery files in the Editor Tab (requested by quite a few people) Updater: Update information is now scrollable Added a buton to launch AutoLoL after updating is finished Updated the UI to match that of AutoLoL Fix: Detects and resolves 'Read Only' state on Version.xmlHawkeye - The .Net Runtime Object Editor: Hawkeye 1.2.4: [EDIT: 2010/01/10] In the case you are running an x86 Windows; please wait until Release 1.2.5 is made available: Hawkeye is broken on these OS. This is a maintenance release providing bug fixes. It comes in two flavors: Hawkeye.124.N2 is the standard .NET 2 build, was compiled with Visual Studio 2005 and can only inspect .NET 2 applications. Hawkeye.124.N4 is a .NET4 2 build, was compiled with Visual Studio 2010 and can only inspect .NET 4 applications. Please be patient until Release 1.3...Extended WPF Toolkit: Extended WPF Toolkit - 1.3.0: What's in the 1.3.0 Release?BusyIndicator ButtonSpinner ChildWindow ColorPicker - Updated (Breaking Changes) DateTimeUpDown - New Control Magnifier - New Control MaskedTextBox - New Control MessageBox NumericUpDown RichTextBox RichTextBoxFormatBar - Updated .NET 3.5 binaries and SourcePlease note: The Extended WPF Toolkit 3.5 is dependent on .NET Framework 3.5 and the WPFToolkit. You must install .NET Framework 3.5 and the WPFToolkit in order to use any features in the To...sNPCedit: sNPCedit v0.9d: added elementclient coordinate catcher to catch coordinates select a target (ingame) i.e. your char, npc or monster than click the button and coordinates+direction will be transfered to the selected row in the table corrected labels from Rot to Direction (because it is a vector)Ionics Isapi Rewrite Filter: 2.1 latest stable: V2.1 is stable, and is in maintenance mode. This is v2.1.1.25. It is a bug-fix release. There are no new features. 28629 29172 28722 27626 28074 29164 27659 27900 many documentation updates and fixes proper x64 build environment. This release includes x64 binaries in zip form, but no x64 MSI file. You'll have to manually install x64 servers, following the instructions in the documentation.StyleCop for ReSharper: StyleCop for ReSharper 5.1.14980.000: A considerable amount of work has gone into this release: Huge focus on performance around the violation scanning subsystem: - caching added to reduce IO operations around reading and merging of settings files - caching added to reduce creation of expensive objects Users should notice condsiderable perf boost and a decrease in memory usage. Bug Fixes: - StyleCop's new ObjectBasedEnvironment object does not resolve the StyleCop installation path, thus it does not return the correct path ...VivoSocial: VivoSocial 7.4.1: New release with bug fixes and updates for performance..NET Extensions - Extension Methods Library for C# and VB.NET: Release 2011.03: Added lot's of new extensions and new projects for MVC and Entity Framework. object.FindTypeByRecursion Int32.InRange String.RemoveAllSpecialCharacters String.IsEmptyOrWhiteSpace String.IsNotEmptyOrWhiteSpace String.IfEmptyOrWhiteSpace String.ToUpperFirstLetter String.GetBytes String.ToTitleCase String.ToPlural DateTime.GetDaysInYear DateTime.GetPeriodOfDay IEnumberable.RemoveAll IEnumberable.Distinct ICollection.RemoveAll IList.Join IList.Match IList.Cast Array.IsNullOrEmpty Array.W...EFMVC - ASP.NET MVC 3 and EF Code First: EFMVC 0.5- ASP.NET MVC 3 and EF Code First: Demo web app ASP.NET MVC 3, Razor and EF Code FirstVidCoder: 0.8.0: Added x64 version. Made the audio output preview more detailed and accurate. If the chosen encoder or mixdown is incompatible with the source, the fallback that will be used is displayed. Added "Auto" to the audio mixdown choices. Reworked non-anamorphic size calculation to work better with non-standard pixel aspect ratios and cropping. Reworked Custom anamorphic to be more intuitive and allow display width to be set automatically (Thanks, Statick). Allowing higher bitrates for 6-ch....NET Voice Recorder: Auto-Tune Release: This is the source code and binaries to accompany the article on the Coding 4 Fun website. It is the Auto Tuner release of the .NET Voice Recorder application.BloodSim: BloodSim - 1.3.2.0: - Simulation Log is now automatically disabled and hidden when running 10 or more iterations - Hit and Expertise are now entered by Rating, and include option for a Racial Expertise bonus - Added option for boss to use a periodic magic ability (Dragon Breath) - Added option for boss to periodically Enrage, gaining a Damage/Attack Speed buffJson.NET: Json.NET 4.0 Release 1: New feature - Added Windows Phone 7 project New feature - Added dynamic support to LINQ to JSON New feature - Added dynamic support to serializer New feature - Added INotifyCollectionChanged to JContainer in .NET 4 build New feature - Added ReadAsDateTimeOffset to JsonReader New feature - Added ReadAsDecimal to JsonReader New feature - Added covariance to IJEnumerable type parameter New feature - Added XmlSerializer style Specified property support New feature - Added ...New ProjectsAssimpXna: AssimpXna is a custom model importer for Xna 4.0 using the Open Asset Import Library (Assimp).ATCSim: This is an atc sim for a school projectAzure Role-Based Deployment: Azure Role-Based Deployment demonstrates how to use the CreateDeployment Windows Azure Service Management API to deploy an app from within a web role. This code can easily be ported to a worker role and thus included in the managment pack for a hosted service.CodeKata AltNet Hispano: Ejemplos de Code Kata usados por la comunidad AltNet Hispano.DataStoreCleaner: DataStoreCleaner clears "DataStore" folder which manages Windows Update History. It is useful for fixing WU error, or tune up Windows start-up. It's developed in C#.DS_HW2: dshw2EFT Calculator: EFT Calculator is an application that performs common cryptographic operations used in electronic funds transfer applications.Entity Visualizers: This project has debugger visualizers for several objects in the Entity Framework: EntityObject, EntityCollection, ObjectQuery and ObjectContext. Some of the source code is based on code from Julie Lerman's book "Programming Entity Framework".EzyCMS - Easy and Simple CMS made by ASP.Net MVC: EzyCMS makes both of end user and developer enjoy CMS benefit and extendability to perform requirements. The design principles: EASY TO USE, EASY TO EXTEND, FLEXIBLE AND PWOERFUL TECHNOLOGY: ASP.Net MVC2, NHibernate, StructureMap, JQueryFlatStore: Simple library to simplify storage of application data when a bulky dedicated database is cumbersome and unnecessaryGigantornis: Gigantornis is a tool for benchmarking your Hypertext Transfer Protocol (HTTP) server. It is designed to give you an impression of how your current server installation performs. This especially shows you how many requests per second your server installation is capable of serving.Gonte.Dal: Data access layer for NETLezatrus: Lezatrus is the open source project to help people find places to eat in Jakarta. It's developed in ASP.NET MVC using Razor and C#. It's the sample app for Pro ASP.NET MVC Coding Ninja facebook group.Moo: Moo is an object-to-object multi-mapper. It is able to use multiple different strategies (in a mix of convention, configuration, attributes and fluent calls) when mapping from one object to another.MvcXaml: A custom View Engine for ASP.NET MVC that allows Controller Action Methods to return dynamically generated images based on XAML markup.Perfect World Bot Development FrameWork: <empty yet>Silverlight motion detection: Motion detection using Silverlight 4 camera support and a simple motion detection algorithm.Small IT Business Manager: Small IT Business Manager is a tool being created keeping small-midsize IT companies in mind to allow them manage their day to day chores. Management Features planned: * Workers * Timesheets * Financial * HR * Basic Project Management * Invoicingsomething for testing: mot do an mau de test cac van de lien quan toi codeStructure Copier: This small program is supposed to copy tree structure of directory.TogNet: A small utility program to toggle between windows network adapters. Needed a program like this to switch between an external Wireless network and the corporate Lan network adapter.

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• Microsoft&rsquo;s new technical computing initiative

  - by Randy Walker

  I made a mental note from earlier in the year.  Microsoft literally buys computers by the truckload.  From what I understand, it’s a typical practice amongst large software vendors.  You plug a few wires in, you test it, and you instantly have mega tera tera flops (don’t hold me to that number).  Microsoft has been trying to plug away at their cloud services (named Azure).  Which, for the layman, means Microsoft runs your software on their computers, and as demand increases you can allocate more computing power on the fly. With this in mind, it doesn’t surprise me that I was recently sent an executive email concerning Microsoft’s new technical computing initiative.  I find it to be a great marketing idea with actual substance behind their real work.  From the programmer academic perspective, in college we dreamed about this type of processing power.  This has decades of computer science theory behind it. A copy of the email received.  (note that I almost deleted this email, thinking it was spam due to it’s length) We don't often think about how complex life really is. Take the relatively simple task of commuting to and from work: it is, in fact, a complicated interplay of variables such as weather, train delays, accidents, traffic patterns, road construction, etc. You can however, take steps to shorten your commute - using a good, predictive understanding of a few of these variables. In fact, you probably are already taking these inputs and instinctively building a predictive model that you act on daily to get to your destination more quickly. Now, when we apply the same method to very complex tasks, this modeling approach becomes much more challenging. Recent world events clearly demonstrated our inability to process vast amounts of information and variables that would have helped to more accurately predict the behavior of global financial markets or the occurrence and impact of a volcano eruption in Iceland. To make sense of issues like these, researchers, engineers and analysts create computer models of the almost infinite number of possible interactions in complex systems. But, they need increasingly more sophisticated computer models to better understand how the world behaves and to make fact-based predictions about the future. And, to do this, it requires a tremendous amount of computing power to process and examine the massive data deluge from cameras, digital sensors and precision instruments of all kinds. This is the key to creating more accurate and realistic models that expose the hidden meaning of data, which gives us the kind of insight we need to solve a myriad of challenges. We have made great strides in our ability to build these kinds of computer models, and yet they are still too difficult, expensive and time consuming to manage. Today, even the most complicated data-rich simulations cannot fully capture all of the intricacies and dependencies of the systems they are trying to model. That is why, across the scientific and engineering world, it is so hard to say with any certainty when or where the next volcano will erupt and what flight patterns it might affect, or to more accurately predict something like a global flu pandemic. So far, we just cannot collect, correlate and compute enough data to create an accurate forecast of the real world. But this is about to change. Innovations in technology are transforming our ability to measure, monitor and model how the world behaves. The implication for scientific research is profound, and it will transform the way we tackle global challenges like health care and climate change. It will also have a huge impact on engineering and business, delivering breakthroughs that could lead to the creation of new products, new businesses and even new industries. Because you are a subscriber to executive e-mails from Microsoft, I want you to be the first to know about a new effort focused specifically on empowering millions of the world's smartest problem solvers. Today, I am happy to introduce Microsoft's Technical Computing initiative. Our goal is to unleash the power of pervasive, accurate, real-time modeling to help people and organizations achieve their objectives and realize their potential. We are bringing together some of the brightest minds in the technical computing community across industry, academia and science at www.modelingtheworld.com to discuss trends, challenges and shared opportunities. New advances provide the foundation for tools and applications that will make technical computing more affordable and accessible where mathematical and computational principles are applied to solve practical problems. One day soon, complicated tasks like building a sophisticated computer model that would typically take a team of advanced software programmers months to build and days to run, will be accomplished in a single afternoon by a scientist, engineer or analyst working at the PC on their desktop. And as technology continues to advance, these models will become more complete and accurate in the way they represent the world. This will speed our ability to test new ideas, improve processes and advance our understanding of systems. Our technical computing initiative reflects the best of Microsoft's heritage. Ever since Bill Gates articulated the then far-fetched vision of "a computer on every desktop" in the early 1980's, Microsoft has been at the forefront of expanding the power and reach of computing to benefit the world. As someone who worked closely with Bill for many years at Microsoft, I am happy to share with you that the passion behind that vision is fully alive at Microsoft and is carried out in the creation of our new Technical Computing group. Enabling more people to make better predictions We have seen the impact of making greater computing power more available firsthand through our investments in high performance computing (HPC) over the past five years. Scientists, engineers and analysts in organizations of all sizes and sectors are finding that using distributed computational power creates societal impact, fuels scientific breakthroughs and delivers competitive advantages. For example, we have seen remarkable results from some of our current customers: Malaria strikes 300,000 to 500,000 people around the world each year. To help in the effort to eradicate malaria worldwide, scientists at Intellectual Ventures use software that simulates how the disease spreads and would respond to prevention and control methods, such as vaccines and the use of bed nets. Technical computing allows researchers to model more detailed parameters for more accurate results and receive those results in less than an hour, rather than waiting a full day. Aerospace engineering firm, a.i. solutions, Inc., needed a more powerful computing platform to keep up with the increasingly complex computational needs of its customers: NASA, the Department of Defense and other government agencies planning space flights. To meet that need, it adopted technical computing. Now, a.i. solutions can produce detailed predictions and analysis of the flight dynamics of a given spacecraft, from optimal launch times and orbit determination to attitude control and navigation, up to eight times faster. This enables them to avoid mistakes in any areas that can cause a space mission to fail and potentially result in the loss of life and millions of dollars. Western & Southern Financial Group faced the challenge of running ever larger and more complex actuarial models as its number of policyholders and products grew and regulatory requirements changed. The company chose an actuarial solution that runs on technical computing technology. The solution is easy for the company's IT staff to manage and adjust to meet business needs. The new solution helps the company reduce modeling time by up to 99 percent - letting the team fine-tune its models for more accurate product pricing and financial projections. Our Technical Computing direction Collaborating closely with partners across industry and academia, we must now extend the reach of technical computing even further to help predictive modelers and data explorers make faster, more accurate predictions. As we build the Technical Computing initiative, we will invest in three core areas: Technical computing to the cloud: Microsoft will play a leading role in bringing technical computing power to scientists, engineers and analysts through the cloud. Existing high- performance computing users will benefit from the ability to augment their on-premises systems with cloud resources that enable 'just-in-time' processing. This platform will help ensure processing resources are available whenever they are needed-reliably, consistently and quickly. Simplify parallel development: Today, computers are shipping with more processing power than ever, including multiple cores, but most modern software only uses a small amount of the available processing power. Parallel programs are extremely difficult to write, test and trouble shoot. However, a consistent model for parallel programming can help more developers unlock the tremendous power in today's modern computers and enable a new generation of technical computing. We are delivering new tools to automate and simplify writing software through parallel processing from the desktop... to the cluster... to the cloud. Develop powerful new technical computing tools and applications: We know scientists, engineers and analysts are pushing common tools (i.e., spreadsheets and databases) to the limits with complex, data-intensive models. They need easy access to more computing power and simplified tools to increase the speed of their work. We are building a platform to do this. Our development efforts will yield new, easy-to-use tools and applications that automate data acquisition, modeling, simulation, visualization, workflow and collaboration. This will allow them to spend more time on their work and less time wrestling with complicated technology. Thinking bigger There is so much left to be discovered and so many questions yet to be answered in the fascinating world around us. We believe the technical computing community will show us that we have not seen anything yet. Imagine just some of the breakthroughs this community could make possible: Better predictions to help improve the understanding of pandemics, contagion and global health trends. Climate change models that predict environmental, economic and human impact, accessible in real-time during key discussions and debates. More accurate prediction of natural disasters and their impact to develop more effective emergency response plans. With an ambitious charter in hand, this new team is ready to build on our progress to-date and execute Microsoft's technical computing vision over the months and years ahead. We will steadily invest in the right technologies, tools and talent, and work to bring together the technical computing community. I invite you to visit www.modelingtheworld.com today. We welcome your ideas and feedback. I look forward to making this journey with you and others who want to answer the world's biggest questions, discover solutions to problems that seem impossible and uncover a host of new opportunities to change the world we live in for the better. Bob

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• Right-Time Retail Part 3

  - by David Dorf

  This is part three of the three-part series.  Read Part 1 and Part 2 first. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Right-Time Marketing Real-time isn’t just about executing faster; it extends to interactions with customers as well. As an industry, we’ve spent many years analyzing all the data that’s been collected. Yes, that data has been invaluable in helping us make better decisions like where to open new stores, how to assort those stores, and how to price our products. But the recent advances in technology are now making it possible to analyze and deliver that data very quickly… fast enough to impact a potential sale in near real-time. Let me give you two examples. Salesmen in car dealerships get pretty good at sizing people up. When a potential customer walks in the door, it doesn’t take long for the salesman to figure out the revenue at stake. Is this person a real buyer, or just looking for a fun test drive? Will this person buy today or three months from now? Will this person opt for the expensive packages, or go bare bones? While the salesman certainly asks some leading questions, much of information is discerned through body language. But body language doesn’t translate very well over the web. Eloqua, which was acquired by Oracle earlier this year, reads internet body language. By tracking the behavior of the people visiting your web site, Eloqua categorizes visitors based on their propensity to buy. While Eloqua’s roots have been in B2B, we’ve been looking at leveraging the technology with ATG to target B2C. Knowing what sites were previously visited, how often the customer has been to your site recently, and how long they’ve spent searching can help understand where the customer is in their purchase journey. And knowing that bit of information may be enough to help close the deal with a real-time offer, follow-up email, or online customer service pop-up. This isn’t so different from the days gone by when the clerk behind the counter of the corner store noticed you were lingering in a particular aisle, so he walked over to help you compare two products and close the sale. You appreciated the personalized service, and he knew the value of the long-term relationship. Move that same concept into the digital world and you have Oracle’s CX Suite, a cloud-based offering of end-to-end customer experience tools, assembled primarily from acquisitions. Those tools are Oracle Marketing (Eloqua), Oracle Commerce (ATG, Endeca), Oracle Sales (Oracle CRM On Demand), Oracle Service (RightNow), Oracle Social (Collective Intellect, Vitrue, Involver), and Oracle Content (Fatwire). We are providing the glue that binds the CIO and CMO together to unleash synergies that drive the top-line higher, and by virtue of the cloud-approach, keep costs at bay. My second example of real-time marketing takes place in the store but leverages the concepts of Web marketing. In 1962 the decline of personalized service in retail began. Anyone know the significance of that year? That’s when Target, K-Mart, and Walmart each opened their first stores, and over the succeeding years the industry chose scale over personal service. No longer were you known as “Jane with the snotty kid so make sure we check her out fast,” but you suddenly became “time-starved female age 20-30 with kids.” I’m not saying that was a bad thing – it was the right thing for our industry at the time, and it enabled a huge amount of growth, cheaper prices, and more variety of products. But scale alone is no longer good enough. Today’s sophisticated consumer demands scale, experience, and personal attention. To some extent we’ve delivered that on websites via the magic of cookies, your willingness to log in, and sophisticated data analytics. What store manager wouldn’t love a report detailing all the visitors to his store, where they came from, and which products that examined? People trackers are getting more sophisticated, incorporating infrared, video analytics, and even face recognition. (Next time you walk in front on a mannequin, don’t be surprised if it’s looking back.) But the ultimate marketing conduit is the mobile phone. Since each mobile phone emits a unique number on WiFi networks, it becomes the cookie of the physical world. Assuming congress keeps privacy safeguards reasonable, we’ll have a win-win situation for both retailers and consumers. Retailers get to know more about the consumer’s purchase journey, and consumers get higher levels of service with the retailer. When I call my bank, a couple things happen before the call is connected. A reverse look-up on my phone number identifies me so my accounts can be retrieved from Siebel CRM. Then the system anticipates why I’m calling based on recent transactions. In this example, it sees that I was just charged a foreign currency fee, so it assumes that’s the reason I’m calling. It puts all the relevant information on the customer service rep’s screen as it connects the call. When I complain about the fee, the rep immediately sees I’m a great customer and I travel lots, so she suggests switching me to their traveler’s card that doesn’t have foreign transaction fees. That technology is powered by a product called Oracle Real-Time Decisions, a rules engine built to execute very quickly, basically in the time it takes the phone to ring once. So let’s combine the power of that product with our new-found mobile cookie and provide contextual customer interactions in real-time. Our first opportunity comes when a customer crosses a pre-defined geo-fence, typically a boundary around the store. Context is the key to our interaction: that’s the customer (known or anonymous), the time of day and day of week, and location. Thomas near the downtown store on a Wednesday at noon means he’s heading to lunch. If he were near the mall location on a Saturday morning, that’s a completely different context. But on his way to lunch, we’ll let Thomas know that we’ve got a new shipment of ASICS running shoes on display with a simple text message. We used the context to look-up Thomas’ past purchases and understood he was an avid runner. We used the fact that this was lunchtime to select the type of message, in this case an informational message instead of an offer. Thomas enters the store, phone in hand, and walks to the shoe department. He scans one of the new ASICS shoes using the convenient QR Codes we provided on the shelf-tags, but then he starts scanning low-end Nikes. Each scan is another opportunity to both learn from Thomas and potentially interact via another message. Since he historically buys low-end Nikes and keeps scanning them, he’s likely falling back into his old ways. Our marketing rules are currently set to move loyal customer to higher margin products. We could have set the dials to increase visit frequency, move overstocked items, increase basket size, or many other settings, but today we are trying to move Thomas to higher-margin products. We send Thomas another text message, this time it’s a personalized offer for 10% off ASICS good for 24 hours. Offering him a discount on Nikes would be throwing margin away since he buys those anyway. We are using our marketing dollars to change behavior that increases the long-term value of Thomas. He decides to buy the ASICS and scans the discount code on his phone at checkout. Checkout is yet another opportunity to interact with Thomas, so the transaction is sent back to Oracle RTD for evaluation. Since Thomas didn’t buy anything with the shoes, we’ll print a bounce-back coupon on the receipt offering 30% off ASICS socks if he returns within seven days. We have successfully started moving Thomas from low-margin to high-margin products. In both of these marketing scenarios, we are able to leverage data in near real-time to decide how best to interact with the customer and lead to an increase in the lifetime value of the customer. The key here is acting at the moment the customer shows interest using the context of the situation. We aren’t pushing random products at haphazard times. We are tailoring the marketing to be very specific to this customer, and it’s the technology that allows this to happen in near real-time. Conclusion As we enable more right-time integrations and interactions, retailers will begin to offer increased service to their customers. Localized and personalized service at scale will drive loyalty and lead to meaningful revenue growth for the retailers that execute well. Our industry needs to support Commerce Anywhere…and commerce anytime as well.

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• Recommended ASP.NET Shared Hosting (USA)

  - by coffeeaddict

  Ok, I have to admit I'm getting fed up with www.discountasp.net's pricing model and this annoyance has built up over the past 8 years or so. I've been with them for years and absolutely love them on the technical side, however it's getting ridiculously expensive for so little that you get. I mean here's my scenario: 1) I am running 2 SQL Server databases which costs me $10/ea per month so that's $20/month for 2 and I only get 500 mb disk space which is horrible 2) I am paying $10/mo just for the hosting itself which I only get 1 gig of disk space! I mean common! 3) I am simply running 2 small apps (Screwturn Wiki & Subtext Blog)...so I don't really care if it's up 99% or not, it's not worth paying a total of $300 just to keep these 2 apps running over discountasp.net Anyone else feel the same? Yes, I know they have great support, probably have great servers running behind this but in the end I really don't care as long as my site is up 95% or better. Yes, the hosting toolset rocks. But you know I bet you I can find a similar set somewhere else. I like how I can totally control IIS 7 at discountasp and I can control my own app pool etc. That's very powerful and essential. But anyone have any good alternatives to discountasp that gives me close to the same at a much more reasonable cost point? I mean http://www.m6.net/prices.aspx gives you 10 SQL Databases for $7 and 200 gigs disk space! I don't know about their tools or support but just looking at those numbers and some other hosts I've seen, I feel that discountasp.net is way out of line. They don't even offer any purchasing discounts such as it would be nice if my 2nd SQL Server is only $5/month not $10...stuff like this, to make it much more realistic and fair. Opinions (people who do have discountasp.net, people who have left them, or people who have another host they like)??? But geez $300 just to host a couple DBs and lightweight open source apps? Not worth the price they are charging. I'm almost at a price point that enables me to get a decent dedicated server! I really don't care about beta ASP.NET frameworks support. Not a big deal to me. If you have alternative suggestions rather than your experience with discountasp, I'd like to know how their toolset is. Do you have complete control over your DB in terms of adding users, and same goes for the web app pool, etc.? Discountasp.net's control panel rocks. I don't want to loose the ability to at least control and add virtual directories, recycle my dedicated app pool myself, backup my sql database myself, through tools which is what discountasp does give you. I'd also want to know that the hoster at least gets the latest and greatest in terms of non-beta ASP.NET related frameworks available to its shared hosters.

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• Spooling in SQL execution plans

  - by Rob Farley

  Sewing has never been my thing. I barely even know the terminology, and when discussing this with American friends, I even found out that half the words that Americans use are different to the words that English and Australian people use. That said – let’s talk about spools! In particular, the Spool operators that you find in some SQL execution plans. This post is for T-SQL Tuesday, hosted this month by me! I’ve chosen to write about spools because they seem to get a bad rap (even in my song I used the line “There’s spooling from a CTE, they’ve got recursion needlessly”). I figured it was worth covering some of what spools are about, and hopefully explain why they are remarkably necessary, and generally very useful. If you have a look at the Books Online page about Plan Operators, at http://msdn.microsoft.com/en-us/library/ms191158.aspx, and do a search for the word ‘spool’, you’ll notice it says there are 46 matches. 46! Yeah, that’s what I thought too... Spooling is mentioned in several operators: Eager Spool, Lazy Spool, Index Spool (sometimes called a Nonclustered Index Spool), Row Count Spool, Spool, Table Spool, and Window Spool (oh, and Cache, which is a special kind of spool for a single row, but as it isn’t used in SQL 2012, I won’t describe it any further here). Spool, Table Spool, Index Spool, Window Spool and Row Count Spool are all physical operators, whereas Eager Spool and Lazy Spool are logical operators, describing the way that the other spools work. For example, you might see a Table Spool which is either Eager or Lazy. A Window Spool can actually act as both, as I’ll mention in a moment. In sewing, cotton is put onto a spool to make it more useful. You might buy it in bulk on a cone, but if you’re going to be using a sewing machine, then you quite probably want to have it on a spool or bobbin, which allows it to be used in a more effective way. This is the picture that I want you to think about in relation to your data. I’m sure you use spools every time you use your sewing machine. I know I do. I can’t think of a time when I’ve got out my sewing machine to do some sewing and haven’t used a spool. However, I often run SQL queries that don’t use spools. You see, the data that is consumed by my query is typically in a useful state without a spool. It’s like I can just sew with my cotton despite it not being on a spool! Many of my favourite features in T-SQL do like to use spools though. This looks like a very similar query to before, but includes an OVER clause to return a column telling me the number of rows in my data set. I’ll describe what’s going on in a few paragraphs’ time. So what does a Spool operator actually do? The spool operator consumes a set of data, and stores it in a temporary structure, in the tempdb database. This structure is typically either a Table (ie, a heap), or an Index (ie, a b-tree). If no data is actually needed from it, then it could also be a Row Count spool, which only stores the number of rows that the spool operator consumes. A Window Spool is another option if the data being consumed is tightly linked to windows of data, such as when the ROWS/RANGE clause of the OVER clause is being used. You could maybe think about the type of spool being like whether the cotton is going onto a small bobbin to fit in the base of the sewing machine, or whether it’s a larger spool for the top. A Table or Index Spool is either Eager or Lazy in nature. Eager and Lazy are Logical operators, which talk more about the behaviour, rather than the physical operation. If I’m sewing, I can either be all enthusiastic and get all my cotton onto the spool before I start, or I can do it as I need it. “Lazy” might not the be the best word to describe a person – in the SQL world it describes the idea of either fetching all the rows to build up the whole spool when the operator is called (Eager), or populating the spool only as it’s needed (Lazy). Window Spools are both physical and logical. They’re eager on a per-window basis, but lazy between windows. And when is it needed? The way I see it, spools are needed for two reasons. 1 – When data is going to be needed AGAIN. 2 – When data needs to be kept away from the original source. If you’re someone that writes long stored procedures, you are probably quite aware of the second scenario. I see plenty of stored procedures being written this way – where the query writer populates a temporary table, so that they can make updates to it without risking the original table. SQL does this too. Imagine I’m updating my contact list, and some of my changes move data to later in the book. If I’m not careful, I might update the same row a second time (or even enter an infinite loop, updating it over and over). A spool can make sure that I don’t, by using a copy of the data. This problem is known as the Halloween Effect (not because it’s spooky, but because it was discovered in late October one year). As I’m sure you can imagine, the kind of spool you’d need to protect against the Halloween Effect would be eager, because if you’re only handling one row at a time, then you’re not providing the protection... An eager spool will block the flow of data, waiting until it has fetched all the data before serving it up to the operator that called it. In the query below I’m forcing the Query Optimizer to use an index which would be upset if the Name column values got changed, and we see that before any data is fetched, a spool is created to load the data into. This doesn’t stop the index being maintained, but it does mean that the index is protected from the changes that are being done. There are plenty of times, though, when you need data repeatedly. Consider the query I put above. A simple join, but then counting the number of rows that came through. The way that this has executed (be it ideal or not), is to ask that a Table Spool be populated. That’s the Table Spool operator on the top row. That spool can produce the same set of rows repeatedly. This is the behaviour that we see in the bottom half of the plan. In the bottom half of the plan, we see that the a join is being done between the rows that are being sourced from the spool – one being aggregated and one not – producing the columns that we need for the query. Table v Index When considering whether to use a Table Spool or an Index Spool, the question that the Query Optimizer needs to answer is whether there is sufficient benefit to storing the data in a b-tree. The idea of having data in indexes is great, but of course there is a cost to maintaining them. Here we’re creating a temporary structure for data, and there is a cost associated with populating each row into its correct position according to a b-tree, as opposed to simply adding it to the end of the list of rows in a heap. Using a b-tree could even result in page-splits as the b-tree is populated, so there had better be a reason to use that kind of structure. That all depends on how the data is going to be used in other parts of the plan. If you’ve ever thought that you could use a temporary index for a particular query, well this is it – and the Query Optimizer can do that if it thinks it’s worthwhile. It’s worth noting that just because a Spool is populated using an Index Spool, it can still be fetched using a Table Spool. The details about whether or not a Spool used as a source shows as a Table Spool or an Index Spool is more about whether a Seek predicate is used, rather than on the underlying structure. Recursive CTE I’ve already shown you an example of spooling when the OVER clause is used. You might see them being used whenever you have data that is needed multiple times, and CTEs are quite common here. With the definition of a set of data described in a CTE, if the query writer is leveraging this by referring to the CTE multiple times, and there’s no simplification to be leveraged, a spool could theoretically be used to avoid reapplying the CTE’s logic. Annoyingly, this doesn’t happen. Consider this query, which really looks like it’s using the same data twice. I’m creating a set of data (which is completely deterministic, by the way), and then joining it back to itself. There seems to be no reason why it shouldn’t use a spool for the set described by the CTE, but it doesn’t. On the other hand, if we don’t pull as many columns back, we might see a very different plan. You see, CTEs, like all sub-queries, are simplified out to figure out the best way of executing the whole query. My example is somewhat contrived, and although there are plenty of cases when it’s nice to give the Query Optimizer hints about how to execute queries, it usually doesn’t do a bad job, even without spooling (and you can always use a temporary table). When recursion is used, though, spooling should be expected. Consider what we’re asking for in a recursive CTE. We’re telling the system to construct a set of data using an initial query, and then use set as a source for another query, piping this back into the same set and back around. It’s very much a spool. The analogy of cotton is long gone here, as the idea of having a continual loop of cotton feeding onto a spool and off again doesn’t quite fit, but that’s what we have here. Data is being fed onto the spool, and getting pulled out a second time when the spool is used as a source. (This query is running on AdventureWorks, which has a ManagerID column in HumanResources.Employee, not AdventureWorks2012) The Index Spool operator is sucking rows into it – lazily. It has to be lazy, because at the start, there’s only one row to be had. However, as rows get populated onto the spool, the Table Spool operator on the right can return rows when asked, ending up with more rows (potentially) getting back onto the spool, ready for the next round. (The Assert operator is merely checking to see if we’ve reached the MAXRECURSION point – it vanishes if you use OPTION (MAXRECURSION 0), which you can try yourself if you like). Spools are useful. Don’t lose sight of that. Every time you use temporary tables or table variables in a stored procedure, you’re essentially doing the same – don’t get upset at the Query Optimizer for doing so, even if you think the spool looks like an expensive part of the query. I hope you’re enjoying this T-SQL Tuesday. Why not head over to my post that is hosting it this month to read about some other plan operators? At some point I’ll write a summary post – once I have you should find a comment below pointing at it. @rob_farley

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• CodePlex Daily Summary for Saturday, January 08, 2011

  CodePlex Daily Summary for Saturday, January 08, 2011Popular ReleasesExtended WPF Toolkit: Extended WPF Toolkit - 1.3.0: What's in the 1.3.0 Release?BusyIndicator ButtonSpinner ChildWindow ColorPicker - Updated (Breaking Changes) DateTimeUpDown - New Control Magnifier - New Control MaskedTextBox - New Control MessageBox NumericUpDown RichTextBox RichTextBoxFormatBar - Updated .NET 3.5 binaries and SourcePlease note: The Extended WPF Toolkit 3.5 is dependent on .NET Framework 3.5 and the WPFToolkit. You must install .NET Framework 3.5 and the WPFToolkit in order to use any features in the To...sNPCedit: sNPCedit v0.9d: added elementclient coordinate catcher to catch coordinates select a target (ingame) i.e. your char, npc or monster than click the button and coordinates+direction will be transfered to the selected row in the table corrected labels from Rot to Direction (because it is a vector)AutoLoL: AutoLoL v1.5.2: Implemented the Auto Updater Fix: Your settings will no longer be cleared with new releases of AutoLoL The mastery Editor and Browser now have their own tabs instead of nested tabs The Browser tab will only show the masteries matching ALL filters instead of just one Added a 'Browse' button in the Mastery Editor tab to open the Masteries Directory The Browser tab now shows a message when there are no mastery files in the Masteries Directory Fix: Fixed the Save As dialog again, for ...Ionics Isapi Rewrite Filter: 2.1 latest stable: V2.1 is stable, and is in maintenance mode. This is v2.1.1.25. It is a bug-fix release. There are no new features. 28629 29172 28722 27626 28074 29164 27659 27900 many documentation updates and fixes proper x64 build environment. This release includes x64 binaries in zip form, but no x64 MSI file. You'll have to manually install x64 servers, following the instructions in the documentation.StyleCop for ReSharper: StyleCop for ReSharper 5.1.14980.000: A considerable amount of work has gone into this release: Huge focus on performance around the violation scanning subsystem: - caching added to reduce IO operations around reading and merging of settings files - caching added to reduce creation of expensive objects Users should notice condsiderable perf boost and a decrease in memory usage. Bug Fixes: - StyleCop's new ObjectBasedEnvironment object does not resolve the StyleCop installation path, thus it does not return the correct path ...VivoSocial: VivoSocial 7.4.1: New release with bug fixes and updates for performance.SSH.NET Library: 2011.1.6: Fixes CommandTimeout default value is fixed to infinite. Port Forwarding feature improvements Memory leaks fixes New Features Add ErrorOccurred event to handle errors that occurred on different thread New and improve SFTP features SftpFile now has more attributes and some operations Most standard operations now available Allow specify encoding for command execution KeyboardInteractiveConnectionInfo class added for "keyboard-interactive" authentication. Add ability to specify bo....NET Extensions - Extension Methods Library for C# and VB.NET: Release 2011.03: Added lot's of new extensions and new projects for MVC and Entity Framework. object.FindTypeByRecursion Int32.InRange String.RemoveAllSpecialCharacters String.IsEmptyOrWhiteSpace String.IsNotEmptyOrWhiteSpace String.IfEmptyOrWhiteSpace String.ToUpperFirstLetter String.GetBytes String.ToTitleCase String.ToPlural DateTime.GetDaysInYear DateTime.GetPeriodOfDay IEnumberable.RemoveAll IEnumberable.Distinct ICollection.RemoveAll IList.Join IList.Match IList.Cast Array.IsNullOrEmpty Array.W...VidCoder: 0.8.0: Added x64 version. Made the audio output preview more detailed and accurate. If the chosen encoder or mixdown is incompatible with the source, the fallback that will be used is displayed. Added "Auto" to the audio mixdown choices. Reworked non-anamorphic size calculation to work better with non-standard pixel aspect ratios and cropping. Reworked Custom anamorphic to be more intuitive and allow display width to be set automatically (Thanks, Statick). Allowing higher bitrates for 6-ch....NET Voice Recorder: Auto-Tune Release: This is the source code and binaries to accompany the article on the Coding 4 Fun website. It is the Auto Tuner release of the .NET Voice Recorder application.BloodSim: BloodSim - 1.3.2.0: - Simulation Log is now automatically disabled and hidden when running 10 or more iterations - Hit and Expertise are now entered by Rating, and include option for a Racial Expertise bonus - Added option for boss to use a periodic magic ability (Dragon Breath) - Added option for boss to periodically Enrage, gaining a Damage/Attack Speed buffEnhSim: EnhSim 2.2.9 BETA: 2.2.9 BETAThis release supports WoW patch 4.03a at level 85 To use this release, you must have the Microsoft Visual C++ 2010 Redistributable Package installed. This can be downloaded from http://www.microsoft.com/downloads/en/details.aspx?FamilyID=A7B7A05E-6DE6-4D3A-A423-37BF0912DB84 To use the GUI you must have the .NET 4.0 Framework installed. This can be downloaded from http://www.microsoft.com/downloads/en/details.aspx?FamilyID=9cfb2d51-5ff4-4491-b0e5-b386f32c0992 - Added in the Gobl...xUnit.net - Unit Testing for .NET: xUnit.net 1.7 Beta: xUnit.net release 1.7 betaBuild #1533 Important notes for Resharper users: Resharper support has been moved to the xUnit.net Contrib project. Important note for TestDriven.net users: If you are having issues running xUnit.net tests in TestDriven.net, especially on 64-bit Windows, we strongly recommend you upgrade to TD.NET version 3.0 or later. This release adds the following new features: Added support for ASP.NET MVC 3 Added Assert.Equal(double expected, double actual, int precision)...Json.NET: Json.NET 4.0 Release 1: New feature - Added Windows Phone 7 project New feature - Added dynamic support to LINQ to JSON New feature - Added dynamic support to serializer New feature - Added INotifyCollectionChanged to JContainer in .NET 4 build New feature - Added ReadAsDateTimeOffset to JsonReader New feature - Added ReadAsDecimal to JsonReader New feature - Added covariance to IJEnumerable type parameter New feature - Added XmlSerializer style Specified property support New feature - Added ...DbDocument: DbDoc Initial Version: DbDoc Initial versionASP .NET MVC CMS (Content Management System): Atomic CMS 2.1.2: Atomic CMS 2.1.2 release notes Atomic CMS installation guide N2 CMS: 2.1: N2 is a lightweight CMS framework for ASP.NET. It helps you build great web sites that anyone can update. Major Changes Support for auto-implemented properties ({get;set;}, based on contribution by And Poulsen) All-round improvements and bugfixes File manager improvements (multiple file upload, resize images to fit) New image gallery Infinite scroll paging on news Content templates First time with N2? Try the demo site Download one of the template packs (above) and open the proj...Mobile Device Detection and Redirection: 0.1.11.10: IMPORTANT CHANGESThis release changes the way some WURFL capabilities and attributes are exposed to .NET developers. If you cast MobileCapabilities to return some values then please read the Release Note before implementing this release. The following code snippet can be used to access any WURFL capability. For instance, if the device is a tablet: string capability = Request.Browser["is_tablet"]; SummaryNew attributes have been added to the redirect section: originalUrlAsQueryString If se...Wii Backup Fusion: Wii Backup Fusion 1.0: - Norwegian translation - French translation - German translation - WBFS dump for analysis - Scalable full HQ cover - Support for log file - Load game images improved - Support for image splitting - Diff for images after transfer - Support for scrubbing modes - Search functionality for log - Recurse depth for Files/Load - Show progress while downloading game cover - Supports more databases for cover download - Game cover loading routines improvedBlogEngine.NET: BlogEngine.NET 2.0: Get DotNetBlogEngine for 3 Months Free! Click Here for More Info 3 Months FREE – BlogEngine.NET Hosting – Click Here! If you want to set up and start using BlogEngine.NET right away, you should download the Web project. If you want to extend or modify BlogEngine.NET, you should download the source code. If you are upgrading from a previous version of BlogEngine.NET, please take a look at the Upgrading to BlogEngine.NET 2.0 instructions. To get started, be sure to check out our installatio...New Projects2011 Scripting Games: Track Changes for the 2011 Scripting Games to be hosted on PoshCode by the Microsoft Scripting Guys and the PowerShell community. ADO.NET Unit Testable Repository Generator: Generates a strongly-typed Object Context and POCO Entities from your EDMX file. Additionally a Repository and an abstract Unit Test for the Repository is created (with a mock for the ObjectContext and mock for the ObjectSets). Bases on the "ADO.NET C# POCO Entity Generator".AshpazKhone: ???AVAilable Rooms: AVAilable Rooms Can be used to show and book rooms on an exchange serverContentManager: Content Manger for SAP Kpro exports the data pool of a content-server by PHIOS-Lists (txt-files) into local binary files. Afterwards this files can be imported in a SAP content-repository . The whole List of the PHIOS Keys can also be downloaded an splitted in practical units.CSLauncher: CSLauncher is a small application providing a launching interface similar to Counter Strike's weapons selection menu. You can organize your favorite applications in CSLauncher in the order you wish, then launch them by remembering their numbers.DbMetadata: A simple lightweight library used to retrieve database metadata.DotNetSiemensPLCToolBoxLibrary: DotNetSiemensPLCToolBoxLibrary A Library for working with Siemens Step5 and Step7 Projects, connecting to S5 or S7 PLC's.EmptyX: EmptyX is a game developped with c# and xna for the XNA CHALLENGE in AlgeriaERASMUS: Erasmus šitFaceDeBouc: Simplebook, le nouveau Facebook CPE! Technlogies .NET Serveur: - BDD SQLServer - Logique métier - Web services Clients: - client lourd WPF - client léger ASP.NETFunction resolver: Application using .NET Expression trees to resolve a function for a set of numbersMLRobotic: Programme de gestion MLRobotic 2011 Sissa ProjectMS CRM Multiple Attachment Download Application: Microsoft Dynamics CRM 4.0 currently does not have a built in way for CRM Administrators to Export multiple attachments from the database and store it on a local directory on the Server or the local PC. This application allows you to do so.Open Data Publisher: Open Data Publisher is a C# MVC application that allows you to quickly and easily publish data from SQL Server tables and views using the OData protocol, and present data from OData and static sources to the public for download and exploration.OttawaZagreb1: Test projectPrague: ????? ?? ???? ??????PSSplunk: PSSplunk is a set of Powershell cmdlets that use the RESTFUL API provided by www.splunk.com The goal is provide access to all of Splunks configuration and search features from the CLI without having to have Splunk installed locally.Reactive C#: Reactive language extensions for C#SemanaWebcasts: Projeto para semana de webcasts.Steward: Personal StewardSVNUG.Tracker: SVNUG.Tracker is an example task tracking application used as a presentation project for the Sangamon Valley .NET User Group (svnug.com). The purpose of SVNUG.Tracker is to be a common problem domain for exercising new .NET technology. SVNUG.Tracker is written in C# 4.The Silverlight Cookbook - A Reference Application for Silverlight 4 LOB Apps: The Silverlight Cookbook is a .NET example application that demonstrates how to build a full-blown line-of-business app using the reference architecture explained at: http://www.dennisdoomen.net/search/label/Silverlight Vkontakte Wpf Client: This is a simple client for social network Vkontakte. It can send message to your friends, download audio files or play it,list user video. Also you can view user status and change yours.Windows Phone Multilingual Keyboard: Multilingual keyboard for Windows Phone 7WPF Controls & MVVM Practices: WPF Controls contains various controls that can be used in applications. Currently Featured * FilteredListBox (filter and selected items notification) * IsDirty functionality for a ViewModel model

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• Using a portable USB monitor in Ubuntu 13.04 (AOC e1649Fwu - DisplayLink)

  Having access to a little bit of IT hardware extravaganza isn't that easy here in Mauritius for exactly two reasons - either it is simply not available or it is expensive like nowhere. Well, by chance I came across an advert by a local hardware supplier and their offer of the week caught my attention - a portable USB monitor. Sounds cool, and the specs are okay as well. It's completely driven via USB 2.0, has a light weight, the dimensions would fit into my laptop bag and the resolution of 1366 x 768 pixels is okay for a second screen. Long story, short ending: I called them and only got to understand that they are out of stock - how convenient! Well, as usual I left some contact details and got the regular 'We call you back' answer. Surprisingly, I didn't receive a phone call as promised and after starting to complain via social media networks they finally came back to me with new units available - and *drum-roll* still the same price tag as promoted (and free delivery on top as one of their employees lives in Flic en Flac). Guess, it was a no-brainer to get at least one unit to fool around with. In worst case it might end up as image frame on the shelf or so... The usual suspects... Ubuntu first! Of course, the packing mentions only Windows or Mac OS as supported operating systems and without hesitation at all, I hooked up the device on my main machine running on Ubuntu 13.04. Result: Blackout... Hm, actually not the situation I was looking for but okay can't be too difficult to get this piece of hardware up and running. Following the output of syslogd (or dmesg if you prefer) the device has been recognised successfully but we got stuck in the initialisation phase. Oct 12 08:17:23 iospc2 kernel: [69818.689137] usb 2-4: new high-speed USB device number 5 using ehci-pciOct 12 08:17:23 iospc2 kernel: [69818.800306] usb 2-4: device descriptor read/64, error -32Oct 12 08:17:24 iospc2 kernel: [69819.043620] usb 2-4: New USB device found, idVendor=17e9, idProduct=4107Oct 12 08:17:24 iospc2 kernel: [69819.043630] usb 2-4: New USB device strings: Mfr=1, Product=2, SerialNumber=3Oct 12 08:17:24 iospc2 kernel: [69819.043636] usb 2-4: Product: e1649FwuOct 12 08:17:24 iospc2 kernel: [69819.043642] usb 2-4: Manufacturer: DisplayLinkOct 12 08:17:24 iospc2 kernel: [69819.043647] usb 2-4: SerialNumber: FJBD7HA000778Oct 12 08:17:24 iospc2 kernel: [69819.046073] hid-generic 0003:17E9:4107.0008: hiddev0,hidraw5: USB HID v1.10 Device [DisplayLink e1649Fwu] on usb-0000:00:1d.7-4/input1Oct 12 08:17:24 iospc2 mtp-probe: checking bus 2, device 5: "/sys/devices/pci0000:00/0000:00:1d.7/usb2/2-4"Oct 12 08:17:24 iospc2 mtp-probe: bus: 2, device: 5 was not an MTP deviceOct 12 08:17:30 iospc2 kernel: [69825.411220] [drm] vendor descriptor length:17 data:17 5f 01 00 15 05 00 01 03 00 04Oct 12 08:17:30 iospc2 kernel: [69825.498778] udl 2-4:1.0: fb1: udldrmfb frame buffer deviceOct 12 08:17:30 iospc2 kernel: [69825.498786] [drm] Initialized udl 0.0.1 20120220 on minor 1Oct 12 08:17:30 iospc2 kernel: [69825.498909] usbcore: registered new interface driver udl The device has been recognised as USB device without any question and it is listed properly: # lsusb...Bus 002 Device 005: ID 17e9:4107 DisplayLink ... A quick and dirty research on the net gave me some hints towards the udlfb framebuffer device for USB DisplayLink devices. By default this kernel module is blacklisted $ less /etc/modprobe.d/blacklist-framebuffer.conf | grep udl#blacklist udlblacklist udlfb and it is recommended to load it manually. So, unloading the whole udl stack and giving udlfb a shot: Oct 12 08:22:31 iospc2 kernel: [70126.642809] usbcore: registered new interface driver udlfb But still no reaction on the external display which supposedly should have been on and green. Display okay? Test run on Windows Just to be on the safe side and to exclude any hardware related defects or whatsoever - you never know what happened during delivery. I moved the display to a new position on the opposite side of my laptop, installed the display drivers first in Windows Vista (I know, I know...) as recommended in the manual, and then finally hooked it up on that machine. Tada! Display has been recognised correctly and I have a proper choice between cloning and extending my desktop. Testing whether the display is working properly - using Windows Vista Okay, good to know that there is nothing wrong on the hardware side just software... Back to Ubuntu - Kernel too old Some more research on Google and various hits recommend that the original displaylink driver has been merged into the recent kernel development and one should manually upgrade the kernel image (and both header) packages for Ubuntu. At least kernel 3.9 or higher would be necessary, and so I went out to this URL: http://kernel.ubuntu.com/~kernel-ppa/mainline/ and I downloaded all the good stuff from the v3.9-raring directory. The installation itself is easy going via dpkg: $ sudo dpkg -i linux-image-3.9.0-030900-generic_3.9.0-030900.201304291257_amd64.deb$ sudo dpkg -i linux-headers-3.9.0-030900_3.9.0-030900.201304291257_all.deb$ sudo dpkg -i linux-headers-3.9.0-030900-generic_3.9.0-030900.201304291257_amd64.deb As with any kernel upgrades it is necessary to restart the system in order to use the new one. Said and done: $ uname -r3.9.0-030900-generic And now connecting the external display gives me the following output in /var/log/syslog: Oct 12 17:51:36 iospc2 kernel: [ 2314.984293] usb 2-4: new high-speed USB device number 6 using ehci-pciOct 12 17:51:36 iospc2 kernel: [ 2315.096257] usb 2-4: device descriptor read/64, error -32Oct 12 17:51:36 iospc2 kernel: [ 2315.337105] usb 2-4: New USB device found, idVendor=17e9, idProduct=4107Oct 12 17:51:36 iospc2 kernel: [ 2315.337115] usb 2-4: New USB device strings: Mfr=1, Product=2, SerialNumber=3Oct 12 17:51:36 iospc2 kernel: [ 2315.337122] usb 2-4: Product: e1649FwuOct 12 17:51:36 iospc2 kernel: [ 2315.337127] usb 2-4: Manufacturer: DisplayLinkOct 12 17:51:36 iospc2 kernel: [ 2315.337132] usb 2-4: SerialNumber: FJBD7HA000778Oct 12 17:51:36 iospc2 kernel: [ 2315.338292] udlfb: DisplayLink e1649Fwu - serial #FJBD7HA000778Oct 12 17:51:36 iospc2 kernel: [ 2315.338299] udlfb: vid_17e9&pid_4107&rev_0129 driver's dlfb_data struct at ffff880117e59000Oct 12 17:51:36 iospc2 kernel: [ 2315.338303] udlfb: console enable=1Oct 12 17:51:36 iospc2 kernel: [ 2315.338306] udlfb: fb_defio enable=1Oct 12 17:51:36 iospc2 kernel: [ 2315.338309] udlfb: shadow enable=1Oct 12 17:51:36 iospc2 kernel: [ 2315.338468] udlfb: vendor descriptor length:17 data:17 5f 01 0015 05 00 01 03 00 04Oct 12 17:51:36 iospc2 kernel: [ 2315.338473] udlfb: DL chip limited to 1500000 pixel modesOct 12 17:51:36 iospc2 kernel: [ 2315.338565] udlfb: allocated 4 65024 byte urbsOct 12 17:51:36 iospc2 kernel: [ 2315.343592] hid-generic 0003:17E9:4107.0009: hiddev0,hidraw5: USB HID v1.10 Device [DisplayLink e1649Fwu] on usb-0000:00:1d.7-4/input1Oct 12 17:51:36 iospc2 mtp-probe: checking bus 2, device 6: "/sys/devices/pci0000:00/0000:00:1d.7/usb2/2-4"Oct 12 17:51:36 iospc2 mtp-probe: bus: 2, device: 6 was not an MTP deviceOct 12 17:51:36 iospc2 kernel: [ 2315.426583] udlfb: 1366x768 @ 59 Hz valid modeOct 12 17:51:36 iospc2 kernel: [ 2315.426589] udlfb: Reallocating framebuffer. Addresses will change!Oct 12 17:51:36 iospc2 kernel: [ 2315.428338] udlfb: 1366x768 @ 59 Hz valid modeOct 12 17:51:36 iospc2 kernel: [ 2315.428343] udlfb: set_par mode 1366x768Oct 12 17:51:36 iospc2 kernel: [ 2315.430620] udlfb: DisplayLink USB device /dev/fb1 attached. 1366x768 resolution. Using 4104K framebuffer memory Okay, that's looks more promising but still only blackout on the external screen... And yes, due to my previous modifications I swapped the blacklisted kernel modules: $ less /etc/modprobe.d/blacklist-framebuffer.conf | grep udlblacklist udl#blacklist udlfb Silly me! Okay, back to the original situation in which udl is allowed and udlfb blacklisted. Now, the logging looks similar to this and the screen shows those maroon-brown and azure-blue horizontal bars as described on other online resources. Oct 15 21:27:23 iospc2 kernel: [80934.308238] usb 2-4: new high-speed USB device number 5 using ehci-pciOct 15 21:27:23 iospc2 kernel: [80934.420244] usb 2-4: device descriptor read/64, error -32Oct 15 21:27:24 iospc2 kernel: [80934.660822] usb 2-4: New USB device found, idVendor=17e9, idProduct=4107Oct 15 21:27:24 iospc2 kernel: [80934.660832] usb 2-4: New USB device strings: Mfr=1, Product=2, SerialNumber=3Oct 15 21:27:24 iospc2 kernel: [80934.660838] usb 2-4: Product: e1649FwuOct 15 21:27:24 iospc2 kernel: [80934.660844] usb 2-4: Manufacturer: DisplayLinkOct 15 21:27:24 iospc2 kernel: [80934.660850] usb 2-4: SerialNumber: FJBD7HA000778Oct 15 21:27:24 iospc2 kernel: [80934.663391] hid-generic 0003:17E9:4107.0008: hiddev0,hidraw5: USB HID v1.10 Device [DisplayLink e1649Fwu] on usb-0000:00:1d.7-4/input1Oct 15 21:27:24 iospc2 mtp-probe: checking bus 2, device 5: "/sys/devices/pci0000:00/0000:00:1d.7/usb2/2-4"Oct 15 21:27:24 iospc2 mtp-probe: bus: 2, device: 5 was not an MTP deviceOct 15 21:27:25 iospc2 kernel: [80935.742407] [drm] vendor descriptor length:17 data:17 5f 01 00 15 05 00 01 03 00 04Oct 15 21:27:25 iospc2 kernel: [80935.834403] udl 2-4:1.0: fb1: udldrmfb frame buffer deviceOct 15 21:27:25 iospc2 kernel: [80935.834416] [drm] Initialized udl 0.0.1 20120220 on minor 1Oct 15 21:27:25 iospc2 kernel: [80935.836389] usbcore: registered new interface driver udlOct 15 21:27:25 iospc2 kernel: [80936.021458] [drm] write mode info 153 Next, it's time to enable the display for our needs... This can be done either via UI or console, just as you'd prefer it. Adding the external USB display under Linux isn't an issue after all... Settings Manager => Display Personally, I like the console. With the help of xrandr we get the screen identifier first $ xrandrScreen 0: minimum 320 x 200, current 3200 x 1080, maximum 32767 x 32767LVDS1 connected 1280x800+0+0 (normal left inverted right x axis y axis) 331mm x 207mm...DVI-0 connected 1366x768+0+0 (normal left inverted right x axis y axis) 344mm x 193mm   1366x768       60.0*+ and then give it the usual shot with auto-configuration. Let the system decide what's best for your hardware... $ xrandr --output DVI-0 --off$ xrandr --output DVI-0 --auto And there we go... Cloned output of main display: New kernel, new display... The external USB display works out-of-the-box with a Linux kernel > 3.9.0. Despite of a good number of resources it is absolutely not necessary to create a Device or Screen section in one of Xorg.conf files. This information belongs to the past and is not valid on kernel 3.9 or higher. Same hardware but Windows 8 Of course, I wanted to know how the latest incarnation from Redmond would handle the new hardware... Flawless! Most interesting aspect here: I did not use the driver installation medium on purpose. And I was right... not too long afterwards a dialog with the EULA of DisplayLink appeared on the main screen. And after confirmation of same it took some more seconds and the external USB monitor was ready to rumble. Well, and not only that one... but see for yourself. This time Windows 8 was the easiest solution after all. Resume I can highly recommend this type of hardware to anyone asking me. Although, it's dimensions are 15.6" it is actually lighter than my Samsung Galaxy Tab 10.1 and it still fits into my laptop bag without any issues. From now on... no more single screen while developing software on the road!

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• Clusterware 11gR2 &ndash; Setting up an Active/Passive failover configuration

  - by Gilles Haro

  Oracle is providing a large range of interesting solutions to ensure High Availability of the database. Dataguard, RAC or even both configurations (as recommended by Oracle for a Maximum Available Architecture - MAA) are the most frequently found and used solutions. But, when it comes to protecting a system with an Active/Passive architecture with failover capabilities, people often thinks to other expensive third party cluster systems. Oracle Clusterware technology, which comes along at no extra-cost with Oracle Database or Oracle Unbreakable Linux, is - in the knowing of most people - often linked to Oracle RAC and therefore, is seldom used to implement failover solutions. Oracle Clusterware 11gR2  (a part of Oracle 11gR2 Grid Infrastructure)  provides a comprehensive framework to setup automatic failover configurations. It is actually possible to make "failover-able'", and then to protect, almost any kind of application (from the simple xclock to the most complex Application Server). Quoting Oracle: “Oracle Clusterware is a portable cluster software that allows clustering of single servers so that they cooperate as a single system. Oracle Clusterware also provides the required infrastructure for Oracle Real Application Clusters (RAC). In addition Oracle Clusterware enables the protection of any Oracle application or any other kind of application within a cluster.” In the next couple of lines, I will try to present the different steps to achieve this goal : Have a fully operational 11gR2 database protected by automatic failover capabilities. I assume you are fluent in installing Oracle Database 11gR2, Oracle Grid Infrastructure 11gR2 on a Linux system and that ASM is not a problem for you (as I am using it as a shared storage). If not, please have a look at Oracle Documentation. As often, I made my tests using an Oracle VirtualBox environment. The scripts are tested and functional on my system. Unfortunately, there can always be a typo or a mistake. This blog entry does not replace a course around the Clusterware Framework. I just hope it will let you see how powerful it is and that it will give you the whilst to go further with it...  Note : This entry has been revised (rev.2) following comments from Philip Newlan. Prerequisite 2 Linux boxes (OELCluster01 and OELCluster02) at the same OS level. I used OEL 5 Update 5 with an Enterprise Kernel. Shared Storage (SAN). On my VirtualBox system, I used Openfiler to simulate the SAN Oracle 11gR2 Database (11.2.0.1) Oracle 11gR2 Grid Infrastructure (11.2.0.1)   Step 1 - Install the software Using asmlib, create 3 ASM disks (ASM_CRS, ASM_DTA and ASM_FRA) Install Grid Infrastructure for a cluster (OELCluster01 and OELCluster02 are the 2 nodes of the cluster) Use ASM_CRS to store Voting Disk and OCR. Use SCAN. Install Oracle Database Standalone binaries on both nodes. Use asmca to check/mount the disk groups on 2 nodes Use dbca to create and configure a database on the primary node Let's name it DB11G. Copy the pfile, password file to the second node. Create adump directoty on the second node.   Step 2 - Setup the resource to be protected After its creation with dbca, the database is automatically protected by the Oracle Restart technology available with Grid Infrastructure. Consequently, it restarts automatically (if possible) after a crash (ex: kill -9 smon). A database resource has been created for that in the Cluster Registry. We can observe this with the command : crsctl status resource that shows and ora.dba11g.db entry. Let's save the definition of this resource, for future use : mkdir -p /crs/11.2.0/HA_scripts chown oracle:oinstall /crs/11.2.0/HA_scripts crsctl status resource ora.db11g.db -p > /crs/11.2.0/HA_scripts/myResource.txt Although very interesting, Oracle Restart is not cluster aware and cannot restart the database on any other node of the cluster. So, let's remove it from the OCR definitions, we don't need it ! srvctl stop database -d DB11G srvctl remove database -d DB11G Instead of it, we need to create a new resource of a more general type : cluster_resource. Here are the steps to achieve this : Create an action script :  /crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh #!/bin/bash export ORACLE_HOME=/oracle/product/11.2.0/dbhome_1 export ORACLE_SID=DB11G case $1 in 'start')   $ORACLE_HOME/bin/sqlplus /nolog <<EOF   connect / as sysdba   startup EOF   RET=0   ;; 'stop')   $ORACLE_HOME/bin/sqlplus /nolog <<EOF   connect / as sysdba   shutdown immediate EOF   RET=0   ;; 'clean')   $ORACLE_HOME/bin/sqlplus /nolog <<EOF   connect / as sysdba   shutdown abort    ##for i in `ps -ef | grep -i $ORACLE_SID | awk '{print $2}' ` ;do kill -9 $i; done EOF   RET=0   ;; 'check')    ok=`ps -ef | grep smon | grep $ORACLE_SID | wc -l`    if [ $ok = 0 ]; then      RET=1    else      RET=0    fi    ;; '*')      RET=0   ;; esac if [ $RET -eq 0 ]; then    exit 0 else    exit 1 fi   This script must provide, at least, methods to start, stop, clean and check the database. It is self-explaining and contains nothing special. Just be aware that it must be runnable (+x), it runs as Oracle user (because of the ACL property - see later) and needs to know about the environment. Also make sure it exists on every node of the cluster. Moreover, as of 11.2, the clean method is mandatory. It must provide the “last gasp clean up”, for example, a shutdown abort or a kill –9 of all the remaining processes. chmod +x /crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh scp  /crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh   oracle@OELCluster02:/crs/11.2.0/HA_scripts Create a new resource file, based on the information we got from previous  myResource.txt . Name it myNewResource.txt. myResource.txt  is shown below. As we can see, it defines an ora.database.type resource, named ora.db11g.db. A lot of properties are related to this type of resource and do not need to be used for a cluster_resource. NAME=ora.db11g.db TYPE=ora.database.type ACL=owner:oracle:rwx,pgrp:oinstall:rwx,other::r-- ACTION_FAILURE_TEMPLATE= ACTION_SCRIPT= ACTIVE_PLACEMENT=1 AGENT_FILENAME=%CRS_HOME%/bin/oraagent%CRS_EXE_SUFFIX% AUTO_START=restore CARDINALITY=1 CHECK_INTERVAL=1 CHECK_TIMEOUT=600 CLUSTER_DATABASE=false DB_UNIQUE_NAME=DB11G DEFAULT_TEMPLATE=PROPERTY(RESOURCE_CLASS=database) PROPERTY(DB_UNIQUE_NAME= CONCAT(PARSE(%NAME%, ., 2), %USR_ORA_DOMAIN%, .)) ELEMENT(INSTANCE_NAME= %GEN_USR_ORA_INST_NAME%) DEGREE=1 DESCRIPTION=Oracle Database resource ENABLED=1 FAILOVER_DELAY=0 FAILURE_INTERVAL=60 FAILURE_THRESHOLD=1 GEN_AUDIT_FILE_DEST=/oracle/admin/DB11G/adump GEN_USR_ORA_INST_NAME= GEN_USR_ORA_INST_NAME@SERVERNAME(oelcluster01)=DB11G HOSTING_MEMBERS= INSTANCE_FAILOVER=0 LOAD=1 LOGGING_LEVEL=1 MANAGEMENT_POLICY=AUTOMATIC NLS_LANG= NOT_RESTARTING_TEMPLATE= OFFLINE_CHECK_INTERVAL=0 ORACLE_HOME=/oracle/product/11.2.0/dbhome_1 PLACEMENT=restricted PROFILE_CHANGE_TEMPLATE= RESTART_ATTEMPTS=2 ROLE=PRIMARY SCRIPT_TIMEOUT=60 SERVER_POOLS=ora.DB11G SPFILE=+DTA/DB11G/spfileDB11G.ora START_DEPENDENCIES=hard(ora.DTA.dg,ora.FRA.dg) weak(type:ora.listener.type,uniform:ora.ons,uniform:ora.eons) pullup(ora.DTA.dg,ora.FRA.dg) START_TIMEOUT=600 STATE_CHANGE_TEMPLATE= STOP_DEPENDENCIES=hard(intermediate:ora.asm,shutdown:ora.DTA.dg,shutdown:ora.FRA.dg) STOP_TIMEOUT=600 UPTIME_THRESHOLD=1h USR_ORA_DB_NAME=DB11G USR_ORA_DOMAIN=haroland USR_ORA_ENV= USR_ORA_FLAGS= USR_ORA_INST_NAME=DB11G USR_ORA_OPEN_MODE=open USR_ORA_OPI=false USR_ORA_STOP_MODE=immediate VERSION=11.2.0.1.0 I removed database type related entries from myResource.txt and modified some other to produce the following myNewResource.txt. Notice the NAME property that should not have the ora. prefix Notice the TYPE property that is not ora.database.type but cluster_resource. Notice the definition of ACTION_SCRIPT. Notice the HOSTING_MEMBERS that enumerates the members of the cluster (as returned by the olsnodes command). NAME=DB11G.db TYPE=cluster_resource DESCRIPTION=Oracle Database resource ACL=owner:oracle:rwx,pgrp:oinstall:rwx,other::r-- ACTION_SCRIPT=/crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh PLACEMENT=restricted ACTIVE_PLACEMENT=0 AUTO_START=restore CARDINALITY=1 CHECK_INTERVAL=10 DEGREE=1 ENABLED=1 HOSTING_MEMBERS=oelcluster01 oelcluster02 LOGGING_LEVEL=1 RESTART_ATTEMPTS=1 START_DEPENDENCIES=hard(ora.DTA.dg,ora.FRA.dg) weak(type:ora.listener.type,uniform:ora.ons,uniform:ora.eons) pullup(ora.DTA.dg,ora.FRA.dg) START_TIMEOUT=600 STOP_DEPENDENCIES=hard(intermediate:ora.asm,shutdown:ora.DTA.dg,shutdown:ora.FRA.dg) STOP_TIMEOUT=600 UPTIME_THRESHOLD=1h Register the resource. Take care of the resource type. It needs to be a cluster_resource and not a ora.database.type resource (Oracle recommendation) .   crsctl add resource DB11G.db  -type cluster_resource -file /crs/11.2.0/HA_scripts/myNewResource.txt Step 3 - Start the resource crsctl start resource DB11G.db This command launches the ACTION_SCRIPT with a start and a check parameter on the primary node of the cluster. Step 4 - Test this We will test the setup using 2 methods. crsctl relocate resource DB11G.db This command calls the ACTION_SCRIPT  (on the two nodes)  to stop the database on the active node and start it on the other node. Once done, we can revert back to the original node, but, this time we can use a more "MS$ like" method :Turn off the server on which the database is running. After short delay, you should observe that the database is relocated on node 1. Conclusion Once the software installed and the standalone database created (which is a rather common and usual task), the steps to reach the objective are quite easy : Create an executable action script on every node of the cluster. Create a resource file. Create/Register the resource with OCR using the resource file. Start the resource. This solution is a very interesting alternative to licensable third party solutions. References Clusterware 11gR2 documentation Oracle Clusterware Resource Reference Clusterware for Unbreakable Linux Using Oracle Clusterware to Protect A Single Instance Oracle Database 11gR1 (to have an idea of complexity) Oracle Clusterware on OTN   Gilles Haro Technical Expert - Core Technology, Oracle Consulting   

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• Different Flavors of Leases Back On

  - by Theresa Hickman

  Given the continued interest regarding the proposed changes to Lease Accounting, I decided to write another entry on this controversial topic with colorful commentary from our resident accounting expert, Seamus Moran. Background (A History Lesson) Back in 1976, the FASB issued FAS 13, “Accounting for Leases” that permitted leases to be either an operating lease or capital (finance) lease. In substance, operating leases are a form of off-balance sheet financing. According to Seamus, operating leases date back to the launch of the Boeing 707 in the 1950s.  Because the aircraft was so much more expensive than previous aircrafts, the industry came up with the operating lease concept to accommodate these jet liners that dominated air transport.  How it worked was the bank would buy the plane and lease it to the airline.  Because the bank never controlled or flew the plane, they never placed the asset on their balance sheet, and because the airline never owned the plane, they didn’t place it on their balance sheet either. They simply treated the monthly lease payments as rental expenses on the P&L.   August 2010 Original Lease Accounting Changes In August 2010, FASB and IASB decided to overhaul lease accounting as part of their joint commitment “to insure that investors and other users of financial statements are provided useful, transparent, and complete information about leasing transactions in the financial statements.”  Some say that the current lease accounting standards are broken because it keeps assets off the balance sheet, hidden from investors’ view. The original proposal abolished operating leases and only permitted capital leases where all leases would be recorded on the balance sheet as assets and liabilities. The asset side would reflect the right to use the asset for the leased term, and the liability side would reflect the obligation to make lease payments.   Why Companies Were Freaking Out According to the SEC, the financial impact of the aforementioned lease changes was estimated to add more than $1.3 trillion of operating lease obligations to corporate balance sheets. Many companies in various industries, especially retail, are concerned because the changes are significant and will impact existing leases with no grandfather clause for existing operating leases. Of course, the banks and airlines I mentioned earlier really hate this because neither wants to report the airplane (now costing around $60 M) as an asset. Regular companies were concerned that they would have to report routine short term leases of real estate or equipment as fixed assets, even though they were really just longer term rentals.  One company we spoke to leased roadside billboards, and really did not consider them to be fixed assets in any way. Obviously, these changes would have had a profound and lasting effect on a company’s financial and real estate strategies and significantly impact its financial statements.  Financial statements would show higher depreciation and interest expense with significantly higher total assets and debt. In terms of financial metrics, they’re negatively impacted. It would raise a company’s debt-to-capital ratio to reflect the higher debt compared to equity, it would negatively impact their return-on-assets because now companies will appear more asset intensive, and it will decrease EPS, lowering shareholder ROI. Feb. 2011 Recent Update The comment period on leases closed in December 2010. The FASB and the IASB have met several times since then and published their initial responses to the input they received from the various interested parties.  They are “redeliberating” the principles involved in Lease Accounting.  Some of the issues they are looking at include: The core definition of a lease.  This will articulate principles on what is a lease and what is “not-a-lease.” One theory or supposition is that they might define a lease as the transfer of certain but not all major ownership attributes for a certain period of time.  So a year’s lease of an aircraft might be a “lease,” but a year’s lease of half a floor in an office building would be “not-a-lease.”  The ownership attributes transferred from the core owner to the user are different; the airline must maintain, paint, and do whatever it needs to do on the aircraft. However, the office renter will have strictly limited rights in respect to the rented space. The differences between a lease contract and service contract.  Even if they call them “leases” for the purpose of commercial law, a service contract might not be accounted for as a lease. The accounting to be done by the lessee.  They would define when the bank or landlord would retain the asset on their balance sheet, and perhaps by implication, when the lessor would not need to include the asset on theirs.  So if the finance house keeps the airplane or office on their balance sheet, the tenant doesn’t need to.  I’m not sure that I can draw the opposite conclusion where the finance house doesn’t report but the tenant must. The difference, if any, between a financing lease and other leases, and the implications to the accounting. The present value calculation when renewable terms exist. They have reduced the circumstances in which one must look at the renewable terms of a lease in calculating the present value.  In most circumstances, you will use the lease term rather than the potential renewable term. Their latest discussion this past week with the contents of the discussion was not available at the time of me writing this entry.  For more details, the results of the discussions are posted on both the FASB and the IASB websites. Implied Software Changes Whatever the final rules turn out to be, all ERP systems, such as Oracle E-Business Suite, PeopleSoft Enterprise, JD Edwards, and Oracle Hyperion will need to change their software to accommodate the new rules. The following lists some changes that might have to be made to accounting software depending on what the final standards will be in June 2011: Lease tracking may require modifications with tracking of additional lease details that might require a centralized repository to maintain Accounting may need to be modified as there are many changes to how capital leases and the new “other than finance” leases are accounted for both on the lessee and lessor side.  For example, valuation, amortization, and disclosure will be considerably different requiring different types of data to be captured. Companies may need to modify their chart of accounts depending on how they want to track leases, which could then impact financial reporting and consolidation Business processes may require changes which could then impact internal controls Software applications may need to perform more advanced computations on leases Reports and KPIs may need to reflect new operating metrics Hold Onto Your Seats           Before you redo all your lease agreements and call your software vendors asking when the changes to the software will be made, remember that the rules are not finalized yet, and from appearances, will not reflect the proposals in the exposure draft.  Not only are there objections to putting the operating lease assets on anyone’s balance sheet, there are lots of objections to subjectivity and the data required for the valuation.  According to Seamus, there is huge opposition from New York bankers, the airlines, the EU, the Communist Party of China (since it impacts their exporting business), and Republicans (hearing complaints from small and large businesses). Even if everyone can agree on the proposed changes, 2013 might be the earliest that companies would need to change how they report leases. The Boards will finish their deliberations in April, May or June 2011.  As we’ve seen with other Exposure Drafts, if the changes are minor and the principles met the General Acceptance consensus criteria, the Standard could be finalized at that time.  However, if substantial changes are made, a fresh exposure draft, comment period, and review period might be involved, too. Seamus added an interesting perspective. Even if the proposed changes do pass, don’t you think our customers, such as Boeing, GE Capital, United Airlines, etc. will be clever enough to come up with a new kind of financing arrangement that complies with the new accounting? How about the large retail customers, such as Best Buy and Macerich? Don’t you think they might simply cut deals around retail locations with new contracts that prevent their leases from being capital leases? Instead of blindly adapting the software to meet the principles outlined in the final standard, our software needs to accommodate how businesses will respond to the new rules. We cannot know our customers’ responses until the rules are finalized. Oracle is aware of the potential changes and is staying abreast of the developments through our domain expertise staff, our relationship with customers, our market awareness, and, of course, our relationships with the Big 4. This is part of our normal process with respect to worldwide regulatory compliance. Oracle products have been IFRS and GAAP compliant for years and we will continue to maintain those standards going forward.

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• Clusterware 11gR2 &ndash; Setting up an Active/Passive failover configuration

  - by Gilles Haro

  Oracle provides many interesting ways to ensure High Availability. Dataguard configurations, RAC configurations or even both (as recommended for a Maximum Available Architecture - MAA) are the most frequently found. But when it comes to protecting a system with an Active/Passive architecture with failover capabilities, one often thinks to expensive third party cluster systems. Oracle Clusterware technology, which comes free with Oracle Database, is – in the knowing of most people - often linked to Oracle RAC and therefore, is rarely used to implement failover solutions. 11gR2 Clusterware – which is part of Oracle Grid Infrastructure - provides a comprehensive framework to setup automatic failover configurations. It is actually possible to make “failover-able'” and, therefore to protect, almost every kind of application (from xclock to the more complex Application Server) In the next couple of lines, I will try to present the different steps to achieve this goal : Have a fully operational 11gR2 database protected by automatic failover capabilities. I assume you are fluent in installing Oracle Database 11gR2, Oracle Grid Infrastructure 11gR2 on a Linux system and that ASM is not a problem for you (as I am using it as a shared storage). If not, please have a look at Oracle Documentation. As often, I made my tests using an Oracle VirtualBox environment. The scripts are tested and functional. Unfortunately, there can always be a typo or a mistake. This blog entry is not a course around the Clusterware Framework. I just hope it will let you see how powerful it is and that it will give you the whilst to go further with it…   Prerequisite 2 Linux boxes (OELCluster01 and OELCluster02) at the same OS level. I used OEL 5 Update 5 with Enterprise Kernel. Shared Storage (SAN). On my VirtualBox system, I used Openfiler to simulate the SAN Oracle 11gR2 Database (11.2.0.1) Oracle 11gR2 Grid Infrastructure (11.2.0.1)   Step 1 – Install the software Using asmlib, create 3 ASM disks (ASM_CRS, ASM_DTA and ASM_FRA) Install Grid Infrastructure for a cluster (OELCluster01 and OELCluster02 are the 2 nodes of the cluster) Use ASM_CRS to store Voting Disk and OCR. Use SCAN. Install Oracle Database Standalone binaries on both nodes. Use asmca to check/mount the disk groups on 2 nodes Use dbca to create and configure a database on the primary node Let’s name it DB11G. Copy the pfile, password file to the second node. Create adump directoty on the second node.   Step 2 - Setup the resource to be protected After its creation with dbca, the database is automatically protected by the Oracle Restart technology available with Grid Infrastructure. Consequently, it restarts automatically (if possible) after a crash (ex: kill –9 smon). A database resource has been created for that in the Cluster Registry. We can observe this with the command : crsctl status resource that shows and ora.dba11g.db entry. Let’s save the definition of this resource, for future use : mkdir –p /crs/11.2.0/HA_scripts chown oracle:oinstall /crs/11.2.0/HA_scripts crsctl status resource ora.db11g.db -p > /crs/11.2.0/HA_scripts/myResource.txt Although very interesting, Oracle Restart is not cluster aware and cannot restart the database on any other node of the cluster. So, let’s remove it from the OCR definitions, we don’t need it ! srvctl stop database -d DB11G srvctl remove database -d DB11G Instead of it, we need to create a new resource of a more general type : cluster_resource. Here are the steps to achieve this : Create an action script :  /crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh #!/bin/bash export ORACLE_HOME=/oracle/product/11.2.0/dbhome_1 export ORACLE_SID=DB11G case $1 in 'start')   $ORACLE_HOME/bin/sqlplus /nolog <<EOF   connect / as sysdba   startup EOF   RET=0   ;; 'stop')   $ORACLE_HOME/bin/sqlplus /nolog <<EOF   connect / as sysdba   shutdown immediate EOF   RET=0   ;; 'check')    ok=`ps -ef | grep smon | grep $ORACLE_SID | wc -l`    if [ $ok = 0 ]; then      RET=1    else      RET=0    fi    ;; '*')      RET=0   ;; esac if [ $RET -eq 0 ]; then    exit 0 else    exit 1 fi   This script must provide, at least, methods to start, stop and check the database. It is self-explaining and contains nothing special. Just be aware that it is run as Oracle user (because of the ACL property – see later) and needs to know about the environment. It also needs to be present on every node of the cluster. chmod +x /crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh scp  /crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh   oracle@OELCluster02:/crs/11.2.0/HA_scripts Create a new resource file, based on the information we got from previous  myResource.txt . Name it myNewResource.txt. myResource.txt  is shown below. As we can see, it defines an ora.database.type resource, named ora.db11g.db. A lot of properties are related to this type of resource and do not need to be used for a cluster_resource. NAME=ora.db11g.db TYPE=ora.database.type ACL=owner:oracle:rwx,pgrp:oinstall:rwx,other::r-- ACTION_FAILURE_TEMPLATE= ACTION_SCRIPT= ACTIVE_PLACEMENT=1 AGENT_FILENAME=%CRS_HOME%/bin/oraagent%CRS_EXE_SUFFIX% AUTO_START=restore CARDINALITY=1 CHECK_INTERVAL=1 CHECK_TIMEOUT=600 CLUSTER_DATABASE=false DB_UNIQUE_NAME=DB11G DEFAULT_TEMPLATE=PROPERTY(RESOURCE_CLASS=database) PROPERTY(DB_UNIQUE_NAME= CONCAT(PARSE(%NAME%, ., 2), %USR_ORA_DOMAIN%, .)) ELEMENT(INSTANCE_NAME= %GEN_USR_ORA_INST_NAME%) DEGREE=1 DESCRIPTION=Oracle Database resource ENABLED=1 FAILOVER_DELAY=0 FAILURE_INTERVAL=60 FAILURE_THRESHOLD=1 GEN_AUDIT_FILE_DEST=/oracle/admin/DB11G/adump GEN_USR_ORA_INST_NAME= GEN_USR_ORA_INST_NAME@SERVERNAME(oelcluster01)=DB11G HOSTING_MEMBERS= INSTANCE_FAILOVER=0 LOAD=1 LOGGING_LEVEL=1 MANAGEMENT_POLICY=AUTOMATIC NLS_LANG= NOT_RESTARTING_TEMPLATE= OFFLINE_CHECK_INTERVAL=0 ORACLE_HOME=/oracle/product/11.2.0/dbhome_1 PLACEMENT=restricted PROFILE_CHANGE_TEMPLATE= RESTART_ATTEMPTS=2 ROLE=PRIMARY SCRIPT_TIMEOUT=60 SERVER_POOLS=ora.DB11G SPFILE=+DTA/DB11G/spfileDB11G.ora START_DEPENDENCIES=hard(ora.DTA.dg,ora.FRA.dg) weak(type:ora.listener.type,uniform:ora.ons,uniform:ora.eons) pullup(ora.DTA.dg,ora.FRA.dg) START_TIMEOUT=600 STATE_CHANGE_TEMPLATE= STOP_DEPENDENCIES=hard(intermediate:ora.asm,shutdown:ora.DTA.dg,shutdown:ora.FRA.dg) STOP_TIMEOUT=600 UPTIME_THRESHOLD=1h USR_ORA_DB_NAME=DB11G USR_ORA_DOMAIN=haroland USR_ORA_ENV= USR_ORA_FLAGS= USR_ORA_INST_NAME=DB11G USR_ORA_OPEN_MODE=open USR_ORA_OPI=false USR_ORA_STOP_MODE=immediate VERSION=11.2.0.1.0 I removed database type related entries from myResource.txt and modified some other to produce the following myNewResource.txt. Notice the NAME property that should not have the ora. prefix Notice the TYPE property that is not ora.database.type but cluster_resource. Notice the definition of ACTION_SCRIPT. Notice the HOSTING_MEMBERS that enumerates the members of the cluster (as returned by the olsnodes command). NAME=DB11G.db TYPE=cluster_resource DESCRIPTION=Oracle Database resource ACL=owner:oracle:rwx,pgrp:oinstall:rwx,other::r-- ACTION_SCRIPT=/crs/11.2.0/HA_scripts/my_ActivePassive_Cluster.sh PLACEMENT=restricted ACTIVE_PLACEMENT=0 AUTO_START=restore CARDINALITY=1 CHECK_INTERVAL=10 DEGREE=1 ENABLED=1 HOSTING_MEMBERS=oelcluster01 oelcluster02 LOGGING_LEVEL=1 RESTART_ATTEMPTS=1 START_DEPENDENCIES=hard(ora.DTA.dg,ora.FRA.dg) weak(type:ora.listener.type,uniform:ora.ons,uniform:ora.eons) pullup(ora.DTA.dg,ora.FRA.dg) START_TIMEOUT=600 STOP_DEPENDENCIES=hard(intermediate:ora.asm,shutdown:ora.DTA.dg,shutdown:ora.FRA.dg) STOP_TIMEOUT=600 UPTIME_THRESHOLD=1h Register the resource. Take care of the resource type. It needs to be a cluster_resource and not a ora.database.type resource (Oracle recommendation) .   crsctl add resource DB11G.db  -type cluster_resource -file /crs/11.2.0/HA_scripts/myNewResource.txt Step 3 - Start the resource crsctl start resource DB11G.db This command launches the ACTION_SCRIPT with a start and a check parameter on the primary node of the cluster. Step 4 - Test this We will test the setup using 2 methods. crsctl relocate resource DB11G.db This command calls the ACTION_SCRIPT  (on the two nodes)  to stop the database on the active node and start it on the other node. Once done, we can revert back to the original node, but, this time we can use a more “MS$ like” method :Turn off the server on which the database is running. After short delay, you should observe that the database is relocated on node 1. Conclusion Once the software installed and the standalone database created (which is a rather common and usual task), the steps to reach the objective are quite easy : Create an executable action script on every node of the cluster. Create a resource file. Create/Register the resource with OCR using the resource file. Start the resource. This solution is a very interesting alternative to licensable third party solutions.   References Clusterware 11gR2 documentation Oracle Clusterware Resource Reference   Gilles Haro Technical Expert - Core Technology, Oracle Consulting   

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• Agile Testing Days 2012 – Day 2 – Learn through disagreement

  - by Chris George

  I think I was in the right place! During Day 1 I kept on reading tweets about Lean Coffee that has happened earlier that morning. It intrigued me and I figured in for a penny in for a pound, and set my alarm for 6:45am. Following the award night the night before, it was _really_ hard getting up when it went off, but I did and after a very early breakfast, set off for the 10 min walk to the Dorint. With Lean Coffee due to start at 07:30, I arrived at the hotel and made my way to one of the hotel bars. I soon realised I was in the right place as although the bar was empty, there was a table with post-it’s and pens! This MUST be the place! The premise of Lean Coffee is to have several small timeboxed discussions. Everyone writes down what they would like to discuss on post-its that are then briefly explained and submitted to the pile. Once everyone is done, the group dot-votes on the topics. The topics are then sorted by the dot vote counts and the discussions begin. Each discussion had 8 mins to start with, which meant it prevented the discussions getting off topic too much. After the time elapsed, the group had a vote whether to extend the discussion by a further 4 mins or move on. Several discussion were had around training, soft skills etc. The conversations were really interesting and there were quite a few good ideas. Overall it was a very enjoyable experience, certainly worth the early start! Make Melly Happy Following Lean Coffee was real coffee, and much needed that was! The first keynote of the day was “Let’s help Melly (Changing Work into Life)”by Jurgen Appelo. Draw lines to track happiness This was a very interesting presentation, and set the day nicely. The theme to the keynote was projects are about the people, more-so than the actual tasks. So he started by showing a photo of an employee ‘Melly’ who looked happy enough. He then stated that she looked happy but actually hated her job. In fact 50% of Americans hate their jobs. He went on to say that the world over 50% of people hate Americans their jobs. Jurgen talked about many ways to reduce the feedback cycle, not only of the project, but of the people management. Ideas such as Happiness doors, happiness tracking (drawing lines on a wall indicating your happiness for that day), kudo boxes (to compliment a colleague for good work). All of these (and more) ideas stimulate conversation amongst the team, lead to early detection of issues and investigation of solutions. I’ve massively simplified Jurgen’s keynote and have certainly not done it justice, so I will post a link to the video once it’s available. Following more coffee, the next talk was “How releasing faster changes testing” by Alexander Schwartz. This is a topic very close to our hearts at the moment, so I was eager to find out any juicy morsels that could help us achieve more frequent releases, and Alex did not disappoint. He started off by confirming something that I have been a firm believer in for a number of years now; adding more people can do more harm than good when trying to release. This is for a number of reasons, but just adding new people to a team at such a critical time can be more of a drain on resources than they add. The alternative is to have the whole team have shared responsibility for faster delivery. So the whole team is responsible for quality and testing. Obviously you will have the test engineers on the project who have the specialist skills, but there is no reason that the entire team cannot do exploratory testing on the product. This links nicely with the Developer Exploratory testing presented by Sigge on Day 1, and certainly something that my team are really striving towards. Focus on cycle time, so what can be done to reduce the time between dev cycles, release cycles. What’s stops a release, what delays a release? all good solid questions that can be answered. Alex suggested that perhaps the product doesn’t need to be fully tested. Doing less testing will reduce the cycle time therefore get the release out faster. He suggested a risk-based approach to planning what testing needs to happen. Reducing testing could have an impact on revenue if it causes harm to customers, so test the ‘right stuff’! Determine a set of tests that are ‘face saving’ or ‘smoke’ tests. These tests cover the core functionality of the product and aim to prevent major embarrassment if these areas were to fail! Amongst many other very good points, Alex suggested that a good approach would be to release after every new feature is added. So do a bit of work -> release, do some more work -> release. By releasing small increments of work, the impact on the customer of bugs being introduced is reduced. Red Pill, Blue Pill The second keynote of the day was “Adaptation and improvisation – but your weakness is not your technique” by Markus Gartner and proved to be another very good presentation. It started off quoting lines from the Matrix which relate to adapting, improvising, realisation and mastery. It has alot of nerds in the room smiling! Markus went on to explain how through deliberate practice ( and a lot of it!) you can achieve mastery, but then you never stop learning. Through methods such as code retreats, testing dojos, workshops you can continually improve and learn. The code retreat idea was one that interested me. It involved pairing to write an automated test for, say, 45 mins, they deleting all the code, finding a different partner and writing the same test again! This is another keynote where the video will speak louder than anything I can write here! Markus did elaborate on something that Lisa and Janet had touched on yesterday whilst busting the myth that “Testers Must Code”. Whilst it is true that to be a tester, you don’t need to code, it is becoming more common that there is this crossover happening where more testers are coding and more programmers are testing. Markus made a special distinction between programmers and developers as testers develop tests code so this helped to make that clear. “Extending Continuous Integration and TDD with Continuous Testing” by Jason Ayers was my next talk after lunch. We already do CI and a bit of TDD on my project team so I was interested to see what this continuous testing thing was all about and whether it would actually work for us. At the start of the presentation I was of the opinion that it just would not work for us because our tests are too slow, and that would be the case for many people. Jason started off by setting the scene and saying that those doing TDD spend between 10-15% of their time waiting for tests to run. This can be reduced by testing less often, reducing the test time but this then increases the risk of introduced bugs not being spotted quickly. Therefore, in comes Continuous Testing (CT). CT systems run your unit tests whenever you save some code and runs them in the background so you can continue working. This is a really nice idea, but to do this, your tests must be fast, independent and reliable. The latter two should be the case anyway, and the first is ideal, but hard! Jason makes several suggestions to make tests fast. Firstly keep the scope of the test small, secondly spin off any expensive tests into a suite which is run, perhaps, overnight or outside of the CT system at any rate. So this started to change my mind, perhaps we could re-engineer our tests, and continuously run the quick ones to give an element of coverage. This talk was very interesting and I’ve already tried a couple of the tools mentioned on our product (Mighty Moose and NCrunch). Sadly due to the way our solution is built, it currently doesn’t work, but we will look at whether we can make this work because this has the potential to be a mini-game-changer for us. Using the wrong data Gojko’s Hierarchy of Quality The final keynote of the day was “Reinventing software quality” by Gojko Adzic. He opened the talk with the statement “We’ve got quality wrong because we are using the wrong data”! Gojko then went on to explain that we should judge a bug by whether the customer cares about it, not by whether we think it’s important. Why spend time fixing issues that the customer just wouldn’t care about and releasing months later because of this? Surely it’s better to release now and get customer feedback? This was another reference to the idea of how it’s better to build the right thing wrong than the wrong thing right. Get feedback early to make sure you’re making the right thing. Gojko then showed something which was very analogous to Maslow’s heirachy of needs. Successful – does it contribute to the business? Useful – does it do what the user wants Usable – does it do what it’s supposed to without breaking Performant/Secure – is it secure/is the performance acceptable Deployable Functionally ok – can it be deployed without breaking? He then explained that User Stories should focus on change. In other words they should focus on the users needs, not the users process. Describe what the change will be, how that change will happen then measure it! Networking and Beer Following the day’s closing keynote, there were drinks and nibble for the ‘Networking’ evening. This was a great opportunity to talk to people. I find approaching strangers very uncomfortable but once again, when in Rome! Pete Walen and I had a long conversation about only fixing issues that the customer cares about versus fixing issues that make you proud of your software! Without saying much, and asking the right questions, Pete made me re-evaluate my thoughts on the matter. Clever, very clever!  Oh and he ‘bought’ me a beer! My Takeaway Triple from Day 2: release small and release often to minimize issues creeping in and get faster feedback from ‘the real world’ Focus on issues that the customers care about, not what we think is important It’s okay to disagree with someone, even if they are well respected agile testing gurus, that’s how discussion and learning happens!  

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• Technology to communicate with someone with expressive aphasia?

  - by rascher

  A family member had a stroke a few years back and now has expressive aphasia. She understands what is said to her, is cognitive of what is going on, but cannot express herself. She is able to respond to yes/no questions (do you want to go shopping? are you looking for your earrings?) She is not, however, able to read (English is not her native language and she hasn't read Hindi for decades.) I am the technologist in the family, and I intend to come up with something to help us communicate. The idea is to have some sort of picture book where she can point to what she wants. My first question: does some sort of assistive technology for people with expressive aphasia already exist? These can be hardware or software devices? If not, then such a software doesn't seem difficult to write. My initial thought is to have an interface with pictures - maybe separated by category (food, shopping) - where she can point to an individual picture to indicate what she needs. We could easily add more items with such a software, and we could have an interface where she (or we) could "flip pages". Which suggests that the best solution would use a touch screen rather than a mouse. It would be really difficult to train her to aim a mouse or find keys on a keyboard. We're thinking of maybe getting a tablet and writing some basic software. But tablets computers are expensive and fragile - I'm not sure if it would be able to stand spills or being knocked about in a nursing home. So my next question: what kind of tablet-like devices are out there which I can program on? I don't know anything about hardware, but if there is something then we could special-order it. What would be safe and durable for such a project? We could do something on an iPod or cell phone, but I feel like that interface would be too small. Finally, does anyone here have experience with this kind of assistive technology? Things I might not anticipate when designing such a system? edit I've added a (pretty hefty!) bounty. I'd kinda like to open this question up to any suggestions, comments, and experiences that people might have. This is a pretty real and important project, so while we will (are working on) a solution, any insights would be particularly helpful. Right now the plan is to mount a screen in her room. We'll either teach her to use a trackball or use a touch-screen panel, after seeing what she is able to use with a simple prototype. Then software akin to an old "hypercard" deck: ---------------------------------------------------------------- | -------------- -------------- | | | Clothes | | Food | ... | | -------------- -------------- | | | | Pic of item 1 Pic of item 2 Pic of item 3 | | | | | | | | | | Pic of item 4 Pic of item 5 Pic of item 6 | | | | | | | | | | <-Back Next-> | ---------------------------------------------------------------- commentcommentcomment!

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• The Return Of __FILE__ And __LINE__ In .NET 4.5

  - by Alois Kraus

  Good things are hard to kill. One of the most useful predefined compiler macros in C/C++ were __FILE__ and __LINE__ which do expand to the compilation units file name and line number where this value is encountered by the compiler. After 4.5 versions of .NET we are on par with C/C++ again. It is of course not a simple compiler expandable macro it is an attribute but it does serve exactly the same purpose. Now we do get CallerLineNumberAttribute  == __LINE__ CallerFilePathAttribute        == __FILE__ CallerMemberNameAttribute  == __FUNCTION__ (MSVC Extension)   The most important one is CallerMemberNameAttribute which is very useful to implement the INotifyPropertyChanged interface without the need to hard code the name of the property anymore. Now you can simply decorate your change method with the new CallerMemberName attribute and you get the property name as string directly inserted by the C# compiler at compile time.   public string UserName { get { return _userName; } set { _userName=value; RaisePropertyChanged(); // no more RaisePropertyChanged(“UserName”)! } } protected void RaisePropertyChanged([CallerMemberName] string member = "") { var copy = PropertyChanged; if(copy != null) { copy(new PropertyChangedEventArgs(this, member)); } } Nice and handy. This was obviously the prime reason to implement this feature in the C# 5.0 compiler. You can repurpose this feature for tracing to get your hands on the method name of your caller along other stuff very fast now. All infos are added during compile time which is much faster than other approaches like walking the stack. The example on MSDN shows the usage of this attribute with an example public static void TraceMessage(string message, [CallerMemberName] string memberName = "", [CallerFilePath] string sourceFilePath = "", [CallerLineNumber] int sourceLineNumber = 0) { Console.WriteLine("Hi {0} {1} {2}({3})", message, memberName, sourceFilePath, sourceLineNumber); }   When I do think of tracing I do usually want to have a API which allows me to Trace method enter and leave Trace messages with a severity like Info, Warning, Error When I do print a trace message it is very useful to print out method and type name as well. So your API must either be able to pass the method and type name as strings or extract it automatically via walking back one Stackframe and fetch the infos from there. The first glaring deficiency is that there is no CallerTypeAttribute yet because the C# compiler team was not satisfied with its performance.   A usable Trace Api might therefore look like   enum TraceTypes { None = 0, EnterLeave = 1 << 0, Info = 1 << 1, Warn = 1 << 2, Error = 1 << 3 } class Tracer : IDisposable { string Type; string Method; public Tracer(string type, string method) { Type = type; Method = method; if (IsEnabled(TraceTypes.EnterLeave,Type, Method)) { } } private bool IsEnabled(TraceTypes traceTypes, string Type, string Method) { // Do checking here if tracing is enabled return false; } public void Info(string fmt, params object[] args) { } public void Warn(string fmt, params object[] args) { } public void Error(string fmt, params object[] args) { } public static void Info(string type, string method, string fmt, params object[] args) { } public static void Warn(string type, string method, string fmt, params object[] args) { } public static void Error(string type, string method, string fmt, params object[] args) { } public void Dispose() { // trace method leave } } This minimal trace API is very fast but hard to maintain since you need to pass in the type and method name as hard coded strings which can change from time to time. But now we have at least CallerMemberName to rid of the explicit method parameter right? Not really. Since any acceptable usable trace Api should have a method signature like Tracexxx(… string fmt, params [] object args) we not able to add additional optional parameters after the args array. If we would put it before the format string we would need to make it optional as well which would mean the compiler would need to figure out what our trace message and arguments are (not likely) or we would need to specify everything explicitly just like before . There are ways around this by providing a myriad of overloads which in the end are routed to the very same method but that is ugly. I am not sure if nobody inside MS agrees that the above API is reasonable to have or (more likely) that the whole talk about you can use this feature for diagnostic purposes was not a core feature at all but a simple byproduct of making the life of INotifyPropertyChanged implementers easier. A way around this would be to allow for variable argument arrays after the params keyword another set of optional arguments which are always filled by the compiler but I do not know if this is an easy one. The thing I am missing much more is the not provided CallerType attribute. But not in the way you would think of. In the API above I did add some filtering based on method and type to stay as fast as possible for types where tracing is not enabled at all. It should be no more expensive than an additional method call and a bool variable check if tracing for this type is enabled at all. The data is tightly bound to the calling type and method and should therefore become part of the static type instance. Since extending the CLR type system for tracing is not something I do expect to happen I have come up with an alternative approach which allows me basically to attach run time data to any existing type object in super fast way. The key to success is the usage of generics.   class Tracer<T> : IDisposable { string Method; public Tracer(string method) { if (TraceData<T>.Instance.Enabled.HasFlag(TraceTypes.EnterLeave)) { } } public void Dispose() { if (TraceData<T>.Instance.Enabled.HasFlag(TraceTypes.EnterLeave)) { } } public static void Info(string fmt, params object[] args) { } /// <summary> /// Every type gets its own instance with a fresh set of variables to describe the /// current filter status. /// </summary> /// <typeparam name="T"></typeparam> internal class TraceData<UsingType> { internal static TraceData<UsingType> Instance = new TraceData<UsingType>(); public bool IsInitialized = false; // flag if we need to reinit the trace data in case of reconfigured trace settings at runtime public TraceTypes Enabled = TraceTypes.None; // Enabled trace levels for this type } } We do not need to pass the type as string or Type object to the trace Api. Instead we define a generic Api that accepts the using type as generic parameter. Then we can create a TraceData static instance which is due to the nature of generics a fresh instance for every new type parameter. My tests on my home machine have shown that this approach is as fast as a simple bool flag check. If you have an application with many types using tracing you do not want to bring the app down by simply enabling tracing for one special rarely used type. The trace filter performance for the types which are not enabled must be therefore the fasted code path. This approach has the nice side effect that if you store the TraceData instances in one global list you can reconfigure tracing at runtime safely by simply setting the IsInitialized flag to false. A similar effect can be achieved with a global static Dictionary<Type,TraceData> object but big hash tables have random memory access semantics which is bad for cache locality and you always need to pay for the lookup which involves hash code generation, equality check and an indexed array access. The generic version is wicked fast and allows you to add more features to your tracing Api with minimal perf overhead. But it is cumbersome to write the generic type argument always explicitly and worse if you do refactor code and move parts of it to other classes it might be that you cannot configure tracing correctly. I would like therefore to decorate my type with an attribute [CallerType] class Tracer<T> : IDisposable to tell the compiler to fill in the generic type argument automatically. class Program { static void Main(string[] args) { using (var t = new Tracer()) // equivalent to new Tracer<Program>() { That would be really useful and super fast since you do not need to pass any type object around but you do have full type infos at hand. This change would be breaking if another non generic type exists in the same namespace where now the generic counterpart would be preferred. But this is an acceptable risk in my opinion since you can today already get conflicts if two generic types of the same name are defined in different namespaces. This would be only a variation of this issue. When you do think about this further you can add more features like to trace the exception in your Dispose method if the method is left with an exception with that little trick I did write some time ago. You can think of tracing as a super fast and configurable switch to write data to an output destination or to execute alternative actions. With such an infrastructure you can e.g. Reconfigure tracing at run time. Take a memory dump when a specific method is left with a specific exception. Throw an exception when a specific trace statement is hit (useful for testing error conditions). Execute a passed delegate which e.g. dumps additional state when enabled. Write data to an in memory ring buffer and dump it when specific events do occur (e.g. method is left with an exception, triggered from outside). Write data to an output device. …. This stuff is really useful to have when your code is in production on a mission critical server and you need to find the root cause of sporadic crashes of your application. It could be a buggy graphics card driver which throws access violations into your application (ok with .NET 4 not anymore except if you enable a compatibility flag) where you would like to have a minidump or you have reached after two weeks of operation a state where you need a full memory dump at a specific point in time in the middle of an transaction. At my older machine I do get with this super fast approach 50 million traces/s when tracing is disabled. When I do know that tracing is enabled for this type I can walk the stack by using StackFrameHelper.GetStackFramesInternal to check further if a specific action or output device is configured for this method which is about 2-3 times faster than the regular StackTrace class. Even with one String.Format I am down to 3 million traces/s so performance is not so important anymore since I do want to do something now. The CallerMemberName feature of the C# 5 compiler is nice but I would have preferred to get direct access to the MethodHandle and not to the stringified version of it. But I really would like to see a CallerType attribute implemented to fill in the generic type argument of the call site to augment the static CLR type data with run time data.

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• Is it possible to implement bitwise operators using integer arithmetic?

  - by Statement

  Hello World! I am facing a rather peculiar problem. I am working on a compiler for an architecture that doesn't support bitwise operations. However, it handles signed 16 bit integer arithmetics and I was wondering if it would be possible to implement bitwise operations using only: Addition (c = a + b) Subtraction (c = a - b) Division (c = a / b) Multiplication (c = a * b) Modulus (c = a % b) Minimum (c = min(a, b)) Maximum (c = max(a, b)) Comparisons (c = (a < b), c = (a == b), c = (a <= b), et.c.) Jumps (goto, for, et.c.) The bitwise operations I want to be able to support are: Or (c = a | b) And (c = a & b) Xor (c = a ^ b) Left Shift (c = a << b) Right Shift (c = a b) (All integers are signed so this is a problem) Signed Shift (c = a b) One's Complement (a = ~b) (Already found a solution, see below) Normally the problem is the other way around; how to achieve arithmetic optimizations using bitwise hacks. However not in this case. Writable memory is very scarce on this architecture, hence the need for bitwise operations. The bitwise functions themselves should not use a lot of temporary variables. However, constant read-only data & instruction memory is abundant. A side note here also is that jumps and branches are not expensive and all data is readily cached. Jumps cost half the cycles as arithmetic (including load/store) instructions do. On other words, all of the above supported functions cost twice the cycles of a single jump. Some thoughts that might help: I figured out that you can do one's complement (negate bits) with the following code: // Bitwise one's complement b = ~a; // Arithmetic one's complement b = -1 - a; I also remember the old shift hack when dividing with a power of two so the bitwise shift can be expressed as: // Bitwise left shift b = a << 4; // Arithmetic left shift b = a * 16; // 2^4 = 16 // Signed right shift b = a >>> 4; // Arithmetic right shift b = a / 16; For the rest of the bitwise operations I am slightly clueless. I wish the architects of this architecture would have supplied bit-operations. I would also like to know if there is a fast/easy way of computing the power of two (for shift operations) without using a memory data table. A naive solution would be to jump into a field of multiplications: b = 1; switch (a) { case 15: b = b * 2; case 14: b = b * 2; // ... exploting fallthrough (instruction memory is magnitudes larger) case 2: b = b * 2; case 1: b = b * 2; } Or a Set & Jump approach: switch (a) { case 15: b = 32768; break; case 14: b = 16384; break; // ... exploiting the fact that a jump is faster than one additional mul // at the cost of doubling the instruction memory footprint. case 2: b = 4; break; case 1: b = 2; break; }

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• Log Blog

  - by PointsToShare

  © 2011 By: Dov Trietsch. All rights reserved Logging – A log blog In a another blog (Missing Fields and Defaults) I spoke about not doing a blog about log files, but then I looked at it again and realized that this is a nice opportunity to show a simple yet powerful tool and also deal with static variables and functions in C#. My log had to be able to answer a few simple logging rules:   To log or not to log? That is the question – Always log! That is the answer  Do we share a log? Even when a file is opened with a minimal lock, it does not share well and performance greatly suffers. So sharing a log is not a good idea. Also, when sharing, it is harder to find your particular entries and you have to establish rules about retention. My recommendation – Do Not Share!  How verbose? Your log can be very verbose – a good thing when testing, very terse – a good thing in day-to-day runs, or somewhere in between. You must be the judge. In my Blog, I elect to always report a run with start and end times, and always report errors. I normally use 5 levels of logging: 4 – write all, 3 – write more, 2 – write some, 1 – write errors and timing, 0 – write none. The code sample below is more general than that. It uses the config file to set the max log level and each call to the log assigns a level to the call itself. If the level is above the .config highest level, the line will not be written. Programmers decide which log belongs to which level and thus we can set the .config differently for production and testing.  Where do I keep the log? If your career is important to you, discuss this with the boss and with the system admin. We keep logs in the L: drive of our server and make sure that we have a directory for each app that needs a log. When adding a new app, add a new directory. The default location for the log is also found in the .config file Print One or Many? There are two options here:   1.     Print many, Open but once once – you start the stream and close it only when the program ends. This is what you can do when you perform in “batch” mode like in a console app or a stsadm extension.The advantage to this is that starting a closing a stream is expensive and time consuming and because we use a unique file, keeping it open for a long time does not cause contention problems. 2.     Print one entry at a time or Open many – every time you write a line, you start the stream, write to it and close it. This work for event receivers, feature receivers, and web parts. Here scalability requires us to create objects on the fly and get rid of them as soon as possible.  A default value of the onceOrMany resides in the .config.  All of the above applies to any windows or web application, not just SharePoint.  So as usual, here is a routine that does it all, and a few simple functions that call it for a variety of purposes.   So without further ado, here is app.config  <?xml version="1.0" encoding="utf-8" ?> <configuration>     <configSections>         <sectionGroup name="applicationSettings" type="System.Configuration.ApplicationSettingsGroup, System, Version=2.0.0.0, Culture=neutral, ublicKeyToken=b77a5c561934e089" >         <section name="statics.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />         </sectionGroup>     </configSections>     <applicationSettings>         <statics.Properties.Settings>             <setting name="oneOrMany" serializeAs="String">                 <value>False</value>             </setting>             <setting name="logURI" serializeAs="String">                 <value>C:\staticLog.txt</value>             </setting>             <setting name="highestLevel" serializeAs="String">                 <value>2</value>             </setting>         </statics.Properties.Settings>     </applicationSettings> </configuration>   And now the code:  In order to persist the variables between calls and also to be able to persist (or not to persist) the log file itself, I created an EventLog class with static variables and functions. Static functions do not need an instance of the class in order to work. If you ever wondered why our Main function is static, the answer is that something needs to run before instantiation so that other objects may be instantiated, and this is what the “static” Main does. The various logging functions and variables are created as static because they do not need instantiation and as a fringe benefit they remain un-destroyed between calls. The Main function here is just used for testing. Note that it does not instantiate anything, just uses the log functions. This is possible because the functions are static. Also note that the function calls are of the form: Class.Function.  using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.IO; namespace statics {       class Program     {         static void Main(string[] args)         {             //write a single line             EventLog.LogEvents("ha ha", 3, "C:\\hahafile.txt", 4, true, false);             //this single line will not be written because the msgLevel is too high             EventLog.LogEvents("baba", 3, "C:\\babafile.txt", 2, true, false);             //The next 4 lines will be written in succession - no closing             EventLog.LogLine("blah blah", 1);             EventLog.LogLine("da da", 1);             EventLog.LogLine("ma ma", 1);             EventLog.LogLine("lah lah", 1);             EventLog.CloseLog(); // log will close             //now with specific functions             EventLog.LogSingleLine("one line", 1);             //this is just a test, the log is already closed             EventLog.CloseLog();         }     }     public class EventLog     {         public static string logURI = Properties.Settings.Default.logURI;         public static bool isOneLine = Properties.Settings.Default.oneOrMany;         public static bool isOpen = false;         public static int highestLevel = Properties.Settings.Default.highestLevel;         public static StreamWriter sw;         /// <summary>         /// the program will "print" the msg into the log         /// unless msgLevel is > msgLimit         /// onceOrMany is true when once - the program will open the log         /// print the msg and close the log. False when many the program will         /// keep the log open until close = true         /// normally all the arguments will come from the app.config         /// called by many overloads of logLine         /// </summary>         /// <param name="msg"></param>         /// <param name="msgLevel"></param>         /// <param name="logFileName"></param>         /// <param name="msgLimit"></param>         /// <param name="onceOrMany"></param>         /// <param name="close"></param>         public static void LogEvents(string msg, int msgLevel, string logFileName, int msgLimit, bool oneOrMany, bool close)         {             //to print or not to print             if (msgLevel <= msgLimit)             {                 //open the file. from the argument (logFileName) or from the config (logURI)                 if (!isOpen)                 {                     string logFile = logFileName;                     if (logFileName == "")                     {                         logFile = logURI;                     }                     sw = new StreamWriter(logFile, true);                     sw.WriteLine("Started At: " + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"));                     isOpen = true;                 }                 //print                 sw.WriteLine(msg);             }             //close when instructed             if (close || oneOrMany)             {                 if (isOpen)                 {                     sw.WriteLine("Ended At: " + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"));                     sw.Close();                     isOpen = false;                 }             }         }           /// <summary>         /// The simplest, just msg and level         /// </summary>         /// <param name="msg"></param>         /// <param name="msgLevel"></param>         public static void LogLine(string msg, int msgLevel)         {             //use the given msg and msgLevel and all others are defaults             LogEvents(msg, msgLevel, "", highestLevel, isOneLine, false);         }                 /// <summary>         /// one line at a time - open print close         /// </summary>         /// <param name="msg"></param>         /// <param name="msgLevel"></param>         public static void LogSingleLine(string msg, int msgLevel)         {             LogEvents(msg, msgLevel, "", highestLevel, true, true);         }           /// <summary>         /// used to close. high level, low limit, once and close are set         /// </summary>         /// <param name="close"></param>         public static void CloseLog()         {             LogEvents("", 15, "", 1, true, true);         }           }     }   }   That’s all folks!

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• CodePlex Daily Summary for Sunday, January 09, 2011

  CodePlex Daily Summary for Sunday, January 09, 2011Popular ReleasesEnhSim: EnhSim 2.2.10 BETA: 2.2.10 BETAThis release supports WoW patch 4.03a at level 85 To use this release, you must have the Microsoft Visual C++ 2010 Redistributable Package installed. This can be downloaded from http://www.microsoft.com/downloads/en/details.aspx?FamilyID=A7B7A05E-6DE6-4D3A-A423-37BF0912DB84 To use the GUI you must have the .NET 4.0 Framework installed. This can be downloaded from http://www.microsoft.com/downloads/en/details.aspx?FamilyID=9cfb2d51-5ff4-4491-b0e5-b386f32c0992 - Removed the part...TweetSharp: TweetSharp v2.0.0.0 - Preview 7: Documentation for this release may be found at http://tweetsharp.codeplex.com/wikipage?title=UserGuide&referringTitle=Documentation. Note: This code is currently preview quality. Preview 7 ChangesFixes the regression issue in OAuth from Preview 6 Preview 6 ChangesMaintenance release with user reported fixes Preview 5 ChangesMaintenance release with user reported fixes Third Party Library VersionsHammock v1.0.6: http://hammock.codeplex.com Json.NET 3.5 Release 8: http://json.codeplex.comExtended WPF Toolkit: Extended WPF Toolkit - 1.3.0: What's in the 1.3.0 Release?BusyIndicator ButtonSpinner ChildWindow ColorPicker - Updated (Breaking Changes) DateTimeUpDown - New Control Magnifier - New Control MaskedTextBox - New Control MessageBox NumericUpDown RichTextBox RichTextBoxFormatBar - Updated .NET 3.5 binaries and SourcePlease note: The Extended WPF Toolkit 3.5 is dependent on .NET Framework 3.5 and the WPFToolkit. You must install .NET Framework 3.5 and the WPFToolkit in order to use any features in the To...sNPCedit: sNPCedit v0.9d: added elementclient coordinate catcher to catch coordinates select a target (ingame) i.e. your char, npc or monster than click the button and coordinates+direction will be transfered to the selected row in the table corrected labels from Rot to Direction (because it is a vector)AutoLoL: AutoLoL v1.5.2: Implemented the Auto Updater Fix: Your settings will no longer be cleared with new releases of AutoLoL The mastery Editor and Browser now have their own tabs instead of nested tabs The Browser tab will only show the masteries matching ALL filters instead of just one Added a 'Browse' button in the Mastery Editor tab to open the Masteries Directory The Browser tab now shows a message when there are no mastery files in the Masteries Directory Fix: Fixed the Save As dialog again, for ...Ionics Isapi Rewrite Filter: 2.1 latest stable: V2.1 is stable, and is in maintenance mode. This is v2.1.1.25. It is a bug-fix release. There are no new features. 28629 29172 28722 27626 28074 29164 27659 27900 many documentation updates and fixes proper x64 build environment. This release includes x64 binaries in zip form, but no x64 MSI file. You'll have to manually install x64 servers, following the instructions in the documentation.StyleCop for ReSharper: StyleCop for ReSharper 5.1.14980.000: A considerable amount of work has gone into this release: Huge focus on performance around the violation scanning subsystem: - caching added to reduce IO operations around reading and merging of settings files - caching added to reduce creation of expensive objects Users should notice condsiderable perf boost and a decrease in memory usage. Bug Fixes: - StyleCop's new ObjectBasedEnvironment object does not resolve the StyleCop installation path, thus it does not return the correct path ...VivoSocial: VivoSocial 7.4.1: New release with bug fixes and updates for performance.SSH.NET Library: 2011.1.6: Fixes CommandTimeout default value is fixed to infinite. Port Forwarding feature improvements Memory leaks fixes New Features Add ErrorOccurred event to handle errors that occurred on different thread New and improve SFTP features SftpFile now has more attributes and some operations Most standard operations now available Allow specify encoding for command execution KeyboardInteractiveConnectionInfo class added for "keyboard-interactive" authentication. Add ability to specify bo....NET Extensions - Extension Methods Library for C# and VB.NET: Release 2011.03: Added lot's of new extensions and new projects for MVC and Entity Framework. object.FindTypeByRecursion Int32.InRange String.RemoveAllSpecialCharacters String.IsEmptyOrWhiteSpace String.IsNotEmptyOrWhiteSpace String.IfEmptyOrWhiteSpace String.ToUpperFirstLetter String.GetBytes String.ToTitleCase String.ToPlural DateTime.GetDaysInYear DateTime.GetPeriodOfDay IEnumberable.RemoveAll IEnumberable.Distinct ICollection.RemoveAll IList.Join IList.Match IList.Cast Array.IsNullOrEmpty Array.W...EFMVC - ASP.NET MVC 3 and EF Code First: EFMVC 0.5- ASP.NET MVC 3 and EF Code First: Demo web app ASP.NET MVC 3, Razor and EF Code FirstVidCoder: 0.8.0: Added x64 version. Made the audio output preview more detailed and accurate. If the chosen encoder or mixdown is incompatible with the source, the fallback that will be used is displayed. Added "Auto" to the audio mixdown choices. Reworked non-anamorphic size calculation to work better with non-standard pixel aspect ratios and cropping. Reworked Custom anamorphic to be more intuitive and allow display width to be set automatically (Thanks, Statick). Allowing higher bitrates for 6-ch....NET Voice Recorder: Auto-Tune Release: This is the source code and binaries to accompany the article on the Coding 4 Fun website. It is the Auto Tuner release of the .NET Voice Recorder application.BloodSim: BloodSim - 1.3.2.0: - Simulation Log is now automatically disabled and hidden when running 10 or more iterations - Hit and Expertise are now entered by Rating, and include option for a Racial Expertise bonus - Added option for boss to use a periodic magic ability (Dragon Breath) - Added option for boss to periodically Enrage, gaining a Damage/Attack Speed buffAllNewsManager.NET: AllNewsManager.NET 1.2.1: AllNewsManager.NET 1.2.1 It is a minor update from version 1.2xUnit.net - Unit Testing for .NET: xUnit.net 1.7 Beta: xUnit.net release 1.7 betaBuild #1533 Important notes for Resharper users: Resharper support has been moved to the xUnit.net Contrib project. Important note for TestDriven.net users: If you are having issues running xUnit.net tests in TestDriven.net, especially on 64-bit Windows, we strongly recommend you upgrade to TD.NET version 3.0 or later. This release adds the following new features: Added support for ASP.NET MVC 3 Added Assert.Equal(double expected, double actual, int precision)...Json.NET: Json.NET 4.0 Release 1: New feature - Added Windows Phone 7 project New feature - Added dynamic support to LINQ to JSON New feature - Added dynamic support to serializer New feature - Added INotifyCollectionChanged to JContainer in .NET 4 build New feature - Added ReadAsDateTimeOffset to JsonReader New feature - Added ReadAsDecimal to JsonReader New feature - Added covariance to IJEnumerable type parameter New feature - Added XmlSerializer style Specified property support New feature - Added ...ASP .NET MVC CMS (Content Management System): Atomic CMS 2.1.2: Atomic CMS 2.1.2 release notes Atomic CMS installation guide N2 CMS: 2.1: N2 is a lightweight CMS framework for ASP.NET. It helps you build great web sites that anyone can update. Major Changes Support for auto-implemented properties ({get;set;}, based on contribution by And Poulsen) All-round improvements and bugfixes File manager improvements (multiple file upload, resize images to fit) New image gallery Infinite scroll paging on news Content templates First time with N2? Try the demo site Download one of the template packs (above) and open the proj...Mobile Device Detection and Redirection: 0.1.11.10: IMPORTANT CHANGESThis release changes the way some WURFL capabilities and attributes are exposed to .NET developers. If you cast MobileCapabilities to return some values then please read the Release Note before implementing this release. The following code snippet can be used to access any WURFL capability. For instance, if the device is a tablet: string capability = Request.Browser["is_tablet"]; SummaryNew attributes have been added to the redirect section: originalUrlAsQueryString If se...New Projects[OOBL] Projekt: Projekt iz kolegija Objektno Oblikovanje na Fakultetu Elektrotehnike i Racunarstva u Zagrebu.Aikido Glossary Reader: The Aikido Glossary Reader application makes it easier for Aikido students to search for Japanese terms used in martial arts training.AsyncFunc: AsyncFunc makes it easy to implement Event-based Asynchronous Pattern in .NET.BeijingAgricultureScience: ???????????BizTalk 5010 999 Generation: Create 5010 999 acknowledgement from the default 997 Generated by BizTalk ServerCheck if Knowledge Base fix is installed script: A handy script that checks if a knowledge base fix is installed or not.Coproject - rich project management: Coproject is a sample Silverlight application built on WCF RIA Services and Caliburn.Micro framework. It should demonstrate typical scenarios in business applications.DeskNote: DeskNote, makes taking and displaying a notes a lot easier. Have your notes on your desktop, write your notes in a text file and it will be automatically displayed on the desktop. DriveBackup: Are you tired of losing data? And do you sometimes forget to backup your data? Then this program is right for you, one-time setup with each new removable disk and after that Drive Backup instantly backs up your data in the background, without you pushing a button.ELSEngine XNA Game OS Engine: XNA Game Operating System Engine, designed to handle and make easy to use Interface, Interface assets, game screens, menus, controls, and more. Designed to be adaptable to XBOX or Windows, and to ANY style game.FermaProject: Team Ferma ProjectHalfNetworkNET: HalfNetworkNET makes it easier for <target user group> to <activity>. You'll no longer have to <activity>. It's developed in C++/CLILFS Record: LFS Record is a camera animation and video recording tool for Live for Speed users. It doesn't replace programs like Fraps 100%, but in most cases you'll find LFS Record allows a lot more freedom and control. It's developed in C# using WPF .net 4.MPC HC Web remote: A Web interface for Media Player Classic Home Cinema. Designed especialy for smart phones. Tested on Nokia 5800, but in theory it works on all smart phones with wifi & a browser.MSMS2CMP: Very simple application to swap particular strings (MSMS and CMPD number) in .mgf files (results from Mascot search engine used to identify proteins by mass spectrometry data). This might be a kind of example of using Regex and Text File I/OMy Now Playing to Twitter: A Simple WinForm Program that can get what user is playing in Winamp and send a status to Twitter. It's wrote in VB.Net but some source code is port of MiniTwitter(http://minitwitter.codeplex.com)and uses tagLib-sharp library(https://github.com/mono/taglib-sharp)RPM Header for .NET: RPM Header for .NET allows a developer to access the headers of RPM Package Manager files. It's developed in C#.SilverMenu: SilverMenu brings some of the menu functionality of Silverlight for Windows Phone 7 to the XNA world.Smartgrid Smartmeter GRYD: The GRYD smartgrid and Smartmeter project shows features and capabilities like Demand Response, Smart Home Appliance Load Curtailments, DMS integration with SCADA etc. GRYD, Gryd.org is to teach you the technology, this is only for personal use and not commercial use.WakeMeQt: WakeMeQt is a smart alarm for the Nokia n810 (and probably n800) internet tablets. Using a Nintendo Wii remote as the sensor it monitors your movements during sleep and chooses the optimal time to wake you. It's developed in C++ using the Qt framework.WPF SplitButton & MenuButton: This WPF SplitButton and MenuButton implementation aims to be more robust and visual attractive than the other WPF split buttons available on CodePlex and elsewhere. The code is based on David Anson's implementation made available on his blog.Y2XMas: Merry Chirstmas - Happy New Year 2011 software

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• Parallel Classloading Revisited: Fully Concurrent Loading

  - by davidholmes

  Java 7 introduced support for parallel classloading. A description of that project and its goals can be found here: http://openjdk.java.net/groups/core-libs/ClassLoaderProposal.html The solution for parallel classloading was to add to each class loader a ConcurrentHashMap, referenced through a new field, parallelLockMap. This contains a mapping from class names to Objects to use as a classloading lock for that class name. This was then used in the following way: protected Class loadClass(String name, boolean resolve) throws ClassNotFoundException { synchronized (getClassLoadingLock(name)) { // First, check if the class has already been loaded Class c = findLoadedClass(name); if (c == null) { long t0 = System.nanoTime(); try { if (parent != null) { c = parent.loadClass(name, false); } else { c = findBootstrapClassOrNull(name); } } catch (ClassNotFoundException e) { // ClassNotFoundException thrown if class not found // from the non-null parent class loader } if (c == null) { // If still not found, then invoke findClass in order // to find the class. long t1 = System.nanoTime(); c = findClass(name); // this is the defining class loader; record the stats sun.misc.PerfCounter.getParentDelegationTime().addTime(t1 - t0); sun.misc.PerfCounter.getFindClassTime().addElapsedTimeFrom(t1); sun.misc.PerfCounter.getFindClasses().increment(); } } if (resolve) { resolveClass(c); } return c; } } Where getClassLoadingLock simply does: protected Object getClassLoadingLock(String className) { Object lock = this; if (parallelLockMap != null) { Object newLock = new Object(); lock = parallelLockMap.putIfAbsent(className, newLock); if (lock == null) { lock = newLock; } } return lock; } This approach is very inefficient in terms of the space used per map and the number of maps. First, there is a map per-classloader. As per the code above under normal delegation the current classloader creates and acquires a lock for the given class, checks if it is already loaded, then asks its parent to load it; the parent in turn creates another lock in its own map, checks if the class is already loaded and then delegates to its parent and so on till the boot loader is invoked for which there is no map and no lock. So even in the simplest of applications, you will have two maps (in the system and extensions loaders) for every class that has to be loaded transitively from the application's main class. If you knew before hand which loader would actually load the class the locking would only need to be performed in that loader. As it stands the locking is completely unnecessary for all classes loaded by the boot loader. Secondly, once loading has completed and findClass will return the class, the lock and the map entry is completely unnecessary. But as it stands, the lock objects and their associated entries are never removed from the map. It is worth understanding exactly what the locking is intended to achieve, as this will help us understand potential remedies to the above inefficiencies. Given this is the support for parallel classloading, the class loader itself is unlikely to need to guard against concurrent load attempts - and if that were not the case it is likely that the classloader would need a different means to protect itself rather than a lock per class. Ultimately when a class file is located and the class has to be loaded, defineClass is called which calls into the VM - the VM does not require any locking at the Java level and uses its own mutexes for guarding its internal data structures (such as the system dictionary). The classloader locking is primarily needed to address the following situation: if two threads attempt to load the same class, one will initiate the request through the appropriate loader and eventually cause defineClass to be invoked. Meanwhile the second attempt will block trying to acquire the lock. Once the class is loaded the first thread will release the lock, allowing the second to acquire it. The second thread then sees that the class has now been loaded and will return that class. Neither thread can tell which did the loading and they both continue successfully. Consider if no lock was acquired in the classloader. Both threads will eventually locate the file for the class, read in the bytecodes and call defineClass to actually load the class. In this case the first to call defineClass will succeed, while the second will encounter an exception due to an attempted redefinition of an existing class. It is solely for this error condition that the lock has to be used. (Note that parallel capable classloaders should not need to be doing old deadlock-avoidance tricks like doing a wait() on the lock object\!). There are a number of obvious things we can try to solve this problem and they basically take three forms: Remove the need for locking. This might be achieved by having a new version of defineClass which acts like defineClassIfNotPresent - simply returning an existing Class rather than triggering an exception. Increase the coarseness of locking to reduce the number of lock objects and/or maps. For example, using a single shared lockMap instead of a per-loader lockMap. Reduce the lifetime of lock objects so that entries are removed from the map when no longer needed (eg remove after loading, use weak references to the lock objects and cleanup the map periodically). There are pros and cons to each of these approaches. Unfortunately a significant "con" is that the API introduced in Java 7 to support parallel classloading has essentially mandated that these locks do in fact exist, and they are accessible to the application code (indirectly through the classloader if it exposes them - which a custom loader might do - and regardless they are accessible to custom classloaders). So while we can reason that we could do parallel classloading with no locking, we can not implement this without breaking the specification for parallel classloading that was put in place for Java 7. Similarly we might reason that we can remove a mapping (and the lock object) because the class is already loaded, but this would again violate the specification because it can be reasoned that the following assertion should hold true: Object lock1 = loader.getClassLoadingLock(name); loader.loadClass(name); Object lock2 = loader.getClassLoadingLock(name); assert lock1 == lock2; Without modifying the specification, or at least doing some creative wordsmithing on it, options 1 and 3 are precluded. Even then there are caveats, for example if findLoadedClass is not atomic with respect to defineClass, then you can have concurrent calls to findLoadedClass from different threads and that could be expensive (this is also an argument against moving findLoadedClass outside the locked region - it may speed up the common case where the class is already loaded, but the cost of re-executing after acquiring the lock could be prohibitive. Even option 2 might need some wordsmithing on the specification because the specification for getClassLoadingLock states "returns a dedicated object associated with the specified class name". The question is, what does "dedicated" mean here? Does it mean unique in the sense that the returned object is only associated with the given class in the current loader? Or can the object actually guard loading of multiple classes, possibly across different class loaders? So it seems that changing the specification will be inevitable if we wish to do something here. In which case lets go for something that more cleanly defines what we want to be doing: fully concurrent class-loading. Note: defineClassIfNotPresent is already implemented in the VM as find_or_define_class. It is only used if the AllowParallelDefineClass flag is set. This gives us an easy hook into existing VM mechanics. Proposal: Fully Concurrent ClassLoaders The proposal is that we expand on the notion of a parallel capable class loader and define a "fully concurrent parallel capable class loader" or fully concurrent loader, for short. A fully concurrent loader uses no synchronization in loadClass and the VM uses the "parallel define class" mechanism. For a fully concurrent loader getClassLoadingLock() can return null (or perhaps not - it doesn't matter as we won't use the result anyway). At present we have not made any changes to this method. All the parallel capable JDK classloaders become fully concurrent loaders. This doesn't require any code re-design as none of the mechanisms implemented rely on the per-name locking provided by the parallelLockMap. This seems to give us a path to remove all locking at the Java level during classloading, while retaining full compatibility with Java 7 parallel capable loaders. Fully concurrent loaders will still encounter the performance penalty associated with concurrent attempts to find and prepare a class's bytecode for definition by the VM. What this penalty is depends on the number of concurrent load attempts possible (a function of the number of threads and the application logic, and dependent on the number of processors), and the costs associated with finding and preparing the bytecodes. This obviously has to be measured across a range of applications. Preliminary webrevs: http://cr.openjdk.java.net/~dholmes/concurrent-loaders/webrev.hotspot/ http://cr.openjdk.java.net/~dholmes/concurrent-loaders/webrev.jdk/ Please direct all comments to the mailing list [email protected].

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• Why unhandled exceptions are useful

  - by Simon Cooper

  It’s the bane of most programmers’ lives – an unhandled exception causes your application or webapp to crash, an ugly dialog gets displayed to the user, and they come complaining to you. Then, somehow, you need to figure out what went wrong. Hopefully, you’ve got a log file, or some other way of reporting unhandled exceptions (obligatory employer plug: SmartAssembly reports an application’s unhandled exceptions straight to you, along with the entire state of the stack and variables at that point). If not, you have to try and replicate it yourself, or do some psychic debugging to try and figure out what’s wrong. However, it’s good that the program crashed. Or, more precisely, it is correct behaviour. An unhandled exception in your application means that, somewhere in your code, there is an assumption that you made that is actually invalid. Coding assumptions Let me explain a bit more. Every method, every line of code you write, depends on implicit assumptions that you have made. Take this following simple method, that copies a collection to an array and includes an item if it isn’t in the collection already, using a supplied IEqualityComparer: public static T[] ToArrayWithItem( ICollection<T> coll, T obj, IEqualityComparer<T> comparer) { // check if the object is in collection already // using the supplied comparer foreach (var item in coll) { if (comparer.Equals(item, obj)) { // it's in the collection already // simply copy the collection to an array // and return it T[] array = new T[coll.Count]; coll.CopyTo(array, 0); return array; } } // not in the collection // copy coll to an array, and add obj to it // then return it T[] array = new T[coll.Count+1]; coll.CopyTo(array, 0); array[array.Length-1] = obj; return array; } What’s all the assumptions made by this fairly simple bit of code? coll is never null comparer is never null coll.CopyTo(array, 0) will copy all the items in the collection into the array, in the order defined for the collection, starting at the first item in the array. The enumerator for coll returns all the items in the collection, in the order defined for the collection comparer.Equals returns true if the items are equal (for whatever definition of ‘equal’ the comparer uses), false otherwise comparer.Equals, coll.CopyTo, and the coll enumerator will never throw an exception or hang for any possible input and any possible values of T coll will have less than 4 billion items in it (this is a built-in limit of the CLR) array won’t be more than 2GB, both on 32 and 64-bit systems, for any possible values of T (again, a limit of the CLR) There are no threads that will modify coll while this method is running and, more esoterically: The C# compiler will compile this code to IL according to the C# specification The CLR and JIT compiler will produce machine code to execute the IL on the user’s computer The computer will execute the machine code correctly That’s a lot of assumptions. Now, it could be that all these assumptions are valid for the situations this method is called. But if this does crash out with an exception, or crash later on, then that shows one of the assumptions has been invalidated somehow. An unhandled exception shows that your code is running in a situation which you did not anticipate, and there is something about how your code runs that you do not understand. Debugging the problem is the process of learning more about the new situation and how your code interacts with it. When you understand the problem, the solution is (usually) obvious. The solution may be a one-line fix, the rewrite of a method or class, or a large-scale refactoring of the codebase, but whatever it is, the fix for the crash will incorporate the new information you’ve gained about your own code, along with the modified assumptions. When code is running with an assumption or invariant it depended on broken, then the result is ‘undefined behaviour’. Anything can happen, up to and including formatting the entire disk or making the user’s computer sentient and start doing a good impression of Skynet. You might think that those can’t happen, but at Halting problem levels of generality, as soon as an assumption the code depended on is broken, the program can do anything. That is why it’s important to fail-fast and stop the program as soon as an invariant is broken, to minimise the damage that is done. What does this mean in practice? To start with, document and check your assumptions. As with most things, there is a level of judgement required. How you check and document your assumptions depends on how the code is used (that’s some more assumptions you’ve made), how likely it is a method will be passed invalid arguments or called in an invalid state, how likely it is the assumptions will be broken, how expensive it is to check the assumptions, and how bad things are likely to get if the assumptions are broken. Now, some assumptions you can assume unless proven otherwise. You can safely assume the C# compiler, CLR, and computer all run the method correctly, unless you have evidence of a compiler, CLR or processor bug. You can also assume that interface implementations work the way you expect them to; implementing an interface is more than simply declaring methods with certain signatures in your type. The behaviour of those methods, and how they work, is part of the interface contract as well. For example, for members of a public API, it is very important to document your assumptions and check your state before running the bulk of the method, throwing ArgumentException, ArgumentNullException, InvalidOperationException, or another exception type as appropriate if the input or state is wrong. For internal and private methods, it is less important. If a private method expects collection items in a certain order, then you don’t necessarily need to explicitly check it in code, but you can add comments or documentation specifying what state you expect the collection to be in at a certain point. That way, anyone debugging your code can immediately see what’s wrong if this does ever become an issue. You can also use DEBUG preprocessor blocks and Debug.Assert to document and check your assumptions without incurring a performance hit in release builds. On my coding soapbox… A few pet peeves of mine around assumptions. Firstly, catch-all try blocks: try { ... } catch { } A catch-all hides exceptions generated by broken assumptions, and lets the program carry on in an unknown state. Later, an exception is likely to be generated due to further broken assumptions due to the unknown state, causing difficulties when debugging as the catch-all has hidden the original problem. It’s much better to let the program crash straight away, so you know where the problem is. You should only use a catch-all if you are sure that any exception generated in the try block is safe to ignore. That’s a pretty big ask! Secondly, using as when you should be casting. Doing this: (obj as IFoo).Method(); or this: IFoo foo = obj as IFoo; ... foo.Method(); when you should be doing this: ((IFoo)obj).Method(); or this: IFoo foo = (IFoo)obj; ... foo.Method(); There’s an assumption here that obj will always implement IFoo. If it doesn’t, then by using as instead of a cast you’ve turned an obvious InvalidCastException at the point of the cast that will probably tell you what type obj actually is, into a non-obvious NullReferenceException at some later point that gives you no information at all. If you believe obj is always an IFoo, then say so in code! Let it fail-fast if not, then it’s far easier to figure out what’s wrong. Thirdly, document your assumptions. If an algorithm depends on a non-trivial relationship between several objects or variables, then say so. A single-line comment will do. Don’t leave it up to whoever’s debugging your code after you to figure it out. Conclusion It’s better to crash out and fail-fast when an assumption is broken. If it doesn’t, then there’s likely to be further crashes along the way that hide the original problem. Or, even worse, your program will be running in an undefined state, where anything can happen. Unhandled exceptions aren’t good per-se, but they give you some very useful information about your code that you didn’t know before. And that can only be a good thing.

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• Building Queries Systematically

  - by Jeremy Smyth

  The SQL language is a bit like a toolkit for data. It consists of lots of little fiddly bits of syntax that, taken together, allow you to build complex edifices and return powerful results. For the uninitiated, the many tools can be quite confusing, and it's sometimes difficult to decide how to go about the process of building non-trivial queries, that is, queries that are more than a simple SELECT a, b FROM c; A System for Building Queries When you're building queries, you could use a system like the following:  Decide which fields contain the values you want to use in our output, and how you wish to alias those fields Values you want to see in your output Values you want to use in calculations . For example, to calculate margin on a product, you could calculate price - cost and give it the alias margin. Values you want to filter with. For example, you might only want to see products that weigh more than 2Kg or that are blue. The weight or colour columns could contain that information. Values you want to order by. For example you might want the most expensive products first, and the least last. You could use the price column in descending order to achieve that. Assuming the fields you've picked in point 1 are in multiple tables, find the connections between those tables Look for relationships between tables and identify the columns that implement those relationships. For example, The Orders table could have a CustomerID field referencing the same column in the Customers table. Sometimes the problem doesn't use relationships but rests on a different field; sometimes the query is looking for a coincidence of fact rather than a foreign key constraint. For example you might have sales representatives who live in the same state as a customer; this information is normally not used in relationships, but if your query is for organizing events where sales representatives meet customers, it's useful in that query. In such a case you would record the names of columns at either end of such a connection. Sometimes relationships require a bridge, a junction table that wasn't identified in point 1 above but is needed to connect tables you need; these are used in "many-to-many relationships". In these cases you need to record the columns in each table that connect to similar columns in other tables. Construct a join or series of joins using the fields and tables identified in point 2 above. This becomes your FROM clause. Filter using some of the fields in point 1 above. This becomes your WHERE clause. Construct an ORDER BY clause using values from point 1 above that are relevant to the desired order of the output rows. Project the result using the remainder of the fields in point 1 above. This becomes your SELECT clause. A Worked Example   Let's say you want to query the world database to find a list of countries (with their capitals) and the change in GNP, using the difference between the GNP and GNPOld columns, and that you only want to see results for countries with a population greater than 100,000,000. Using the system described above, we could do the following:  The Country.Name and City.Name columns contain the name of the country and city respectively.  The change in GNP comes from the calculation GNP - GNPOld. Both those columns are in the Country table. This calculation is also used to order the output, in descending order To see only countries with a population greater than 100,000,000, you need the Population field of the Country table. There is also a Population field in the City table, so you'll need to specify the table name to disambiguate. You can also represent a number like 100 million as 100e6 instead of 100000000 to make it easier to read. Because the fields come from the Country and City tables, you'll need to join them. There are two relationships between these tables: Each city is hosted within a country, and the city's CountryCode column identifies that country. Also, each country has a capital city, whose ID is contained within the country's Capital column. This latter relationship is the one to use, so the relevant columns and the condition that uses them is represented by the following FROM clause:  FROM Country JOIN City ON Country.Capital = City.ID The statement should only return countries with a population greater than 100,000,000. Country.Population is the relevant column, so the WHERE clause becomes:  WHERE Country.Population > 100e6  To sort the result set in reverse order of difference in GNP, you could use either the calculation, or the position in the output (it's the third column): ORDER BY GNP - GNPOld or ORDER BY 3 Finally, project the columns you wish to see by constructing the SELECT clause: SELECT Country.Name AS Country, City.Name AS Capital,        GNP - GNPOld AS `Difference in GNP`  The whole statement ends up looking like this:  mysql> SELECT Country.Name AS Country, City.Name AS Capital, -> GNP - GNPOld AS `Difference in GNP` -> FROM Country JOIN City ON Country.Capital = City.ID -> WHERE Country.Population > 100e6 -> ORDER BY 3 DESC; +--------------------+------------+-------------------+ | Country            | Capital    | Difference in GNP | +--------------------+------------+-------------------+ | United States | Washington | 399800.00 | | China | Peking | 64549.00 | | India | New Delhi | 16542.00 | | Nigeria | Abuja | 7084.00 | | Pakistan | Islamabad | 2740.00 | | Bangladesh | Dhaka | 886.00 | | Brazil | Brasília | -27369.00 | | Indonesia | Jakarta | -130020.00 | | Russian Federation | Moscow | -166381.00 | | Japan | Tokyo | -405596.00 | +--------------------+------------+-------------------+ 10 rows in set (0.00 sec) Queries with Aggregates and GROUP BY While this system might work well for many queries, it doesn't cater for situations where you have complex summaries and aggregation. For aggregation, you'd start with choosing which columns to view in the output, but this time you'd construct them as aggregate expressions. For example, you could look at the average population, or the count of distinct regions.You could also perform more complex aggregations, such as the average of GNP per head of population calculated as AVG(GNP/Population). Having chosen the values to appear in the output, you must choose how to aggregate those values. A useful way to think about this is that every aggregate query is of the form X, Y per Z. The SELECT clause contains the expressions for X and Y, as already described, and Z becomes your GROUP BY clause. Ordinarily you would also include Z in the query so you see how you are grouping, so the output becomes Z, X, Y per Z.  As an example, consider the following, which shows a count of  countries and the average population per continent:  mysql> SELECT Continent, COUNT(Name), AVG(Population)     -> FROM Country     -> GROUP BY Continent; +---------------+-------------+-----------------+ | Continent     | COUNT(Name) | AVG(Population) | +---------------+-------------+-----------------+ | Asia          |          51 |   72647562.7451 | | Europe        |          46 |   15871186.9565 | | North America |          37 |   13053864.8649 | | Africa        |          58 |   13525431.0345 | | Oceania       |          28 |    1085755.3571 | | Antarctica    |           5 |          0.0000 | | South America |          14 |   24698571.4286 | +---------------+-------------+-----------------+ 7 rows in set (0.00 sec) In this case, X is the number of countries, Y is the average population, and Z is the continent. Of course, you could have more fields in the SELECT clause, and  more fields in the GROUP BY clause as you require. You would also normally alias columns to make the output more suited to your requirements. More Complex Queries  Queries can get considerably more interesting than this. You could also add joins and other expressions to your aggregate query, as in the earlier part of this post. You could have more complex conditions in the WHERE clause. Similarly, you could use queries such as these in subqueries of yet more complex super-queries. Each technique becomes another tool in your toolbox, until before you know it you're writing queries across 15 tables that take two pages to write out. But that's for another day...

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• Auto-hydrate your objects with ADO.NET

  - by Jake Rutherford

  Recently while writing the monotonous code for pulling data out of a DataReader to hydrate some objects in an application I suddenly wondered "is this really necessary?" You've probably asked yourself the same question, and many of you have: - Used a code generator - Used a ORM such as Entity Framework - Wrote the code anyway because you like busy work     In most of the cases I've dealt with when making a call to a stored procedure the column names match up with the properties of the object I am hydrating. Sure that isn't always the case, but most of the time it's 1 to 1 mapping.  Given that fact I whipped up the following method of hydrating my objects without having write all of the code. First I'll show the code, and then explain what it is doing.      /// <summary>     /// Abstract base class for all Shared objects.     /// </summary>     /// <typeparam name="T"></typeparam>     [Serializable, DataContract(Name = "{0}SharedBase")]     public abstract class SharedBase<T> where T : SharedBase<T>     {         private static List<PropertyInfo> cachedProperties;         /// <summary>         /// Hydrates derived class with values from record.         /// </summary>         /// <param name="dataRecord"></param>         /// <param name="instance"></param>         public static void Hydrate(IDataRecord dataRecord, T instance)         {             var instanceType = instance.GetType();                         //Caching properties to avoid repeated calls to GetProperties.             //Noticable performance gains when processing same types repeatedly.             if (cachedProperties == null)             {                 cachedProperties = instanceType.GetProperties().ToList();             }                         foreach (var property in cachedProperties)             {                 if (!dataRecord.ColumnExists(property.Name)) continue;                 var ordinal = dataRecord.GetOrdinal(property.Name);                 var isNullable = property.PropertyType.IsGenericType &&                                  property.PropertyType.GetGenericTypeDefinition() == typeof (Nullable<>);                 var isNull = dataRecord.IsDBNull(ordinal);                 var propertyType = property.PropertyType;                 if (isNullable)                 {                     if (!string.IsNullOrEmpty(propertyType.FullName))                     {                         var nullableType = Type.GetType(propertyType.FullName);                         propertyType = nullableType != null ? nullableType.GetGenericArguments()[0] : propertyType;                     }                 }                 switch (Type.GetTypeCode(propertyType))                 {                     case TypeCode.Int32:                         property.SetValue(instance,                                           (isNullable && isNull) ? (int?) null : dataRecord.GetInt32(ordinal), null);                         break;                     case TypeCode.Double:                         property.SetValue(instance,                                           (isNullable && isNull) ? (double?) null : dataRecord.GetDouble(ordinal),                                           null);                         break;                     case TypeCode.Boolean:                         property.SetValue(instance,                                           (isNullable && isNull) ? (bool?) null : dataRecord.GetBoolean(ordinal),                                           null);                         break;                     case TypeCode.String:                         property.SetValue(instance, (isNullable && isNull) ? null : isNull ? null : dataRecord.GetString(ordinal),                                           null);                         break;                     case TypeCode.Int16:                         property.SetValue(instance,                                           (isNullable && isNull) ? (int?) null : dataRecord.GetInt16(ordinal), null);                         break;                     case TypeCode.DateTime:                         property.SetValue(instance,                                           (isNullable && isNull)                                               ? (DateTime?) null                                               : dataRecord.GetDateTime(ordinal), null);                         break;                 }             }         }     }   Here is a class which utilizes the above: [Serializable] [DataContract] public class foo : SharedBase<foo> {     [DataMember]     public int? ID { get; set; }     [DataMember]     public string Name { get; set; }     [DataMember]     public string Description { get; set; }     [DataMember]     public string Subject { get; set; }     [DataMember]     public string Body { get; set; }            public foo(IDataRecord record)     {         Hydrate(record, this);                }     public foo() {} }   Explanation: - Class foo inherits from SharedBase specifying itself as the type. (NOTE SharedBase is abstract here in the event we want to provide additional methods which could be overridden by the instance class) public class foo : SharedBase<foo> - One of the foo class constructors accepts a data record which then calls the Hydrate method on SharedBase passing in the record and itself. public foo(IDataRecord record) {      Hydrate(record, this); } - Hydrate method on SharedBase will use reflection on the object passed in to determine its properties. At the same time, it will effectively cache these properties to avoid repeated expensive reflection calls public static void Hydrate(IDataRecord dataRecord, T instance) {      var instanceType = instance.GetType();      //Caching properties to avoid repeated calls to GetProperties.      //Noticable performance gains when processing same types repeatedly.      if (cachedProperties == null)      {           cachedProperties = instanceType.GetProperties().ToList();      } . . . - Hydrate method on SharedBase will iterate each property on the object and determine if a column with matching name exists in data record foreach (var property in cachedProperties) {      if (!dataRecord.ColumnExists(property.Name)) continue;      var ordinal = dataRecord.GetOrdinal(property.Name); . . . NOTE: ColumnExists is an extension method I put on IDataRecord which I’ll include at the end of this post. - Hydrate method will determine if the property is nullable and whether the value in the corresponding column of the data record has a null value var isNullable = property.PropertyType.IsGenericType && property.PropertyType.GetGenericTypeDefinition() == typeof (Nullable<>); var isNull = dataRecord.IsDBNull(ordinal); var propertyType = property.PropertyType; . . .  - If Hydrate method determines the property is nullable it will determine the underlying type and set propertyType accordingly - Hydrate method will set the value of the property based upon the propertyType   That’s it!!!   The magic here is in a few places. First, you may have noticed the following: public abstract class SharedBase<T> where T : SharedBase<T> This says that SharedBase can be created with any type and that for each type it will have it’s own instance. This is important because of the static members within SharedBase. We want this behavior because we are caching the properties for each type. If we did not handle things in this way only 1 type could be cached at a time, or, we’d need to create a collection that allows us to cache the properties for each type = not very elegant.   Second, in the constructor for foo you may have noticed this (literally): public foo(IDataRecord record) {      Hydrate(record, this); } I wanted the code for auto-hydrating to be as simple as possible. At first I wasn’t quite sure how I could call Hydrate on SharedBase within an instance of the class and pass in the instance itself. Fortunately simply passing in “this” does the trick. I wasn’t sure it would work until I tried it out, and fortunately it did.   So, to actually use this feature when utilizing ADO.NET you’d do something like the following:        public List<foo> GetFoo(int? fooId)         {             List<foo> fooList;             const string uspName = "usp_GetFoo";             using (var conn = new SqlConnection(_dbConnection))             using (var cmd = new SqlCommand(uspName, conn))             {                 cmd.CommandType = CommandType.StoredProcedure;                 cmd.Parameters.Add(new SqlParameter("@FooID", SqlDbType.Int)                                        {Direction = ParameterDirection.Input, Value = fooId});                 conn.Open();                 using (var dr = cmd.ExecuteReader())                 {                     fooList= (from row in dr.Cast<DbDataRecord>()                                             select                                                 new foo(row)                                            ).ToList();                 }             }             return fooList;         }   Nice! Instead of having line after line manually assigning values from data record to an object you simply create a new instance and pass in the data record. Note that there are certainly instances where columns returned from stored procedure do not always match up with property names. In this scenario you can still use the above method and simply do your manual assignments afterward.

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• parallel computation for an Iterator of elements in Java

  - by Brian Harris

  I've had the same need a few times now and wanted to get other thoughts on the right way to structure a solution. The need is to perform some operation on many elements on many threads without needing to have all elements in memory at once, just the ones under computation. As in, Iterables.partition is insufficient because it brings all elements into memory up front. Expressing it in code, I want to write a BulkCalc2 that does the same thing as BulkCalc1, just in parallel. Below is sample code that illustrates my best attempt. I'm not satisfied because it's big and ugly, but it does seem to accomplish my goals of keeping threads highly utilized until the work is done, propagating any exceptions during computation, and not having more than numThreads instances of BigThing necessarily in memory at once. I'll accept the answer which meets the stated goals in the most concise way, whether it's a way to improve my BulkCalc2 or a completely different solution. interface BigThing { int getId(); String getString(); } class Calc { // somewhat expensive computation double calc(BigThing bigThing) { Random r = new Random(bigThing.getString().hashCode()); double d = 0; for (int i = 0; i < 100000; i++) { d += r.nextDouble(); } return d; } } class BulkCalc1 { final Calc calc; public BulkCalc1(Calc calc) { this.calc = calc; } public TreeMap<Integer, Double> calc(Iterator<BigThing> in) { TreeMap<Integer, Double> results = Maps.newTreeMap(); while (in.hasNext()) { BigThing o = in.next(); results.put(o.getId(), calc.calc(o)); } return results; } } class SafeIterator<T> { final Iterator<T> in; SafeIterator(Iterator<T> in) { this.in = in; } synchronized T nextOrNull() { if (in.hasNext()) { return in.next(); } return null; } } class BulkCalc2 { final Calc calc; final int numThreads; public BulkCalc2(Calc calc, int numThreads) { this.calc = calc; this.numThreads = numThreads; } public TreeMap<Integer, Double> calc(Iterator<BigThing> in) { ExecutorService e = Executors.newFixedThreadPool(numThreads); List<Future<?>> futures = Lists.newLinkedList(); final Map<Integer, Double> results = new MapMaker().concurrencyLevel(numThreads).makeMap(); final SafeIterator<BigThing> it = new SafeIterator<BigThing>(in); for (int i = 0; i < numThreads; i++) { futures.add(e.submit(new Runnable() { @Override public void run() { while (true) { BigThing o = it.nextOrNull(); if (o == null) { return; } results.put(o.getId(), calc.calc(o)); } } })); } e.shutdown(); for (Future<?> future : futures) { try { future.get(); } catch (InterruptedException ex) { // swallowing is OK } catch (ExecutionException ex) { throw Throwables.propagate(ex.getCause()); } } return new TreeMap<Integer, Double>(results); } }

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• Introducing Oracle Multitenant

  - by OracleMultitenant

  0 0 1 1142 6510 Oracle Corporation 54 15 7637 14.0 Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-language:JA;} The First Database Designed for the Cloud Today Oracle announced the general availability (GA) of Oracle Database 12c, the first database designed for the Cloud. Oracle Multitenant, new with Oracle Database 12c, is a key component of this – a new architecture for consolidating databases and simplifying operations in the Cloud. With this, the inaugural post in the Multitenant blog, my goal is to start the conversation about Oracle Multitenant. We are very proud of this new architecture, which we view as a major advance for Oracle. Customers, partners and analysts who have had previews are very excited about its capabilities and its flexibility. This high level review of Oracle Multitenant will touch on our design considerations and how we re-architected our database for the cloud. I’ll briefly describe our new multitenant architecture and explain it’s key benefits. Finally I’ll mention some of the major use cases we see for Oracle Multitenant. Industry Trends We always start by talking to our customers about the pressures and challenges they’re facing and what trends they’re seeing in the industry. Some things don’t change. They face the same pressures and the same requirements as ever: Pressure to do more with less; be faster, leaner, cheaper, and deliver services 24/7. Big companies have achieved scale. Now they want to realize economies of scale. As ever, DBAs are faced with the challenges of patching and upgrading large numbers of databases, and provisioning new ones.  Requirements are familiar: Performance, scalability, reliability and high availability are non-negotiable. They need ever more security in this threatening climate. There’s no time to stop and retool with new applications. What’s new are the trends. These are the techniques to use to respond to these pressures within the constraints of the requirements. With the advent of cloud computing and availability of massively powerful servers – even engineered systems such as Exadata – our customers want to consolidate many applications into fewer larger servers. There’s a move to standardized services – even self-service. Consolidation Consolidation is not new; companies have tried various different approaches to consolidation of databases in the cloud. One approach is to partition a powerful server between several virtual machines, one per application. A downside of this is that you have the resource and management overheads of OS and RDBMS per VM – that is, per application. Another is that you have replaced physical sprawl with virtual sprawl and virtual sprawl is still expensive to manage. In the dedicated database model, we have a single physical server supporting multiple databases, one per application. So there’s a shared OS overhead, but RDBMS process and memory overhead are replicated per application. Let's think about our traditional Oracle Database architecture. Every time we create a database, be it a production database, a development or a test database, what do we do? We create a set of files, we allocate a bunch of memory for managing the data, and we kick off a series of background processes. This is replicated for every one of the databases that we create. As more and more databases are fired up, these replicated overheads quickly consume the available server resources and this limits the number of applications we can run on any given server. In Oracle Database 11g and earlier the highest degree of consolidation could be achieved by what we call schema consolidation. In this model we have one big server with one big database. Individual applications are installed in separate schemas or table-owners. Database overheads are shared between all applications, which affords maximum consolidation. The shortcomings are that application changes are often required. There is no tenant isolation. One bad apple can spoil the whole batch. New Architecture & Benefits In Oracle Database 12c, we have a new multitenant architecture, featuring pluggable databases. This delivers all the resource utilization advantages of schema consolidation with none of the downsides. There are two parts to the term “pluggable database”: "pluggable", which is new, and "database", which is familiar.  Before we get to the exciting new stuff let’s discuss what hasn’t changed. A pluggable database is a fully functional Oracle database. It’s not watered down in any way. From the perspective of an application or an end user it hasn’t changed at all. This is very important because it means that no application changes are required to adopt this new architecture. There are many thousands of applications built on Oracle databases and they are all ready to run on Oracle Multitenant. So we have these self-contained pluggable databases (PDBs), and as their name suggests, they are plugged into a multitenant container database (CDB). The CDB behaves as a single database from the operations point of view. Very much as we had with the schema consolidation model, we only have a single set of Oracle background processes and a single, shared database memory requirement. This gives us very high consolidation density, which affords maximum reduction in capital expenses (CapEx). By performing management operations at the CDB level – “managing many as one” – we can achieve great reductions in operating expenses (OpEx) as well, but we retain granular control where appropriate. Furthermore, the “pluggability” capability gives us portability and this adds a tremendous amount of agility. We can simply unplug a PDB from one CDB and plug it into another CDB, for example to move it from one SLA tier to another. I'll explore all these new capabilities in much more detail in a future posting.  Use Cases We can identify a number of use cases for Oracle Multitenant. Here are a few of the major ones. 0 0 1 113 650 Oracle Corporation 5 1 762 14.0 Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-language:JA;} Development / Testing where individual engineers need rapid provisioning and recycling of private copies of a few "master test databases" Consolidation of disparate applications using fewer, more powerful servers Software as a Service deploying separate copies of identical applications to individual tenants Database as a Service typically self-service provisioning of databases on the private cloud Application Distribution from ISV / Installation by Customer Eliminating many typical installation steps (create schema, import seed data, import application code PL/SQL…) - just plug in a PDB! High volume data distribution literally via disk drives in envelopes distributed by truck! - distribution of things like GIS or MDM master databases …various others! Benefits Previous approaches to consolidation have involved a trade-off between reductions in Capital Expenses (CapEx) and Operating Expenses (OpEx), and they’ve usually come at the expense of agility. With Oracle Multitenant you can have your cake and eat it: Minimize CapEx More Applications per server Minimize OpEx Manage many as one Standardized procedures and services Rapid provisioning Maximize Agility Cloning for development and testing Portability through pluggability Scalability with RAC Ease of Adoption Applications run unchanged It’s a pure deployment choice. Neither the database backend nor the application needs to be changed. In future postings I’ll explore various aspects in more detail. However, if you feel compelled to devour everything you can about Oracle Multitenant this very minute, have no fear. Visit the Multitenant page on OTN and explore the various resources we have available there. Among these, Oracle Distinguished Product Manager Bryn Llewellyn has written an excellent, thorough, and exhaustively detailed White Paper about Oracle Multitenant, which is available here.  Follow me  I tweet @OraclePDB #OracleMultitenant

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• Inside the DLR – Invoking methods

  - by Simon Cooper

  So, we’ve looked at how a dynamic call is represented in a compiled assembly, and how the dynamic lookup is performed at runtime. The last piece of the puzzle is how the resolved method gets invoked, and that is the subject of this post. Invoking methods As discussed in my previous posts, doing a full lookup and bind at runtime each and every single time the callsite gets invoked would be far too slow to be usable. The results obtained from the callsite binder must to be cached, along with a series of conditions to determine whether the cached result can be reused. So, firstly, how are the conditions represented? These conditions can be anything; they are determined entirely by the semantics of the language the binder is representing. The binder has to be able to return arbitary code that is then executed to determine whether the conditions apply or not. Fortunately, .NET 4 has a neat way of representing arbitary code that can be easily combined with other code – expression trees. All the callsite binder has to return is an expression (called a ‘restriction’) that evaluates to a boolean, returning true when the restriction passes (indicating the corresponding method invocation can be used) and false when it does’t. If the bind result is also represented in an expression tree, these can be combined easily like so: if ([restriction is true]) { [invoke cached method] } Take my example from my previous post: public class ClassA { public static void TestDynamic() { CallDynamic(new ClassA(), 10); CallDynamic(new ClassA(), "foo"); } public static void CallDynamic(dynamic d, object o) { d.Method(o); } public void Method(int i) {} public void Method(string s) {} } When the Method(int) method is first bound, along with an expression representing the result of the bind lookup, the C# binder will return the restrictions under which that bind can be reused. In this case, it can be reused if the types of the parameters are the same: if (thisArg.GetType() == typeof(ClassA) && arg1.GetType() == typeof(int)) { thisClassA.Method(i); } Caching callsite results So, now, it’s up to the callsite to link these expressions returned from the binder together in such a way that it can determine which one from the many it has cached it should use. This caching logic is all located in the System.Dynamic.UpdateDelegates class. It’ll help if you’ve got this type open in a decompiler to have a look yourself. For each callsite, there are 3 layers of caching involved: The last method invoked on the callsite. All methods that have ever been invoked on the callsite. All methods that have ever been invoked on any callsite of the same type. We’ll cover each of these layers in order Level 1 cache: the last method called on the callsite When a CallSite<T> object is first instantiated, the Target delegate field (containing the delegate that is called when the callsite is invoked) is set to one of the UpdateAndExecute generic methods in UpdateDelegates, corresponding to the number of parameters to the callsite, and the existance of any return value. These methods contain most of the caching, invoke, and binding logic for the callsite. The first time this method is invoked, the UpdateAndExecute method finds there aren’t any entries in the caches to reuse, and invokes the binder to resolve a new method. Once the callsite has the result from the binder, along with any restrictions, it stitches some extra expressions in, and replaces the Target field in the callsite with a compiled expression tree similar to this (in this example I’m assuming there’s no return value): if ([restriction is true]) { [invoke cached method] return; } if (callSite._match) { _match = false; return; } else { UpdateAndExecute(callSite, arg0, arg1, ...); } Woah. What’s going on here? Well, this resulting expression tree is actually the first level of caching. The Target field in the callsite, which contains the delegate to call when the callsite is invoked, is set to the above code compiled from the expression tree into IL, and then into native code by the JIT. This code checks whether the restrictions of the last method that was invoked on the callsite (the ‘primary’ method) match, and if so, executes that method straight away. This means that, the next time the callsite is invoked, the first code that executes is the restriction check, executing as native code! This makes this restriction check on the primary cached delegate very fast. But what if the restrictions don’t match? In that case, the second part of the stitched expression tree is executed. What this section should be doing is calling back into the UpdateAndExecute method again to resolve a new method. But it’s slightly more complicated than that. To understand why, we need to understand the second and third level caches. Level 2 cache: all methods that have ever been invoked on the callsite When a binder has returned the result of a lookup, as well as updating the Target field with a compiled expression tree, stitched together as above, the callsite puts the same compiled expression tree in an internal list of delegates, called the rules list. This list acts as the level 2 cache. Why use the same delegate? Stitching together expression trees is an expensive operation. You don’t want to do it every time the callsite is invoked. Ideally, you would create one expression tree from the binder’s result, compile it, and then use the resulting delegate everywhere in the callsite. But, if the same delegate is used to invoke the callsite in the first place, and in the caches, that means each delegate needs two modes of operation. An ‘invoke’ mode, for when the delegate is set as the value of the Target field, and a ‘match’ mode, used when UpdateAndExecute is searching for a method in the callsite’s cache. Only in the invoke mode would the delegate call back into UpdateAndExecute. In match mode, it would simply return without doing anything. This mode is controlled by the _match field in CallSite<T>. The first time the callsite is invoked, _match is false, and so the Target delegate is called in invoke mode. Then, if the initial restriction check fails, the Target delegate calls back into UpdateAndExecute. This method sets _match to true, then calls all the cached delegates in the rules list in match mode to try and find one that passes its restrictions, and invokes it. However, there needs to be some way for each cached delegate to inform UpdateAndExecute whether it passed its restrictions or not. To do this, as you can see above, it simply re-uses _match, and sets it to false if it did not pass the restrictions. This allows the code within each UpdateAndExecute method to check for cache matches like so: foreach (T cachedDelegate in Rules) { callSite._match = true; cachedDelegate(); // sets _match to false if restrictions do not pass if (callSite._match) { // passed restrictions, and the cached method was invoked // set this delegate as the primary target to invoke next time callSite.Target = cachedDelegate; return; } // no luck, try the next one... } Level 3 cache: all methods that have ever been invoked on any callsite with the same signature The reason for this cache should be clear – if a method has been invoked through a callsite in one place, then it is likely to be invoked on other callsites in the codebase with the same signature. Rather than living in the callsite, the ‘global’ cache for callsite delegates lives in the CallSiteBinder class, in the Cache field. This is a dictionary, typed on the callsite delegate signature, providing a RuleCache<T> instance for each delegate signature. This is accessed in the same way as the level 2 callsite cache, by the UpdateAndExecute methods. When a method is matched in the global cache, it is copied into the callsite and Target cache before being executed. Putting it all together So, how does this all fit together? Like so (I’ve omitted some implementation & performance details): That, in essence, is how the DLR performs its dynamic calls nearly as fast as statically compiled IL code. Extensive use of expression trees, compiled to IL and then into native code. Multiple levels of caching, the first of which executes immediately when the dynamic callsite is invoked. And a clever re-use of compiled expression trees that can be used in completely different contexts without being recompiled. All in all, a very fast and very clever reflection caching mechanism.

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