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• I am having a problem of class cast exception. Can anyone please help me out?

  - by Piyush

  This is my code: package com.example.userpage; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; public class UserPage extends Activity { String tv,tv1; EditText name,pass; TextView x,y; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Button button = (Button) findViewById(R.id.widget44); button.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { name.setText(" "); pass.setText(" "); } }); x = (TextView) findViewById(R.id.widget46); y = (TextView) findViewById(R.id.widget47); name = (EditText)findViewById(R.id.widget41); pass = (EditText)findViewById(R.id.widget42); Button button1 = (Button) findViewById(R.id.widget45); button1.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { tv= name.getText().toString(); tv1 = pass.getText().toString(); x.setText(tv); y.setText(tv1); } }); } } And this is my log cat: 02-16 12:24:30.488: DEBUG/AndroidRuntime(973): >>>>>>>>>>>>>> AndroidRuntime START <<<<<<<<<<<<<< 02-16 12:24:30.488: DEBUG/AndroidRuntime(973): CheckJNI is ON 02-16 12:24:31.208: DEBUG/AndroidRuntime(973): --- registering native functions --- 02-16 12:24:33.498: DEBUG/AndroidRuntime(973): Shutting down VM 02-16 12:24:33.537: DEBUG/dalvikvm(973): Debugger has detached; object registry had 1 entries 02-16 12:24:33.537: INFO/AndroidRuntime(973): NOTE: attach of thread 'Binder Thread #3' failed 02-16 12:24:34.917: DEBUG/AndroidRuntime(981): >>>>>>>>>>>>>> AndroidRuntime START <<<<<<<<<<<<<< 02-16 12:24:34.927: DEBUG/AndroidRuntime(981): CheckJNI is ON 02-16 12:24:35.617: DEBUG/AndroidRuntime(981): --- registering native functions --- 02-16 12:24:38.029: INFO/ActivityManager(67): Starting activity: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10000000 cmp=com.example.userpage/.UserPage } 02-16 12:24:38.129: DEBUG/AndroidRuntime(981): Shutting down VM 02-16 12:24:38.160: DEBUG/dalvikvm(981): Debugger has detached; object registry had 1 entries 02-16 12:24:38.168: INFO/AndroidRuntime(981): NOTE: attach of thread 'Binder Thread #3' failed 02-16 12:25:12.028: DEBUG/AndroidRuntime(990): >>>>>>>>>>>>>> AndroidRuntime START <<<<<<<<<<<<<< 02-16 12:25:12.038: DEBUG/AndroidRuntime(990): CheckJNI is ON 02-16 12:25:12.708: DEBUG/AndroidRuntime(990): --- registering native functions --- 02-16 12:25:15.178: DEBUG/dalvikvm(176): GC_EXPLICIT freed 114 objects / 5880 bytes in 115ms 02-16 12:25:15.318: DEBUG/PackageParser(67): Scanning package: /data/app/vmdl25170.tmp 02-16 12:25:15.588: INFO/PackageManager(67): Removing non-system package:com.example.userpage 02-16 12:25:15.597: INFO/ActivityManager(67): Force stopping package com.example.userpage uid=10036 02-16 12:25:15.648: INFO/Process(67): Sending signal. PID: 916 SIG: 9 02-16 12:25:15.877: INFO/UsageStats(67): Unexpected resume of com.android.launcher while already resumed in com.example.userpage 02-16 12:25:17.028: WARN/InputManagerService(67): Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@4400ecf8 02-16 12:25:17.928: DEBUG/PackageManager(67): Scanning package com.example.userpage 02-16 12:25:17.949: INFO/PackageManager(67): Package com.example.userpage codePath changed from /data/app/com.example.userpage-1.apk to /data/app/com.example.userpage-2.apk; Retaining data and using new 02-16 12:25:17.987: INFO/PackageManager(67): /data/app/com.example.userpage-2.apk changed; unpacking 02-16 12:25:18.037: DEBUG/installd(35): DexInv: --- BEGIN '/data/app/com.example.userpage-2.apk' --- 02-16 12:25:18.737: DEBUG/dalvikvm(997): DexOpt: load 81ms, verify 112ms, opt 6ms 02-16 12:25:18.768: DEBUG/installd(35): DexInv: --- END '/data/app/com.example.userpage-2.apk' (success) --- 02-16 12:25:18.799: INFO/ActivityManager(67): Force stopping package com.example.userpage uid=10036 02-16 12:25:18.808: WARN/PackageManager(67): Code path for pkg : com.example.userpage changing from /data/app/com.example.userpage-1.apk to /data/app/com.example.userpage-2.apk 02-16 12:25:18.839: WARN/PackageManager(67): Resource path for pkg : com.example.userpage changing from /data/app/com.example.userpage-1.apk to /data/app/com.example.userpage-2.apk 02-16 12:25:18.868: DEBUG/PackageManager(67): Activities: com.example.userpage.UserPage 02-16 12:25:19.297: INFO/installd(35): move /data/dalvik-cache/data@[email protected]@classes.dex -> /data/dalvik-cache/data@[email protected]@classes.dex 02-16 12:25:19.297: DEBUG/PackageManager(67): New package installed in /data/app/com.example.userpage-2.apk 02-16 12:25:19.598: DEBUG/dalvikvm(67): GC_FOR_MALLOC freed 7979 objects / 516856 bytes in 246ms 02-16 12:25:20.498: INFO/ActivityManager(67): Force stopping package com.example.userpage uid=10036 02-16 12:25:20.708: DEBUG/dalvikvm(129): GC_EXPLICIT freed 124 objects / 5672 bytes in 157ms 02-16 12:25:21.838: DEBUG/dalvikvm(67): GC_EXPLICIT freed 4208 objects / 236264 bytes in 419ms 02-16 12:25:21.918: WARN/RecognitionManagerService(67): no available voice recognition services found 02-16 12:25:22.127: INFO/installd(35): unlink /data/dalvik-cache/data@[email protected]@classes.dex 02-16 12:25:22.478: DEBUG/AndroidRuntime(990): Shutting down VM 02-16 12:25:22.488: DEBUG/dalvikvm(990): Debugger has detached; object registry had 1 entries 02-16 12:25:22.588: INFO/AndroidRuntime(990): NOTE: attach of thread 'Binder Thread #3' failed 02-16 12:25:24.137: DEBUG/AndroidRuntime(1003): >>>>>>>>>>>>>> AndroidRuntime START <<<<<<<<<<<<<< 02-16 12:25:24.147: DEBUG/AndroidRuntime(1003): CheckJNI is ON 02-16 12:25:24.817: DEBUG/AndroidRuntime(1003): --- registering native functions --- 02-16 12:25:27.450: INFO/ActivityManager(67): Starting activity: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10000000 cmp=com.example.userpage/.UserPage } 02-16 12:25:27.628: DEBUG/AndroidRuntime(1003): Shutting down VM 02-16 12:25:27.780: INFO/AndroidRuntime(1003): NOTE: attach of thread 'Binder Thread #3' failed 02-16 12:25:28.018: DEBUG/dalvikvm(1003): Debugger has detached; object registry had 1 entries 02-16 12:25:28.148: INFO/ActivityManager(67): Start proc com.example.userpage for activity com.example.userpage/.UserPage: pid=1010 uid=10036 gids={} 02-16 12:25:30.308: DEBUG/AndroidRuntime(1010): Shutting down VM 02-16 12:25:30.308: WARN/dalvikvm(1010): threadid=1: thread exiting with uncaught exception (group=0x4001d800) 02-16 12:25:30.388: ERROR/AndroidRuntime(1010): FATAL EXCEPTION: main 02-16 12:25:30.388: ERROR/AndroidRuntime(1010): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.userpage/com.example.userpage.UserPage}: java.lang.ClassCastException: android.widget.TextView 02-16 12:25:30.388: ERROR/AndroidRuntime(1010): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663) 02-16 12:25:30.388: ERROR/AndroidRuntime(1010): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) 02-16 12:25:30.388: ERROR/AndroidRuntime(1010): at android.app.ActivityThread.access$2300(ActivityThread.java:125) 02-16 12:25:30.388: ERROR/AndroidRuntime(1010): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033) 02-16 12:25:30.388: ERROR/AndroidRuntime(1010): at android.os.Handler.dispatchMessage(Handler.java:99) 02-16 12:25:30.388: ERROR/AndroidRuntime(1010): at android.os.Looper.loop(Looper.java:123) 02-16 12:25:30.388: ERROR/AndroidRuntime(1010): at android.app.ActivityThread.main(ActivityThread.java:4627) 02-16 12:25:30.388: ERROR/AndroidRuntime(1010): at java.lang.reflect.Method.invokeNative(Native Method) 02-16 12:25:30.388: ERROR/AndroidRuntime(1010): at java.lang.reflect.Method.invoke(Method.java:521) 02-16 12:25:30.388: ERROR/AndroidRuntime(1010): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 02-16 12:25:30.388: ERROR/AndroidRuntime(1010): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 02-16 12:25:30.388: ERROR/AndroidRuntime(1010): at dalvik.system.NativeStart.main(Native Method) 02-16 12:25:30.388: ERROR/AndroidRuntime(1010): Caused by: java.lang.ClassCastException: android.widget.TextView 02-16 12:25:30.388: ERROR/AndroidRuntime(1010): at com.example.userpage.UserPage.onCreate(UserPage.java:35) 02-16 12:25:30.388: ERROR/AndroidRuntime(1010): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 02-16 12:25:30.388: ERROR/AndroidRuntime(1010): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627) 02-16 12:25:30.388: ERROR/AndroidRuntime(1010): ... 11 more 02-16 12:25:30.438: WARN/ActivityManager(67): Force finishing activity com.example.userpage/.UserPage 02-16 12:25:31.088: WARN/ActivityManager(67): Activity pause timeout for HistoryRecord{43f164f8 com.example.userpage/.UserPage} 02-16 12:25:32.588: DEBUG/dalvikvm(292): GC_EXPLICIT freed 46 objects / 2240 bytes in 6282ms 02-16 12:25:35.267: INFO/Process(1010): Sending signal. PID: 1010 SIG: 9 02-16 12:25:35.468: WARN/InputManagerService(67): Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@43e60a90 02-16 12:25:35.900: INFO/ActivityManager(67): Process com.example.userpage (pid 1010) has died. 02-16 12:25:38.278: DEBUG/dalvikvm(176): GC_EXPLICIT freed 172 objects / 12280 bytes in 127ms 02-16 12:25:43.011: WARN/ActivityManager(67): Activity destroy timeout for HistoryRecord{43f164f8 com.example.userpage/.UserPage} 02-16 12:28:12.698: DEBUG/AndroidRuntime(1019): >>>>>>>>>>>>>> AndroidRuntime START <<<<<<<<<<<<<< 02-16 12:28:12.711: DEBUG/AndroidRuntime(1019): CheckJNI is ON 02-16 12:28:13.367: DEBUG/AndroidRuntime(1019): --- registering native functions --- 02-16 12:28:15.998: DEBUG/dalvikvm(176): GC_EXPLICIT freed 114 objects / 5888 bytes in 183ms 02-16 12:28:16.539: DEBUG/PackageParser(67): Scanning package: /data/app/vmdl25171.tmp 02-16 12:28:16.867: INFO/PackageManager(67): Removing non-system package:com.example.userpage 02-16 12:28:16.867: INFO/ActivityManager(67): Force stopping package com.example.userpage uid=10036 02-16 12:28:17.277: DEBUG/PackageManager(67): Scanning package com.example.userpage 02-16 12:28:17.308: INFO/PackageManager(67): Package com.example.userpage codePath changed from /data/app/com.example.userpage-2.apk to /data/app/com.example.userpage-1.apk; Retaining data and using new 02-16 12:28:17.328: INFO/PackageManager(67): /data/app/com.example.userpage-1.apk changed; unpacking 02-16 12:28:17.367: DEBUG/installd(35): DexInv: --- BEGIN '/data/app/com.example.userpage-1.apk' --- 02-16 12:28:18.357: DEBUG/dalvikvm(1026): DexOpt: load 85ms, verify 114ms, opt 6ms 02-16 12:28:18.398: DEBUG/installd(35): DexInv: --- END '/data/app/com.example.userpage-1.apk' (success) --- 02-16 12:28:18.428: INFO/ActivityManager(67): Force stopping package com.example.userpage uid=10036 02-16 12:28:18.438: WARN/PackageManager(67): Code path for pkg : com.example.userpage changing from /data/app/com.example.userpage-2.apk to /data/app/com.example.userpage-1.apk 02-16 12:28:18.477: WARN/PackageManager(67): Resource path for pkg : com.example.userpage changing from /data/app/com.example.userpage-2.apk to /data/app/com.example.userpage-1.apk 02-16 12:28:18.477: DEBUG/PackageManager(67): Activities: com.example.userpage.UserPage 02-16 12:28:18.977: INFO/installd(35): move /data/dalvik-cache/data@[email protected]@classes.dex -> /data/dalvik-cache/data@[email protected]@classes.dex 02-16 12:28:18.988: DEBUG/PackageManager(67): New package installed in /data/app/com.example.userpage-1.apk 02-16 12:28:19.528: DEBUG/dalvikvm(67): GC_FOR_MALLOC freed 6733 objects / 459728 bytes in 211ms 02-16 12:28:20.138: INFO/ActivityManager(67): Force stopping package com.example.userpage uid=10036 02-16 12:28:20.368: DEBUG/dalvikvm(129): GC_EXPLICIT freed 892 objects / 48744 bytes in 175ms 02-16 12:28:21.317: WARN/RecognitionManagerService(67): no available voice recognition services found 02-16 12:28:22.827: DEBUG/dalvikvm(67): GC_EXPLICIT freed 3877 objects / 241128 bytes in 452ms 02-16 12:28:22.979: INFO/installd(35): unlink /data/dalvik-cache/data@[email protected]@classes.dex 02-16 12:28:23.277: DEBUG/AndroidRuntime(1019): Shutting down VM 02-16 12:28:23.307: DEBUG/dalvikvm(1019): Debugger has detached; object registry had 1 entries 02-16 12:28:23.328: INFO/AndroidRuntime(1019): NOTE: attach of thread 'Binder Thread #3' failed 02-16 12:28:24.989: DEBUG/AndroidRuntime(1032): >>>>>>>>>>>>>> AndroidRuntime START <<<<<<<<<<<<<< 02-16 12:28:24.989: DEBUG/AndroidRuntime(1032): CheckJNI is ON 02-16 12:28:25.888: DEBUG/AndroidRuntime(1032): --- registering native functions --- 02-16 12:28:28.588: INFO/ActivityManager(67): Starting activity: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10000000 cmp=com.example.userpage/.UserPage } 02-16 12:28:28.888: DEBUG/AndroidRuntime(1032): Shutting down VM 02-16 12:28:28.997: DEBUG/dalvikvm(1032): Debugger has detached; object registry had 1 entries 02-16 12:28:29.038: INFO/AndroidRuntime(1032): NOTE: attach of thread 'Binder Thread #3' failed 02-16 12:28:30.417: INFO/ActivityManager(67): Start proc com.example.userpage for activity com.example.userpage/.UserPage: pid=1039 uid=10036 gids={} 02-16 12:28:32.588: DEBUG/AndroidRuntime(1039): Shutting down VM 02-16 12:28:32.598: WARN/dalvikvm(1039): threadid=1: thread exiting with uncaught exception (group=0x4001d800) 02-16 12:28:32.648: ERROR/AndroidRuntime(1039): FATAL EXCEPTION: main 02-16 12:28:32.648: ERROR/AndroidRuntime(1039): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.userpage/com.example.userpage.UserPage}: java.lang.ClassCastException: android.widget.TextView 02-16 12:28:32.648: ERROR/AndroidRuntime(1039): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663) 02-16 12:28:32.648: ERROR/AndroidRuntime(1039): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) 02-16 12:28:32.648: ERROR/AndroidRuntime(1039): at android.app.ActivityThread.access$2300(ActivityThread.java:125) 02-16 12:28:32.648: ERROR/AndroidRuntime(1039): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033) 02-16 12:28:32.648: ERROR/AndroidRuntime(1039): at android.os.Handler.dispatchMessage(Handler.java:99) 02-16 12:28:32.648: ERROR/AndroidRuntime(1039): at android.os.Looper.loop(Looper.java:123) 02-16 12:28:32.648: ERROR/AndroidRuntime(1039): at android.app.ActivityThread.main(ActivityThread.java:4627) 02-16 12:28:32.648: ERROR/AndroidRuntime(1039): at java.lang.reflect.Method.invokeNative(Native Method) 02-16 12:28:32.648: ERROR/AndroidRuntime(1039): at java.lang.reflect.Method.invoke(Method.java:521) 02-16 12:28:32.648: ERROR/AndroidRuntime(1039): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 02-16 12:28:32.648: ERROR/AndroidRuntime(1039): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 02-16 12:28:32.648: ERROR/AndroidRuntime(1039): at dalvik.system.NativeStart.main(Native Method) 02-16 12:28:32.648: ERROR/AndroidRuntime(1039): Caused by: java.lang.ClassCastException: android.widget.TextView 02-16 12:28:32.648: ERROR/AndroidRuntime(1039): at com.example.userpage.UserPage.onCreate(UserPage.java:34) 02-16 12:28:32.648: ERROR/AndroidRuntime(1039): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 02-16 12:28:32.648: ERROR/AndroidRuntime(1039): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627) 02-16 12:28:32.648: ERROR/AndroidRuntime(1039): ... 11 more 02-16 12:28:32.698: WARN/ActivityManager(67): Force finishing activity com.example.userpage/.UserPage 02-16 12:28:32.967: DEBUG/dalvikvm(292): GC_EXPLICIT freed 46 objects / 2240 bytes in 6840ms 02-16 12:28:33.247: WARN/ActivityManager(67): Activity pause timeout for HistoryRecord{43ee7b70 com.example.userpage/.UserPage} 02-16 12:28:36.947: INFO/Process(1039): Sending signal. PID: 1039 SIG: 9 02-16 12:28:37.017: INFO/ActivityManager(67): Process com.example.userpage (pid 1039) has died. 02-16 12:28:37.128: WARN/InputManagerService(67): Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@43e872f8 02-16 12:28:42.087: DEBUG/dalvikvm(176): GC_EXPLICIT freed 156 objects / 11488 bytes in 145ms 02-16 12:28:45.391: WARN/ActivityManager(67): Activity destroy timeout for HistoryRecord{43ee7b70 com.example.userpage/.UserPage} 02-16 12:28:47.177: DEBUG/SntpClient(67): request time failed: java.net.SocketException: Address family not supported by protocol

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• Postgres cannot connect to server

  - by user1408935

  Super stumped by why Postgres isn't working on a new app I just started. I've got it working for one app already. I'm using postgres.app, and it's running. I started a new app with rails new depot -d postgresql and then I went into the database.yml file and changed username to my $USER (which is what it is for the other app, which is working). So now my database.yml file has this development section: development: adapter: postgresql encoding: unicode database: depot_development pool: 5 username: <username> password: But when I run "rake db:create" or "rake db:create:all" I still got this error (in full, cause I don't know what's relevant): Couldn't create database for {"adapter"=>"postgresql", "encoding"=>"unicode", "database"=>"depot_development", "pool"=>5, "username"=>"<username>", "password"=>nil} could not connect to server: Permission denied Is the server running locally and accepting connections on Unix domain socket "/var/pgsql_socket/.s.PGSQL.5432"? /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/postgresql_adapter.rb:1213:in `initialize' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/postgresql_adapter.rb:1213:in `new' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/postgresql_adapter.rb:1213:in `connect' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/postgresql_adapter.rb:329:in `initialize' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/postgresql_adapter.rb:28:in `new' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/postgresql_adapter.rb:28:in `postgresql_connection' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:309:in `new_connection' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:319:in `checkout_new_connection' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:241:in `block (2 levels) in checkout' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:236:in `loop' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:236:in `block in checkout' /Users/<username>/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:233:in `checkout' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:96:in `block in connection' /Users/<username>/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:95:in `connection' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:404:in `retrieve_connection' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_specification.rb:170:in `retrieve_connection' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_specification.rb:144:in `connection' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/railties/databases.rake:107:in `rescue in create_database' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/railties/databases.rake:51:in `create_database' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/railties/databases.rake:40:in `block (3 levels) in <top (required)>' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/railties/databases.rake:40:in `each' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.8/lib/active_record/railties/databases.rake:40:in `block (2 levels) in <top (required)>' /Users/<username>/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `call' /Users/<username>/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `block in execute' /Users/<username>/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `each' /Users/<username>/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `execute' /Users/<username>/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/task.rb:158:in `block in invoke_with_call_chain' /Users/<username>/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize' /Users/<username>/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/task.rb:151:in `invoke_with_call_chain' /Users/<username>/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/task.rb:144:in `invoke' /Users/<username>/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:116:in `invoke_task' /Users/<username>/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block (2 levels) in top_level' /Users/<username>/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `each' /Users/<username>/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block in top_level' /Users/<username>/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling' /Users/<username>/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:88:in `top_level' /Users/<username>/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:66:in `block in run' /Users/<username>/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling' /Users/<username>/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:63:in `run' /Users/<username>/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/bin/rake:33:in `<top (required)>' /Users/<username>/.rvm/gems/ruby-1.9.3-p194@global/bin/rake:19:in `load' /Users/<username>/.rvm/gems/ruby-1.9.3-p194@global/bin/rake:19:in `<main>' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/bin/ruby_noexec_wrapper:14:in `eval' /Users/<username>/.rvm/gems/ruby-1.9.3-p194/bin/ruby_noexec_wrapper:14:in `<main>' Couldn't create database for {"adapter"=>"postgresql", "encoding"=>"unicode", "database"=>"depot_test", "pool"=>5, "username"=>"<username>", "password"=>nil} I have tried createdb depot_development I have tried going into the psql environment and listing users (which included my username among them). In the same psql environment, I tried CREATE DATABASE depot; I've made sure that the pg gem is installed with bundle install, I've run "pg_ctl start", to which I got this response: pg_ctl: no database directory specified and environment variable PGDATA unset I ran "ps aux | grep postgres" to make sure postgres was running, to which I got this in return (which looks like it's doing OK, right?): <username> 10390 0.4 0.0 2425480 180 s000 R+ 6:15PM 0:00.00 grep postgres <username> 2907 0.0 0.0 2441604 464 ?? Ss 6:17PM 0:02.31 postgres: stats collector process <username> 2906 0.0 0.0 2445520 1664 ?? Ss 6:17PM 0:02.33 postgres: autovacuum launcher process <username> 2905 0.0 0.0 2445388 600 ?? Ss 6:17PM 0:09.25 postgres: wal writer process <username> 2904 0.0 0.0 2445388 1252 ?? Ss 6:17PM 0:12.08 postgres: writer process <username> 2902 0.0 0.0 2445388 3688 ?? S 6:17PM 0:00.54 /Applications/Postgres.app/Contents/MacOS/bin/postgres -D /Users/<username>/Library/Application Support/Postgres/var -p5432 The short of it, is I've been troubleshooting for a WHILE and have NO idea what's wrong. Any ideas? I'd really appreciate it, cause I'm pretty new to Rails, and this is a pretty disheartening roadblock. Thanks! EDIT -- Per request, posting the successful database.yml . It seems the difference is the inclusion of a password: development: adapter: postgresql encoding: unicode database: *******_development pool: 5 username: ******* password: ******* EDIT2 -- When I add a password to the .yml file, then run rake db:create again, I get this error. rake aborted! No Rakefile found (looking for: rakefile, Rakefile, rakefile.rb, Rakefile.rb)

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• javax.validation.ConstraintViolationException: validation failed for classes during update time for groups

  - by Tim

  Hello all! I have a Java / Spring MVC 3 application, using Hibernate and a MySQL database. In my controller, I have this source code: Set<ConstraintViolation<Person>> failures = validator.validate(p); if (failures.isEmpty()) { Project project = this.projectService.findProjectById(projectid); Person newPerson = this.personService.addPerson(p); Set<Person> persons = this.personService.getAllPersonsByProjectId(projectid); persons.add(newPerson); project.setPersons(persons); Set<ConstraintViolation<Project>> failures1 = validator.validate(project); if (!failures1.isEmpty()) { System.out.println("ERROR"); } else { System.out.println("NO ERROR"); } this.projectService.updateProject(project); return Collections.singletonMap("person", newPerson); } Project and Person are a many-to-many relation annotated with @manytomany and Project is the mapping owner. The new Person is added, but on the line with this.projectService.updateProject(project); I get an error. What it does it this in a Dao Hibernate implementation: public void updateProject(Project p) { SessionFactory sessionFactory = HibernateUtil.getSessionFactory(); Session sess = sessionFactory.getCurrentSession(); Transaction tx = sess.beginTransaction(); sess.update(p); tx.commit(); } It failed on the line tx.commit();. My check with if (!failures1.isEmpty()) { tell me that there are nor errors in my project. So what's wrong here? And why there is a validation of my project? I did not call a validation method... so why is there a org.hibernate.cfg.beanvalidation.BeanValidationEventListener.validate()? I hope, someone can help me how to fix this! Best Regards, Tim. Here the full error stack trace: 13.01.2011 00:06:36 org.apache.catalina.core.ApplicationDispatcher invoke SERVE: Servlet.service() for servlet project3 threw exception javax.validation.ConstraintViolationException: validation failed for classes [com.mydomain.myproject.domain.Person] during update time for groups [javax.validation.groups.Default, ] at org.hibernate.cfg.beanvalidation.BeanValidationEventListener.validate(BeanValidationEventListener.java:155) at org.hibernate.cfg.beanvalidation.BeanValidationEventListener.onPreUpdate(BeanValidationEventListener.java:102) at org.hibernate.action.EntityUpdateAction.preUpdate(EntityUpdateAction.java:235) at org.hibernate.action.EntityUpdateAction.execute(EntityUpdateAction.java:86) at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:273) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:265) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:185) at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321) at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51) at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1216) at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:383) at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:133) at com.mydomain.myproject.dao.impl.ProjectDaoImplHibernate.updateProject(ProjectDaoImplHibernate.java:44) at com.mydomain.myproject.service.impl.ProjectServiceImpl.updateProject(ProjectServiceImpl.java:39) at com.mydomain.myproject.controller.ProjectPersonController.addPerson(ProjectPersonController.java:189) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:176) at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:426) at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:414) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:790) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:644) at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:560) at javax.servlet.http.HttpServlet.service(HttpServlet.java:637) at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646) at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:436) at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:374) at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:302) at org.tuckey.web.filters.urlrewrite.NormalRewrittenUrl.doRewrite(NormalRewrittenUrl.java:195) at org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:159) at org.tuckey.web.filters.urlrewrite.RuleChain.doRules(RuleChain.java:141) at org.tuckey.web.filters.urlrewrite.UrlRewriter.processRequest(UrlRewriter.java:90) at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:417) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) at java.lang.Thread.run(Thread.java:619) 13.01.2011 00:06:36 org.apache.catalina.core.StandardWrapperValve invoke SERVE: Servlet.service() for servlet default threw exception javax.validation.ConstraintViolationException: validation failed for classes [com.mydomain.myproject.domain.Person] during update time for groups [javax.validation.groups.Default, ] at org.hibernate.cfg.beanvalidation.BeanValidationEventListener.validate(BeanValidationEventListener.java:155) at org.hibernate.cfg.beanvalidation.BeanValidationEventListener.onPreUpdate(BeanValidationEventListener.java:102) at org.hibernate.action.EntityUpdateAction.preUpdate(EntityUpdateAction.java:235) at org.hibernate.action.EntityUpdateAction.execute(EntityUpdateAction.java:86) at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:273) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:265) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:185) at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321) at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51) at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1216) at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:383) at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:133) at com.mydomain.myproject.dao.impl.ProjectDaoImplHibernate.updateProject(ProjectDaoImplHibernate.java:44) at com.mydomain.myproject.service.impl.ProjectServiceImpl.updateProject(ProjectServiceImpl.java:39) at com.mydomain.myproject.controller.ProjectPersonController.addPerson(ProjectPersonController.java:189) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:176) at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:426) at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:414) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:790) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:644) at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:560) at javax.servlet.http.HttpServlet.service(HttpServlet.java:637) at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646) at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:436) at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:374) at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:302) at org.tuckey.web.filters.urlrewrite.NormalRewrittenUrl.doRewrite(NormalRewrittenUrl.java:195) at org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:159) at org.tuckey.web.filters.urlrewrite.RuleChain.doRules(RuleChain.java:141) at org.tuckey.web.filters.urlrewrite.UrlRewriter.processRequest(UrlRewriter.java:90) at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:417) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) at java.lang.Thread.run(Thread.java:619) UPDATE Before updating the Project where the error occurs, I add a person which have this annotated: @NotNull @Size(min = 1, max = 255) @Pattern(regexp="(?:[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*|\"(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21\\x23-\\x5b\\x5d-\\x7f]|\\\\[\\x01-\\x09\\x0b\\x0c\\x0e-\\x7f])*\")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-]*[a-z0-9]:(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21-\\x5a\\x53-\\x7f]|\\\\[\\x01-\\x09\\x0b\\x0c\\x0e-\\x7f])+)\\])", message="{my.email.error.message}") private String email; Without the @Pattern no error... So, what's wrong here? UPDATE-2: I use Hibernate 3.6.0.Final and I have these in my Maven pom.xml: <!-- JSR 303 with Hibernate Validator --> <dependency> <groupId>javax.validation</groupId> <artifactId>validation-api</artifactId> <version>1.0.0.GA</version> </dependency> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-validator</artifactId> <version>4.1.0.Final</version> </dependency>

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• My App crashes when launched on my Iphone

  - by Miky Mike

  hi guys, I have a problem here : my app crashed on my Iphone (JB) though Xcode doesn't complain about anything. The app works fine on the simulator though. However, there is this in the device logs : Thread 0 Crashed: 0 libSystem.B.dylib 0x00078ac8 kill + 8 1 libSystem.B.dylib 0x00078ab8 kill + 4 2 libSystem.B.dylib 0x00078aaa raise + 10 3 libSystem.B.dylib 0x0008d03a abort + 50 4 libstdc++.6.dylib 0x00044a20 __gnu_cxx::__verbose_terminate_handler() + 376 5 libobjc.A.dylib 0x00005958 _objc_terminate + 104 6 libstdc++.6.dylib 0x00042df2 _cxxabiv1::_terminate(void (*)()) + 46 7 libstdc++.6.dylib 0x00042e46 std::terminate() + 10 8 libstdc++.6.dylib 0x00042f16 __cxa_throw + 78 9 libobjc.A.dylib 0x00004838 objc_exception_throw + 64 10 CoreFoundation 0x0009fd0e +[NSException raise:format:arguments:] + 62 11 CoreFoundation 0x0009fd48 +[NSException raise:format:] + 28 12 Foundation 0x000125d8 -[NSURL(NSURL) initFileURLWithPath:] + 64 13 Foundation 0x000371e0 +[NSURL(NSURL) fileURLWithPath:] + 24 14 TheLearningMachine 0x00002d08 0x1000 + 7432 15 TheLearningMachine 0x00002e8c 0x1000 + 7820 16 TheLearningMachine 0x00002be4 0x1000 + 7140 17 TheLearningMachine 0x000029b6 0x1000 + 6582 18 UIKit 0x0000e47a -[UIApplication _callInitializationDelegatesForURL:payload:suspended:] + 766 19 UIKit 0x000049e0 -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 200 20 UIKit 0x0005dfd6 -[UIApplication handleEvent:withNewEvent:] + 1390 21 UIKit 0x0005d8fa -[UIApplication sendEvent:] + 38 22 UIKit 0x0005d330 _UIApplicationHandleEvent + 5104 23 GraphicsServices 0x00005044 PurpleEventCallback + 660 24 CoreFoundation 0x00034cdc __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION + 20 25 CoreFoundation 0x00034ca0 __CFRunLoopDoSource1 + 160 26 CoreFoundation 0x00027566 __CFRunLoopRun + 514 27 CoreFoundation 0x00027270 CFRunLoopRunSpecific + 224 28 CoreFoundation 0x00027178 CFRunLoopRunInMode + 52 29 UIKit 0x000040fc -[UIApplication _run] + 364 30 UIKit 0x00002128 UIApplicationMain + 664 31 TheLearningMachine 0x00002948 0x1000 + 6472 32 TheLearningMachine 0x000028fc 0x1000 + 6396 Thread 1: 0 libSystem.B.dylib 0x0002d330 kevent + 24 1 libSystem.B.dylib 0x000d6b6c _dispatch_mgr_invoke + 88 2 libSystem.B.dylib 0x000d65bc _dispatch_queue_invoke + 96 3 libSystem.B.dylib 0x000d675c _dispatch_worker_thread2 + 120 4 libSystem.B.dylib 0x0007a67a _pthread_wqthread + 258 5 libSystem.B.dylib 0x00073190 start_wqthread + 0 Thread 2: 0 libSystem.B.dylib 0x0007b19c __workq_kernreturn + 8 1 libSystem.B.dylib 0x0007a790 _pthread_wqthread + 536 2 libSystem.B.dylib 0x00073190 start_wqthread + 0 Thread 3: 0 libSystem.B.dylib 0x00000c98 mach_msg_trap + 20 1 libSystem.B.dylib 0x00002d64 mach_msg + 44 2 CoreFoundation 0x00027c38 __CFRunLoopServiceMachPort + 88 3 CoreFoundation 0x000274c2 __CFRunLoopRun + 350 4 CoreFoundation 0x00027270 CFRunLoopRunSpecific + 224 5 CoreFoundation 0x00027178 CFRunLoopRunInMode + 52 6 WebCore 0x000024e2 RunWebThread(void*) + 362 7 libSystem.B.dylib 0x0007a27e _pthread_start + 242 8 libSystem.B.dylib 0x0006f2a8 thread_start + 0 Thread 0 crashed with ARM Thread State: r0: 0x00000000 r1: 0x00000000 r2: 0x00000001 r3: 0x3e0862b4 r4: 0x00000006 r5: 0x0015a2ec r6: 0x2fffe090 r7: 0x2fffe0a0 r8: 0x3e1a378c r9: 0x00000065 r10: 0x33028e5a r11: 0x3e1ab89c ip: 0x00000025 sp: 0x2fffe0a0 lr: 0x30277abf pc: 0x30277ac8 cpsr: 0x000f0010 Any idea what the problem can be ? I've already spent my whole day on that, but... I'm stuck. Thanks in advance... Miky Mike Ok, Here is more then from the console, I get this : This GDB was configured as "--host=i386-apple-darwin --target=arm-apple-darwin".tty /dev/ttys002 Loading program into debugger… Program loaded. target remote-mobile /tmp/.XcodeGDBRemote-17280-65 Switching to remote-macosx protocol mem 0x1000 0x3fffffff cache mem 0x40000000 0xffffffff none mem 0x00000000 0x0fff none run Running… Error launching remote program: failed to get the task for process 456. Error launching remote program: failed to get the task for process 456. The program being debugged is not being run. The program being debugged is not being run. [Session started at 2010-12-23 20:33:33 +0100.] GNU gdb 6.3.50-20050815 (Apple version gdb-1472) (Thu Aug 5 05:54:10 UTC 2010) Copyright 2004 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "--host=i386-apple-darwin --target=arm-apple-darwin".tty /dev/ttys004 Loading program into debugger… Program loaded. target remote-mobile /tmp/.XcodeGDBRemote-17280-72 Switching to remote-macosx protocol mem 0x1000 0x3fffffff cache mem 0x40000000 0xffffffff none mem 0x00000000 0x0fff none run Running… Error launching remote program: failed to get the task for process 508. Error launching remote program: failed to get the task for process 508. The program being debugged is not being run. The program being debugged is not being run. And here is the code page that calls the URL import "TheLearningMachineAppDelegate.h" import "RootViewController.h" @implementation TheLearningMachineAppDelegate @synthesize window; @synthesize navigationController; pragma mark - pragma mark Application lifecycle (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { RootViewController *rootViewController = (RootViewController *)[navigationController topViewController]; rootViewController.managedObjectContext = self.managedObjectContext; [window addSubview:[navigationController view]]; [window makeKeyAndVisible]; return YES; } (void)applicationWillResignActive:(UIApplication )application { / Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state. Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game. */ } (void)applicationDidEnterBackground:(UIApplication *)application { [self saveContext]; } (void)applicationWillEnterForeground:(UIApplication )application { / Called as part of the transition from the background to the inactive state: here you can undo many of the changes made on entering the background. */ } (void)applicationDidBecomeActive:(UIApplication )application { / Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface. */ } // Method that saves the managed object context before the application terminates. (void)applicationWillTerminate:(UIApplication *)application { [self saveContext]; } (void)saveContext { NSError *error = nil; if (managedObjectContext != nil) { if ([managedObjectContext hasChanges] && ![managedObjectContext save:&error]) { NSLog(@"Unresolved error %@, %@", error, [error userInfo]); abort(); //Replace this implementation with code to handle the error appropriately. //abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button. } } } pragma mark - pragma mark Core Data stack // Returns the managed object context for the application. (NSManagedObjectContext *)managedObjectContext { if (managedObjectContext != nil) { return managedObjectContext; } NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator]; if (coordinator != nil) { managedObjectContext = [[NSManagedObjectContext alloc] init]; [managedObjectContext setPersistentStoreCoordinator:coordinator]; } return managedObjectContext; } // Returns the managed object model for the application. (NSManagedObjectModel *)managedObjectModel { if (managedObjectModel != nil) { return managedObjectModel; } NSString *modelPath = [[NSBundle mainBundle] pathForResource:@"TheLearningMachine" ofType:@"momd"]; NSURL *modelURL = [NSURL fileURLWithPath:modelPath]; managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL]; return managedObjectModel; } pragma mark - pragma mark Application's Documents directory // Returns the path to the application's Documents directory. - (NSString *)applicationDocumentsDirectory { return [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject]; } // Returns the persistent store coordinator for the application. - (NSPersistentStoreCoordinator *)persistentStoreCoordinator { if (persistentStoreCoordinator != nil) { return persistentStoreCoordinator; } NSURL *storeURL = [NSURL fileURLWithPath: [[self applicationDocumentsDirectory] stringByAppendingPathComponent: @"TheLearningMachine.sqlite"]]; NSError *error = nil; persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]]; if (![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error]) { NSLog(@"Unresolved error %@, %@", error, [error userInfo]); abort(); } return persistentStoreCoordinator; } pragma mark - pragma mark Memory management (void)applicationDidReceiveMemoryWarning:(UIApplication )application { / Free up as much memory as possible by purging cached data objects that can be recreated (or reloaded from disk) later. */ } (void)dealloc { [managedObjectContext release]; [managedObjectModel release]; [persistentStoreCoordinator release]; [window release]; [super dealloc]; } @end

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• Use a single freemarker template to display tables of arbitrary pojos

  - by Kevin Pauli

  Attention advanced Freemarker gurus: I want to use a single freemarker template to be able to output tables of arbitrary pojos, with the columns to display defined separately than the data. The problem is that I can't figure out how to get a handle to a function on a pojo at runtime, and then have freemarker invoke that function (lambda style). From skimming the docs it seems that Freemarker supports functional programming, but I can't seem to forumulate the proper incantation. I whipped up a simplistic concrete example. Let's say I have two lists: a list of people with a firstName and lastName, and a list of cars with a make and model. would like to output these two tables: <table> <tr> <th>firstName</th> <th>lastName</th> </tr> <tr> <td>Joe</td> <td>Blow</d> </tr> <tr> <td>Mary</td> <td>Jane</d> </tr> </table> and <table> <tr> <th>make</th> <th>model</th> </tr> <tr> <td>Toyota</td> <td>Tundra</d> </tr> <tr> <td>Honda</td> <td>Odyssey</d> </tr> </table> But I want to use the same template, since this is part of a framework that has to deal with dozens of different pojo types. Given the following code: public class FreemarkerTest { public static class Table { private final List<Column> columns = new ArrayList<Column>(); public Table(Column[] columns) { this.columns.addAll(Arrays.asList(columns)); } public List<Column> getColumns() { return columns; } } public static class Column { private final String name; public Column(String name) { this.name = name; } public String getName() { return name; } } public static class Person { private final String firstName; private final String lastName; public Person(String firstName, String lastName) { this.firstName = firstName; this.lastName = lastName; } public String getFirstName() { return firstName; } public String getLastName() { return lastName; } } public static class Car { String make; String model; public Car(String make, String model) { this.make = make; this.model = model; } public String getMake() { return make; } public String getModel() { return model; } } public static void main(String[] args) throws Exception { final Table personTableDefinition = new Table(new Column[] { new Column("firstName"), new Column("lastName") }); final List<Person> people = Arrays.asList(new Person[] { new Person("Joe", "Blow"), new Person("Mary", "Jane") }); final Table carTable = new Table(new Column[] { new Column("make"), new Column("model") }); final List<Car> cars = Arrays.asList(new Car[] { new Car("Toyota", "Tundra"), new Car("Honda", "Odyssey") }); final Configuration cfg = new Configuration(); cfg.setClassForTemplateLoading(FreemarkerTest.class, ""); cfg.setObjectWrapper(new DefaultObjectWrapper()); final Template template = cfg.getTemplate("test.ftl"); process(template, personTableDefinition, people); process(template, carTable, cars); } private static void process(Template template, Table tableDefinition, List<? extends Object> data) throws Exception { final Map<String, Object> dataMap = new HashMap<String, Object>(); dataMap.put("tableDefinition", tableDefinition); dataMap.put("data", data); final Writer out = new OutputStreamWriter(System.out); template.process(dataMap, out); out.flush(); } } All the above is a given for this problem. So here is the template I have been hacking on. Note the comment where I am having trouble. <table> <tr> <#list tableDefinition.columns as col> <th>${col.name}</th> </#list> </tr> <#list data as pojo> <tr> <#list tableDefinition.columns as col> <td><#-- what goes here? --></td> </#list> </tr> </#list> </table> So col.name has the name of the property I want to access from the pojo. I have tried a few things, such as pojo.col.name and <#assign property = col.name/> ${pojo.property} but of course these don't work, I just included them to help convey my intent. I am looking for a way to get a handle to a function and have freemarker invoke it, or perhaps some kind of "evaluate" feature that can take an arbitrary expression as a string and evaluate it at runtime.

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• delete function and upload

  - by Jesper Petersen

  it must be said that I download the database and all my function is in class. That's how I was incredible pleased function and think they are nice .. That's how I'm going to build a gallery where the id of the upload to the site if it fits with the id_session is log in page, you have the option to delete it. and so it must just go back to / latest pictures / when it delete it from the folder and database. but it comes up with an error as you can see here; Fatal error: Call to a member function bind_param () on a non-object in / home / jesperbo / public_html / mebe.dk / function / function.php on line 411 It is such that I am also in the process of building an upload system where the underlying database and make it smaller after what I have now set it and when it did the 2 things must send me back to / latest-images / but it do not reach the only available picture up on the server and do it with the picture but it will not go back in some way at all. So to / latest-images / Where wrong with it to delete, etc. I lie just here, $stm1->bind_param('i', $id_gallery); function img_slet_indhold(){ if($_SESSION["logged_in"] = true && $_SESSION["rank"] == '1' || $_SESSION["rank"] == 2) { if($stmt = $this->mysqli->prepare('SELECT `title` FROM `gallery` WHERE `id_gallery` = ?')) { $stm1->bind_param('i', $id_gallery); $id_gallery = $_GET["id_gallery"]; $stm1->execute(); $stm1->store_result(); $stm1->bind_result($title); $UploadDir = "/gallery/"; //ligger i toppen af documentet, evt som en define if($stm1->fetch()) { $tmpfile = $UploadDir . "" . $title; if(file_exists($tmpfile)) { unlink($tmpfile); } $tmpfile = $UploadDir . "lille/" . $title; if(file_exists($tmpfile)) { unlink($tmpfile); } $tmpfile = $UploadDir . "store/" . $title; if(file_exists($tmpfile)) { unlink($tmpfile); } } $stm1->close(); } else { /* Der er opstået en fejl */ echo 'Der opstod en fejl i erklæringen: ' . $mysqli->error; } } if($stmt = $this->mysqli->prepare('DELETE FROM `gallery` WHERE `id_gallery` = ?' )) { $stmt->bind_param('i', $id); $id = $_GET["id_gallery"]; $stmt->execute(); header('Location: /nyeste-billeder/'); $stmt->close(); } else { /* Der er opstået en fejl */ echo 'Der opstod en fejl i erklæringen: ' . $mysqli->error; } } So into the file as it should delete from, I have chosen to do so here; <?php session_start(); require_once ("function/function.php"); $mebe = new mebe; $db = $mebe->db_c(); error_reporting(E_ERROR); $img_slet_indhold = $mebe->img_slet_indhold(); ?> So when I upload image to folder and database, and just after can be returned when uploading function img_indhold(){ if($_SESSION["logged_in"] = true && $_SESSION["rank"] == '1' || $_SESSION["rank"] == 2) { include "function/class.upload.php"; $handle = new Upload($_FILES["filename"]); if($handle->uploaded) { //lidt mere store billeder $handle->image_resize = true; $handle->image_ratio_y = true; $handle->image_x = 220; $handle->Process("gallery/store"); //til profil billede lign.. $handle->image_resize = true; $handle->image_ratio_crop = true; $handle->image_y = 115; $handle->image_x = 100; $handle->Process("gallery"); //til profil billede lign.. $handle->image_resize = true; $handle->image_ratio_crop = true; $handle->image_y = 75; $handle->image_x = 75; $handle->Process("gallery/lille"); $pb = $handle->file_dst_name; } if($stmt = $this->mysqli->prepare('INSERT INTO `gallery` (`title`, `id_bruger`) VALUES (?, ?)')) { $stmt->bind_param('si', $title, $id_bruger); $title = $pb; $id_bruger = $_SESSION["id"]; $stmt->execute(); header('Location: /nyeste-billeder/'); $stmt->close(); } } } So when I call it on the page when it is required to do so do it like this; <?php session_start(); require_once ("function/function.php"); $mebe = new mebe; $db = $mebe->db_c(); error_reporting(E_ERROR); $img_slet_indhold = $mebe->img_slet_indhold(); ?> it is here as to when I will upload to the site and show gallery / pictures on the page function vise_img(){ if ($stmt = $this->mysqli->prepare('SELECT `id_gallery`, `title`, `id_bruger` FROM `gallery` ORDER BY `gallery`.`id_gallery` DESC')) { $stmt->execute(); $stmt->store_result(); $stmt->bind_result($id_gallery, $title, $id_bruger); while ($stmt->fetch()) { echo "<div id=\"gallery_box\">"; echo "<a href=\"/profil/$id_bruger/\"><img src=\"/gallery/$title\" alt=\"\" height=\"115\" width=\"100\" border=\"0\"></a>"; if($_SESSION["logged_in"]) { if($id_bruger == $_SESSION["id"]) { echo "<ul>"; echo "<li><a href=\"/nyeste-billeder-slet/$id_gallery/\">Slet</a></li>"; echo "</ul>"; } } echo "</div>"; } /* Luk statement */ $stmt->close(); } else { /* Der er opstået en fejl */ echo 'Der opstod en fejl i erklæringen: ' . $mysqli->error; } } function upload_img(){ if($_SESSION["logged_in"] = true && $_SESSION["rank"] == '1' || $_SESSION["rank"] == 2) { ?> <form name="opslag" method="post" action="/nyeste-ok/" enctype="multipart/form-data"> <input type="file" name="filename" id="filename" onchange="checkFileExt(this)"> <input name="upload" value="Upload" id="background_indhold" onclick="return check()" type="submit"> </form> <?php } elseif ($_SESSION["logged_in"] != true && $_SESSION["rank"] != '1' || $_SESSION["rank"] != 2) { echo "<p>Du har ingen mulighed for at upload billeder på siden</p>"; } } Really hope you are able to help me further!

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• Parallelism in .NET – Part 7, Some Differences between PLINQ and LINQ to Objects

  - by Reed

  In my previous post on Declarative Data Parallelism, I mentioned that PLINQ extends LINQ to Objects to support parallel operations.  Although nearly all of the same operations are supported, there are some differences between PLINQ and LINQ to Objects.  By introducing Parallelism to our declarative model, we add some extra complexity.  This, in turn, adds some extra requirements that must be addressed. In order to illustrate the main differences, and why they exist, let’s begin by discussing some differences in how the two technologies operate, and look at the underlying types involved in LINQ to Objects and PLINQ . LINQ to Objects is mainly built upon a single class: Enumerable.  The Enumerable class is a static class that defines a large set of extension methods, nearly all of which work upon an IEnumerable<T>.  Many of these methods return a new IEnumerable<T>, allowing the methods to be chained together into a fluent style interface.  This is what allows us to write statements that chain together, and lead to the nice declarative programming model of LINQ: double min = collection .Where(item => item.SomeProperty > 6 && item.SomeProperty < 24) .Min(item => item.PerformComputation()); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Other LINQ variants work in a similar fashion.  For example, most data-oriented LINQ providers are built upon an implementation of IQueryable<T>, which allows the database provider to turn a LINQ statement into an underlying SQL query, to be performed directly on the remote database. PLINQ is similar, but instead of being built upon the Enumerable class, most of PLINQ is built upon a new static class: ParallelEnumerable.  When using PLINQ, you typically begin with any collection which implements IEnumerable<T>, and convert it to a new type using an extension method defined on ParallelEnumerable: AsParallel().  This method takes any IEnumerable<T>, and converts it into a ParallelQuery<T>, the core class for PLINQ.  There is a similar ParallelQuery class for working with non-generic IEnumerable implementations. This brings us to our first subtle, but important difference between PLINQ and LINQ – PLINQ always works upon specific types, which must be explicitly created. Typically, the type you’ll use with PLINQ is ParallelQuery<T>, but it can sometimes be a ParallelQuery or an OrderedParallelQuery<T>.  Instead of dealing with an interface, implemented by an unknown class, we’re dealing with a specific class type.  This works seamlessly from a usage standpoint – ParallelQuery<T> implements IEnumerable<T>, so you can always “switch back” to an IEnumerable<T>.  The difference only arises at the beginning of our parallelization.  When we’re using LINQ, and we want to process a normal collection via PLINQ, we need to explicitly convert the collection into a ParallelQuery<T> by calling AsParallel().  There is an important consideration here – AsParallel() does not need to be called on your specific collection, but rather any IEnumerable<T>.  This allows you to place it anywhere in the chain of methods involved in a LINQ statement, not just at the beginning.  This can be useful if you have an operation which will not parallelize well or is not thread safe.  For example, the following is perfectly valid, and similar to our previous examples: double min = collection .AsParallel() .Select(item => item.SomeOperation()) .Where(item => item.SomeProperty > 6 && item.SomeProperty < 24) .Min(item => item.PerformComputation()); However, if SomeOperation() is not thread safe, we could just as easily do: double min = collection .Select(item => item.SomeOperation()) .AsParallel() .Where(item => item.SomeProperty > 6 && item.SomeProperty < 24) .Min(item => item.PerformComputation()); In this case, we’re using standard LINQ to Objects for the Select(…) method, then converting the results of that map routine to a ParallelQuery<T>, and processing our filter (the Where method) and our aggregation (the Min method) in parallel. PLINQ also provides us with a way to convert a ParallelQuery<T> back into a standard IEnumerable<T>, forcing sequential processing via standard LINQ to Objects.  If SomeOperation() was thread-safe, but PerformComputation() was not thread-safe, we would need to handle this by using the AsEnumerable() method: double min = collection .AsParallel() .Select(item => item.SomeOperation()) .Where(item => item.SomeProperty > 6 && item.SomeProperty < 24) .AsEnumerable() .Min(item => item.PerformComputation()); Here, we’re converting our collection into a ParallelQuery<T>, doing our map operation (the Select(…) method) and our filtering in parallel, then converting the collection back into a standard IEnumerable<T>, which causes our aggregation via Min() to be performed sequentially. This could also be written as two statements, as well, which would allow us to use the language integrated syntax for the first portion: var tempCollection = from item in collection.AsParallel() let e = item.SomeOperation() where (e.SomeProperty > 6 && e.SomeProperty < 24) select e; double min = tempCollection.AsEnumerable().Min(item => item.PerformComputation()); This allows us to use the standard LINQ style language integrated query syntax, but control whether it’s performed in parallel or serial by adding AsParallel() and AsEnumerable() appropriately. The second important difference between PLINQ and LINQ deals with order preservation.  PLINQ, by default, does not preserve the order of of source collection. This is by design.  In order to process a collection in parallel, the system needs to naturally deal with multiple elements at the same time.  Maintaining the original ordering of the sequence adds overhead, which is, in many cases, unnecessary.  Therefore, by default, the system is allowed to completely change the order of your sequence during processing.  If you are doing a standard query operation, this is usually not an issue.  However, there are times when keeping a specific ordering in place is important.  If this is required, you can explicitly request the ordering be preserved throughout all operations done on a ParallelQuery<T> by using the AsOrdered() extension method.  This will cause our sequence ordering to be preserved. For example, suppose we wanted to take a collection, perform an expensive operation which converts it to a new type, and display the first 100 elements.  In LINQ to Objects, our code might look something like: // Using IEnumerable<SourceClass> collection IEnumerable<ResultClass> results = collection .Select(e => e.CreateResult()) .Take(100); If we just converted this to a parallel query naively, like so: IEnumerable<ResultClass> results = collection .AsParallel() .Select(e => e.CreateResult()) .Take(100); We could very easily get a very different, and non-reproducable, set of results, since the ordering of elements in the input collection is not preserved.  To get the same results as our original query, we need to use: IEnumerable<ResultClass> results = collection .AsParallel() .AsOrdered() .Select(e => e.CreateResult()) .Take(100); This requests that PLINQ process our sequence in a way that verifies that our resulting collection is ordered as if it were processed serially.  This will cause our query to run slower, since there is overhead involved in maintaining the ordering.  However, in this case, it is required, since the ordering is required for correctness. PLINQ is incredibly useful.  It allows us to easily take nearly any LINQ to Objects query and run it in parallel, using the same methods and syntax we’ve used previously.  There are some important differences in operation that must be considered, however – it is not a free pass to parallelize everything.  When using PLINQ in order to parallelize your routines declaratively, the same guideline I mentioned before still applies: Parallelization is something that should be handled with care and forethought, added by design, and not just introduced casually.

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• Parallelism in .NET – Part 2, Simple Imperative Data Parallelism

  - by Reed

  In my discussion of Decomposition of the problem space, I mentioned that Data Decomposition is often the simplest abstraction to use when trying to parallelize a routine.  If a problem can be decomposed based off the data, we will often want to use what MSDN refers to as Data Parallelism as our strategy for implementing our routine.  The Task Parallel Library in .NET 4 makes implementing Data Parallelism, for most cases, very simple. Data Parallelism is the main technique we use to parallelize a routine which can be decomposed based off data.  Data Parallelism refers to taking a single collection of data, and having a single operation be performed concurrently on elements in the collection.  One side note here: Data Parallelism is also sometimes referred to as the Loop Parallelism Pattern or Loop-level Parallelism.  In general, for this series, I will try to use the terminology used in the MSDN Documentation for the Task Parallel Library.  This should make it easier to investigate these topics in more detail. Once we’ve determined we have a problem that, potentially, can be decomposed based on data, implementation using Data Parallelism in the TPL is quite simple.  Let’s take our example from the Data Decomposition discussion – a simple contrast stretching filter.  Here, we have a collection of data (pixels), and we need to run a simple operation on each element of the pixel.  Once we know the minimum and maximum values, we most likely would have some simple code like the following: for (int row=0; row < pixelData.GetUpperBound(0); ++row) { for (int col=0; col < pixelData.GetUpperBound(1); ++col) { pixelData[row, col] = AdjustContrast(pixelData[row, col], minPixel, maxPixel); } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } This simple routine loops through a two dimensional array of pixelData, and calls the AdjustContrast routine on each pixel. As I mentioned, when you’re decomposing a problem space, most iteration statements are potentially candidates for data decomposition.  Here, we’re using two for loops – one looping through rows in the image, and a second nested loop iterating through the columns.  We then perform one, independent operation on each element based on those loop positions. This is a prime candidate – we have no shared data, no dependencies on anything but the pixel which we want to change.  Since we’re using a for loop, we can easily parallelize this using the Parallel.For method in the TPL: Parallel.For(0, pixelData.GetUpperBound(0), row => { for (int col=0; col < pixelData.GetUpperBound(1); ++col) { pixelData[row, col] = AdjustContrast(pixelData[row, col], minPixel, maxPixel); } }); Here, by simply changing our first for loop to a call to Parallel.For, we can parallelize this portion of our routine.  Parallel.For works, as do many methods in the TPL, by creating a delegate and using it as an argument to a method.  In this case, our for loop iteration block becomes a delegate creating via a lambda expression.  This lets you write code that, superficially, looks similar to the familiar for loop, but functions quite differently at runtime. We could easily do this to our second for loop as well, but that may not be a good idea.  There is a balance to be struck when writing parallel code.  We want to have enough work items to keep all of our processors busy, but the more we partition our data, the more overhead we introduce.  In this case, we have an image of data – most likely hundreds of pixels in both dimensions.  By just parallelizing our first loop, each row of pixels can be run as a single task.  With hundreds of rows of data, we are providing fine enough granularity to keep all of our processors busy. If we parallelize both loops, we’re potentially creating millions of independent tasks.  This introduces extra overhead with no extra gain, and will actually reduce our overall performance.  This leads to my first guideline when writing parallel code: Partition your problem into enough tasks to keep each processor busy throughout the operation, but not more than necessary to keep each processor busy. Also note that I parallelized the outer loop.  I could have just as easily partitioned the inner loop.  However, partitioning the inner loop would have led to many more discrete work items, each with a smaller amount of work (operate on one pixel instead of one row of pixels).  My second guideline when writing parallel code reflects this: Partition your problem in a way to place the most work possible into each task. This typically means, in practice, that you will want to parallelize the routine at the “highest” point possible in the routine, typically the outermost loop.  If you’re looking at parallelizing methods which call other methods, you’ll want to try to partition your work high up in the stack – as you get into lower level methods, the performance impact of parallelizing your routines may not overcome the overhead introduced. Parallel.For works great for situations where we know the number of elements we’re going to process in advance.  If we’re iterating through an IList<T> or an array, this is a typical approach.  However, there are other iteration statements common in C#.  In many situations, we’ll use foreach instead of a for loop.  This can be more understandable and easier to read, but also has the advantage of working with collections which only implement IEnumerable<T>, where we do not know the number of elements involved in advance. As an example, lets take the following situation.  Say we have a collection of Customers, and we want to iterate through each customer, check some information about the customer, and if a certain case is met, send an email to the customer and update our instance to reflect this change.  Normally, this might look something like: foreach(var customer in customers) { // Run some process that takes some time... DateTime lastContact = theStore.GetLastContact(customer); TimeSpan timeSinceContact = DateTime.Now - lastContact; // If it's been more than two weeks, send an email, and update... if (timeSinceContact.Days > 14) { theStore.EmailCustomer(customer); customer.LastEmailContact = DateTime.Now; } } Here, we’re doing a fair amount of work for each customer in our collection, but we don’t know how many customers exist.  If we assume that theStore.GetLastContact(customer) and theStore.EmailCustomer(customer) are both side-effect free, thread safe operations, we could parallelize this using Parallel.ForEach: Parallel.ForEach(customers, customer => { // Run some process that takes some time... DateTime lastContact = theStore.GetLastContact(customer); TimeSpan timeSinceContact = DateTime.Now - lastContact; // If it's been more than two weeks, send an email, and update... if (timeSinceContact.Days > 14) { theStore.EmailCustomer(customer); customer.LastEmailContact = DateTime.Now; } }); Just like Parallel.For, we rework our loop into a method call accepting a delegate created via a lambda expression.  This keeps our new code very similar to our original iteration statement, however, this will now execute in parallel.  The same guidelines apply with Parallel.ForEach as with Parallel.For. The other iteration statements, do and while, do not have direct equivalents in the Task Parallel Library.  These, however, are very easy to implement using Parallel.ForEach and the yield keyword. Most applications can benefit from implementing some form of Data Parallelism.  Iterating through collections and performing “work” is a very common pattern in nearly every application.  When the problem can be decomposed by data, we often can parallelize the workload by merely changing foreach statements to Parallel.ForEach method calls, and for loops to Parallel.For method calls.  Any time your program operates on a collection, and does a set of work on each item in the collection where that work is not dependent on other information, you very likely have an opportunity to parallelize your routine.

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• Node.js Adventure - When Node Flying in Wind

  - by Shaun

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

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• ERROR: Attempted to read or write protected memory. This is often an indication that other memory is corrupt

  - by SPSamL

  I get this error after having edited a few pages in SharePoint 2010. I have to do an IISReset on both front ends to get this to resolve. I don't know how to fix it or even what else to supply here, but please let me know as the resets now happen several times per day. Log Name: Application Source: ASP.NET 2.0.50727.0 Date: 1/26/2011 11:12:48 AM Event ID: 1309 Task Category: Web Event Level: Warning Keywords: Classic User: N/A Computer: PINTSPSFE02.samcstl.org Description: Event code: 3005 Event message: An unhandled exception has occurred. Event time: 1/26/2011 11:12:48 AM Event time (UTC): 1/26/2011 5:12:48 PM Event ID: c52fb336b7f147a3913fff3617a99d57 Event sequence: 4965 Event occurrence: 2178 Event detail code: 0 Application information: Application domain: /LM/W3SVC/1449762715/ROOT-2-129405348166941887 Trust level: WSS_Minimal Application Virtual Path: / Application Path: C:\inetpub\wwwroot\wss\VirtualDirectories\80\ Machine name: PINTSPSFE02 Process information: Process ID: 5928 Process name: w3wp.exe Account name: SAMC\MossAppPool Exception information: Exception type: AccessViolationException Exception message: Attempted to read or write protected memory. This is often an indication that other memory is corrupt. Request information: Request URL: http://mosscluster/Pages/Home.aspx Request path: /Pages/Home.aspx User host address: 10.3.60.26 User: SAMC\BARNMD Is authenticated: True Authentication Type: NTLM Thread account name: SAMC\MossAppPool Thread information: Thread ID: 110 Thread account name: SAMC\MossAppPool Is impersonating: False Stack trace: at Microsoft.Office.Server.ObjectCache.SPCache.MossObjectCache_Tracked.Delete(String key, Boolean recursive, DeletionReason reason) at Microsoft.Office.Server.ObjectCache.SPCache.MossObjectCache_Tracked.Get(String key) at Microsoft.Office.Server.ObjectCache.SPCache.Get(String objectTypeName, String id) at Microsoft.Office.Server.Administration.UserProfileServiceProxy.GetPartitionPropertiesCache(Guid applicationID) at Microsoft.Office.Server.Administration.UserProfileApplicationProxy.get_PartitionPropertiesCache() at Microsoft.Office.Server.Administration.UserProfileApplicationProxy.DataCache.get_PartitionProperties() at Microsoft.Office.Server.Administration.UserProfileApplicationProxy.GetMySitePortalUrl(SPUrlZone zone, Guid partitionID) at Microsoft.Office.Server.Administration.UserProfileApplicationProxy.GetMySitePortalUrl(SPUrlZone zone, SPServiceContext serviceContext) at Microsoft.Office.Server.WebControls.MyLinksRibbon.EnsureMySiteUrls() at Microsoft.Office.Server.WebControls.MyLinksRibbon.get_PortalMySiteUrlAvailable() at Microsoft.Office.Server.WebControls.MyLinksRibbon.OnLoad(EventArgs e) at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) Custom event details: Event Xml: <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event"> <System> <Provider Name="ASP.NET 2.0.50727.0" /> <EventID Qualifiers="32768">1309</EventID> <Level>3</Level> <Task>3</Task> <Keywords>0x80000000000000</Keywords> <TimeCreated SystemTime="2011-01-26T17:12:48.000000000Z" /> <EventRecordID>35834</EventRecordID> <Channel>Application</Channel> <Computer>PINTSPSFE02.samcstl.org</Computer> <Security /> </System> <EventData> <Data>3005</Data> <Data>An unhandled exception has occurred.</Data> <Data>1/26/2011 11:12:48 AM</Data> <Data>1/26/2011 5:12:48 PM</Data> <Data>c52fb336b7f147a3913fff3617a99d57</Data> <Data>4965</Data> <Data>2178</Data> <Data>0</Data> <Data>/LM/W3SVC/1449762715/ROOT-2-129405348166941887</Data> <Data>WSS_Minimal</Data> <Data>/</Data> <Data>C:\inetpub\wwwroot\wss\VirtualDirectories\80\</Data> <Data>PINTSPSFE02</Data> <Data> </Data> <Data>5928</Data> <Data>w3wp.exe</Data> <Data>SAMC\MossAppPool</Data> <Data>AccessViolationException</Data> <Data></Data> <Data>http://mosscluster/Pages/Home.aspx</Data> <Data>/Pages/Home.aspx</Data> <Data>10.3.60.26</Data> <Data>SAMC\BARNMD</Data> <Data>True</Data> <Data>NTLM</Data> <Data>SAMC\MossAppPool</Data> <Data>110</Data> <Data>SAMC\MossAppPool</Data> <Data>False</Data> <Data> at Microsoft.Office.Server.ObjectCache.SPCache.MossObjectCache_Tracked.Delete(String key, Boolean recursive, DeletionReason reason) at Microsoft.Office.Server.ObjectCache.SPCache.MossObjectCache_Tracked.Get(String key) at Microsoft.Office.Server.ObjectCache.SPCache.Get(String objectTypeName, String id) at Microsoft.Office.Server.Administration.UserProfileServiceProxy.GetPartitionPropertiesCache(Guid applicationID) at Microsoft.Office.Server.Administration.UserProfileApplicationProxy.get_PartitionPropertiesCache() at Microsoft.Office.Server.Administration.UserProfileApplicationProxy.DataCache.get_PartitionProperties() at Microsoft.Office.Server.Administration.UserProfileApplicationProxy.GetMySitePortalUrl(SPUrlZone zone, Guid partitionID) at Microsoft.Office.Server.Administration.UserProfileApplicationProxy.GetMySitePortalUrl(SPUrlZone zone, SPServiceContext serviceContext) at Microsoft.Office.Server.WebControls.MyLinksRibbon.EnsureMySiteUrls() at Microsoft.Office.Server.WebControls.MyLinksRibbon.get_PortalMySiteUrlAvailable() at Microsoft.Office.Server.WebControls.MyLinksRibbon.OnLoad(EventArgs e) at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) </Data> </EventData> </Event>

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• Parallelism in .NET – Part 4, Imperative Data Parallelism: Aggregation

  - by Reed

  In the article on simple data parallelism, I described how to perform an operation on an entire collection of elements in parallel.  Often, this is not adequate, as the parallel operation is going to be performing some form of aggregation. Simple examples of this might include taking the sum of the results of processing a function on each element in the collection, or finding the minimum of the collection given some criteria.  This can be done using the techniques described in simple data parallelism, however, special care needs to be taken into account to synchronize the shared data appropriately.  The Task Parallel Library has tools to assist in this synchronization. The main issue with aggregation when parallelizing a routine is that you need to handle synchronization of data.  Since multiple threads will need to write to a shared portion of data.  Suppose, for example, that we wanted to parallelize a simple loop that looked for the minimum value within a dataset: double min = double.MaxValue; foreach(var item in collection) { double value = item.PerformComputation(); min = System.Math.Min(min, value); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } This seems like a good candidate for parallelization, but there is a problem here.  If we just wrap this into a call to Parallel.ForEach, we’ll introduce a critical race condition, and get the wrong answer.  Let’s look at what happens here: // Buggy code! Do not use! double min = double.MaxValue; Parallel.ForEach(collection, item => { double value = item.PerformComputation(); min = System.Math.Min(min, value); }); This code has a fatal flaw: min will be checked, then set, by multiple threads simultaneously.  Two threads may perform the check at the same time, and set the wrong value for min.  Say we get a value of 1 in thread 1, and a value of 2 in thread 2, and these two elements are the first two to run.  If both hit the min check line at the same time, both will determine that min should change, to 1 and 2 respectively.  If element 1 happens to set the variable first, then element 2 sets the min variable, we’ll detect a min value of 2 instead of 1.  This can lead to wrong answers. Unfortunately, fixing this, with the Parallel.ForEach call we’re using, would require adding locking.  We would need to rewrite this like: // Safe, but slow double min = double.MaxValue; // Make a "lock" object object syncObject = new object(); Parallel.ForEach(collection, item => { double value = item.PerformComputation(); lock(syncObject) min = System.Math.Min(min, value); }); This will potentially add a huge amount of overhead to our calculation.  Since we can potentially block while waiting on the lock for every single iteration, we will most likely slow this down to where it is actually quite a bit slower than our serial implementation.  The problem is the lock statement – any time you use lock(object), you’re almost assuring reduced performance in a parallel situation.  This leads to two observations I’ll make: When parallelizing a routine, try to avoid locks. That being said: Always add any and all required synchronization to avoid race conditions. These two observations tend to be opposing forces – we often need to synchronize our algorithms, but we also want to avoid the synchronization when possible.  Looking at our routine, there is no way to directly avoid this lock, since each element is potentially being run on a separate thread, and this lock is necessary in order for our routine to function correctly every time. However, this isn’t the only way to design this routine to implement this algorithm.  Realize that, although our collection may have thousands or even millions of elements, we have a limited number of Processing Elements (PE).  Processing Element is the standard term for a hardware element which can process and execute instructions.  This typically is a core in your processor, but many modern systems have multiple hardware execution threads per core.  The Task Parallel Library will not execute the work for each item in the collection as a separate work item. Instead, when Parallel.ForEach executes, it will partition the collection into larger “chunks” which get processed on different threads via the ThreadPool.  This helps reduce the threading overhead, and help the overall speed.  In general, the Parallel class will only use one thread per PE in the system. Given the fact that there are typically fewer threads than work items, we can rethink our algorithm design.  We can parallelize our algorithm more effectively by approaching it differently.  Because the basic aggregation we are doing here (Min) is communitive, we do not need to perform this in a given order.  We knew this to be true already – otherwise, we wouldn’t have been able to parallelize this routine in the first place.  With this in mind, we can treat each thread’s work independently, allowing each thread to serially process many elements with no locking, then, after all the threads are complete, “merge” together the results. This can be accomplished via a different set of overloads in the Parallel class: Parallel.ForEach<TSource,TLocal>.  The idea behind these overloads is to allow each thread to begin by initializing some local state (TLocal).  The thread will then process an entire set of items in the source collection, providing that state to the delegate which processes an individual item.  Finally, at the end, a separate delegate is run which allows you to handle merging that local state into your final results. To rewriting our routine using Parallel.ForEach<TSource,TLocal>, we need to provide three delegates instead of one.  The most basic version of this function is declared as: public static ParallelLoopResult ForEach<TSource, TLocal>( IEnumerable<TSource> source, Func<TLocal> localInit, Func<TSource, ParallelLoopState, TLocal, TLocal> body, Action<TLocal> localFinally ) The first delegate (the localInit argument) is defined as Func<TLocal>.  This delegate initializes our local state.  It should return some object we can use to track the results of a single thread’s operations. The second delegate (the body argument) is where our main processing occurs, although now, instead of being an Action<T>, we actually provide a Func<TSource, ParallelLoopState, TLocal, TLocal> delegate.  This delegate will receive three arguments: our original element from the collection (TSource), a ParallelLoopState which we can use for early termination, and the instance of our local state we created (TLocal).  It should do whatever processing you wish to occur per element, then return the value of the local state after processing is completed. The third delegate (the localFinally argument) is defined as Action<TLocal>.  This delegate is passed our local state after it’s been processed by all of the elements this thread will handle.  This is where you can merge your final results together.  This may require synchronization, but now, instead of synchronizing once per element (potentially millions of times), you’ll only have to synchronize once per thread, which is an ideal situation. Now that I’ve explained how this works, lets look at the code: // Safe, and fast! double min = double.MaxValue; // Make a "lock" object object syncObject = new object(); Parallel.ForEach( collection, // First, we provide a local state initialization delegate. () => double.MaxValue, // Next, we supply the body, which takes the original item, loop state, // and local state, and returns a new local state (item, loopState, localState) => { double value = item.PerformComputation(); return System.Math.Min(localState, value); }, // Finally, we provide an Action<TLocal>, to "merge" results together localState => { // This requires locking, but it's only once per used thread lock(syncObj) min = System.Math.Min(min, localState); } ); Although this is a bit more complicated than the previous version, it is now both thread-safe, and has minimal locking.  This same approach can be used by Parallel.For, although now, it’s Parallel.For<TLocal>.  When working with Parallel.For<TLocal>, you use the same triplet of delegates, with the same purpose and results. Also, many times, you can completely avoid locking by using a method of the Interlocked class to perform the final aggregation in an atomic operation.  The MSDN example demonstrating this same technique using Parallel.For uses the Interlocked class instead of a lock, since they are doing a sum operation on a long variable, which is possible via Interlocked.Add. By taking advantage of local state, we can use the Parallel class methods to parallelize algorithms such as aggregation, which, at first, may seem like poor candidates for parallelization.  Doing so requires careful consideration, and often requires a slight redesign of the algorithm, but the performance gains can be significant if handled in a way to avoid excessive synchronization.

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• Revisiting ANTS Performance Profiler 7.4

  - by James Michael Hare

  Last year, I did a small review on the ANTS Performance Profiler 6.3, now that it’s a year later and a major version number higher, I thought I’d revisit the review and revise my last post. This post will take the same examples as the original post and update them to show what’s new in version 7.4 of the profiler. Background A performance profiler’s main job is to keep track of how much time is typically spent in each unit of code. This helps when we have a program that is not running at the performance we expect, and we want to know where the program is experiencing issues. There are many profilers out there of varying capabilities. Red Gate’s typically seem to be the very easy to “jump in” and get started with very little training required. So let’s dig into the Performance Profiler. I’ve constructed a very crude program with some obvious inefficiencies. It’s a simple program that generates random order numbers (or really could be any unique identifier), adds it to a list, sorts the list, then finds the max and min number in the list. Ignore the fact it’s very contrived and obviously inefficient, we just want to use it as an example to show off the tool: 1: // our test program 2: public static class Program 3: { 4: // the number of iterations to perform 5: private static int _iterations = 1000000; 6: 7: // The main method that controls it all 8: public static void Main() 9: { 10: var list = new List<string>(); 11: 12: for (int i = 0; i < _iterations; i++) 13: { 14: var x = GetNextId(); 15: 16: AddToList(list, x); 17: 18: var highLow = GetHighLow(list); 19: 20: if ((i % 1000) == 0) 21: { 22: Console.WriteLine("{0} - High: {1}, Low: {2}", i, highLow.Item1, highLow.Item2); 23: Console.Out.Flush(); 24: } 25: } 26: } 27: 28: // gets the next order id to process (random for us) 29: public static string GetNextId() 30: { 31: var random = new Random(); 32: var num = random.Next(1000000, 9999999); 33: return num.ToString(); 34: } 35: 36: // add it to our list - very inefficiently! 37: public static void AddToList(List<string> list, string item) 38: { 39: list.Add(item); 40: list.Sort(); 41: } 42: 43: // get high and low of order id range - very inefficiently! 44: public static Tuple<int,int> GetHighLow(List<string> list) 45: { 46: return Tuple.Create(list.Max(s => Convert.ToInt32(s)), list.Min(s => Convert.ToInt32(s))); 47: } 48: } So let’s run it through the profiler and see what happens! Visual Studio Integration First, let’s look at how the ANTS profilers integrate with Visual Studio’s menu system. Once you install the ANTS profilers, you will get an ANTS menu item with several options: Notice that you can either Profile Performance or Launch ANTS Performance Profiler. These sound similar but achieve two slightly different actions: Profile Performance: this immediately launches the profiler with all defaults selected to profile the active project in Visual Studio. Launch ANTS Performance Profiler: this launches the profiler much the same way as starting it from the Start Menu. The profiler will pre-populate the application and path information, but allow you to change the settings before beginning the profile run. So really, the main difference is that Profile Performance immediately begins profiling with the default selections, where Launch ANTS Performance Profiler allows you to change the defaults and attach to an already-running application. Let’s Fire it Up! So when you fire up ANTS either via Start Menu or Launch ANTS Performance Profiler menu in Visual Studio, you are presented with a very simple dialog to get you started: Notice you can choose from many different options for application type. You can profile executables, services, web applications, or just attach to a running process. In fact, in version 7.4 we see two new options added: ASP.NET Web Application (IIS Express) SharePoint web application (IIS) So this gives us an additional way to profile ASP.NET applications and the ability to profile SharePoint applications as well. You can also choose your level of detail in the Profiling Mode drop down. If you choose Line-Level and method-level timings detail, you will get a lot more detail on the method durations, but this will also slow down profiling somewhat. If you really need the profiler to be as unintrusive as possible, you can change it to Sample method-level timings. This is performing very light profiling, where basically the profiler collects timings of a method by examining the call-stack at given intervals. Which method you choose depends a lot on how much detail you need to find the issue and how sensitive your program issues are to timing. So for our example, let’s just go with the line and method timing detail. So, we check that all the options are correct (if you launch from VS2010, the executable and path are filled in already), and fire it up by clicking the [Start Profiling] button. Profiling the Application Once you start profiling the application, you will see a real-time graph of CPU usage that will indicate how much your application is using the CPU(s) on your system. During this time, you can select segments of the graph and bookmark them, giving them mnemonic names. This can be useful if you want to compare performance in one part of the run to another part of the run. Notice that once you select a block, it will give you the call tree breakdown for that selection only, and the relative performance of those calls. Once you feel you have collected enough information, you can click [Stop Profiling] to stop the application run and information collection and begin a more thorough analysis. Analyzing Method Timings So now that we’ve halted the run, we can look around the GUI and see what we can see. By default, the times are shown in terms of percentage of time of the total run of the application, though you can change it in the View menu item to milliseconds, ticks, or seconds as well. This won’t affect the percentages of methods, it only affects what units the times are shown. Notice also that the major hotspot seems to be in a method without source, ANTS Profiler will filter these out by default, but you can right-click on the line and remove the filter to see more detail. This proves especially handy when a bottleneck is due to a method in the BCL. So now that we’ve removed the filter, we see a bit more detail: In addition, ANTS Performance Profiler gives you the ability to decompile the methods without source so that you can dive even deeper, though typically this isn’t necessary for our purposes. When looking at timings, there are generally two types of timings for each method call: Time: This is the time spent ONLY in this method, not including calls this method makes to other methods. Time With Children: This is the total of time spent in both this method AND including calls this method makes to other methods. In other words, the Time tells you how much work is being done exclusively in this method, and the Time With Children tells you how much work is being done inclusively in this method and everything it calls. You can also choose to display the methods in a tree or in a grid. The tree view is the default and it shows the method calls arranged in terms of the tree representing all method calls and the parent method that called them, etc. This is useful for when you find a hot-spot method, you can see who is calling it to determine if the problem is the method itself, or if it is being called too many times. The grid method represents each method only once with its totals and is useful for quickly seeing what method is the trouble spot. In addition, you can choose to display Methods with source which are generally the methods you wrote (as opposed to native or BCL code), or Any Method which shows not only your methods, but also native calls, JIT overhead, synchronization waits, etc. So these are just two ways of viewing the same data, and you’re free to choose the organization that best suits what information you are after. Analyzing Method Source If we look at the timings above, we see that our AddToList() method (and in particular, it’s call to the List<T>.Sort() method in the BCL) is the hot-spot in this analysis. If ANTS sees a method that is consuming the most time, it will flag it as a hot-spot to help call out potential areas of concern. This doesn’t mean the other statistics aren’t meaningful, but that the hot-spot is most likely going to be your biggest bang-for-the-buck to concentrate on. So let’s select the AddToList() method, and see what it shows in the source window below: Notice the source breakout in the bottom pane when you select a method (from either tree or grid view). This shows you the timings in this method per line of code. This gives you a major indicator of where the trouble-spot in this method is. So in this case, we see that performing a Sort() on the List<T> after every Add() is killing our performance! Of course, this was a very contrived, duh moment, but you’d be surprised how many performance issues become duh moments. Note that this one line is taking up 86% of the execution time of this application! If we eliminate this bottleneck, we should see drastic improvement in the performance. So to fix this, if we still wanted to maintain the List<T> we’d have many options, including: delay Sort() until after all Add() methods, using a SortedSet, SortedList, or SortedDictionary depending on which is most appropriate, or forgoing the sorting all together and using a Dictionary. Rinse, Repeat! So let’s just change all instances of List<string> to SortedSet<string> and run this again through the profiler: Now we see the AddToList() method is no longer our hot-spot, but now the Max() and Min() calls are! This is good because we’ve eliminated one hot-spot and now we can try to correct this one as well. As before, we can then optimize this part of the code (possibly by taking advantage of the fact the list is now sorted and returning the first and last elements). We can then rinse and repeat this process until we have eliminated as many bottlenecks as possible. Calls by Web Request Another feature that was added recently is the ability to view .NET methods grouped by the HTTP requests that caused them to run. This can be helpful in determining which pages, web services, etc. are causing hot spots in your web applications. Summary If you like the other ANTS tools, you’ll like the ANTS Performance Profiler as well. It is extremely easy to use with very little product knowledge required to get up and running. There are profilers built into the higher product lines of Visual Studio, of course, which are also powerful and easy to use. But for quickly jumping in and finding hot spots rapidly, Red Gate’s Performance Profiler 7.4 is an excellent choice. 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• CloudBerry Online Backup 1.5 for Windows Home Server

  - by The Geek

  Overview CloudBerry Online Backup version 1.5 is a front end application for Amazon S3 storage for backing up your Windows Home Server data. It makes backing up your essential data to Amazon S3 an easy process in the event the disaster strikes. Installation You install the Cloudberry Addin as you do for any addins for Windows Home Server. On a PC on your network, browse to the shared folders on your server and open the Add-Ins folder and copy over WHS_CloudBerryOnlineBackupSetup_v1.5.0.81S3o.msi (link below), then close out of the folder. Next launch the Windows Home Server Console, click Settings, then Add-Ins. Click on the Available tab and click the Install button. It installs very quickly, and when you get the Installation Succeeded dialog click OK. You will lose connection through the Console, just click OK, then reconnect. After reconnecting, you’ll see CloudBerry Backup has been installed, and you can begin using it. You can setup a backup plan right away or find out what’s new with version 1.5. Amazon S3 Account If you don’t already have an Amazon S3 account, you’ll be prompted to create a new one. Click on the Create an account hyperlink, which takes you to the Amazon S3 page where you can sign up. After reviewing the functionality of Amazon S3, click on the Sign Up for Amazon S3 button. Enter in your contact information and accept the Amazon Web Services Customer Agreement. You’re then shown their pricing for storage plans. The amount of storage space you use will depend on your needs. It’s relatively cheap for smaller amounts of data. Just keep in mind the more data you store and download, the more S3 is going to cost. Note: Amazon S3 is introducing Reduced Redundancy Storage which will lower the cost of the data stored on S3. CloudBerry 1.5 will support this new feature. You can find out more about this new pricing structure. Note: Keep in mind that after you first sign up for an Amazon S3 account, it can take up to 24 hours to be authorized. In fact, you may want to sign up for the S3 account before installing the Add-In. After you sign up for your S3 Account, you’ll be given access credentials which you can enter in and create a Storage Bucket name. Features & Use CloudBerry is wizard driven, straight-forward and easy to use. Here we take a look at creating a backup plan. To begin, click on the Setup Backup Plan button to kick off the wizard. Select your backup mode based on the amount of features you want. In our example we’re going to select Advanced Mode as it offers more features than Simple Mode. Select your backup storage account or create a new one. You can select a default account by checking Use currently selected account as default. Now you can go through and select the files and folders you want to backup from your home server. Check the box Show physical drives to get more of a selection of files and folders. This also allows you to backup files from your data drive as well. It has full support for drive extenders so you can backup your shares as well. The cool thing about Cloudberry is it allows you to drill down specific files and folders unlike other WHS backup utilities. Next you can use advanced filters to specify files and/or folders to skip if you want. There are compression and encryption options as well. This will save storage space, bandwidth, and keep your data secure. Purge Options allow you to customize options for getting rid of older files. You can also select the option to delete files from the S3 service that have been deleted locally. Be careful with this option however, as you won’t be able to restore files if you delete them locally. You have some nice scheduling options from running backups manually, specific date and time, or recurring daily, weekly or monthly. Receive email notifications in all cases or when a backup fails. This is a good option so you know if things were successful or something failed, and you need to back it up manually. Email notifications… Give your plan a name… Then if the summary page looks good you can continue, or still go back at this point if something doesn’t look correct and needs adjusting. That’s it! You’re ready to go, and you have an option to start your first backup right away. After you’ve created a backup plan, you can go in and edit, delete, view history, or restore files. Restoring Files using CloudBerry To restore data from your backups kick off the Restore Wizard and select the backup to restore from. You can select the last backup, a specific point in time, or manually browse through the files. Browse through the directory and select the files you need to restore. Choose the destination to restore the files to. You can select from the original location, a specific location, to overwrite existing files, or set the location as the default for future restores. If the files are encrypted, enter in the correct passwords. If the summary looks good, click on Next to start the restore process. You’ll be shown a progress bar at the bottom of the screen while the files are restored. After the process has completed, close out of the Restore Wizard. In this example we restored a couple of music files to the desktop of Windows Home Server… But as shown above you can save them to the original location, other network locations, or WHS shared folders. This can make it a lot easier to keep track of files you’ve restored. You can also access different options for CloudBerry by clicking Settings in WHS Console then CloudBerry Backup. Here you can set up a new storage account, check for updates, app options, Diagnostics, and send feedback. Under Options there are several settings you can tweak to get the best experience for your WHS backups. CloudBerry Web Interface Another nice feature is the CloudBerry Web Interface so you can access your data from anywhere you have an Internet connection. To check it out in WHS Console, click on the Backup Web Interface link…you’ll probably want to bookmark the link in your favorite browser. Note: This feature is still in beta and at the time of this review, the Web Interface wasn’t up and running so we weren’t able to test it out. Performance The Cloudberry app works very well through the Windows Home Server Console. The amount of time it takes to backup or restore your data will depend on the speed of your Internet connection and size of the files. In our tests, backing up 1GB of data to the Amazon S3 account took around an hour, but we were running it on a DSL with limited upload speeds so your mileage will vary. Product Support In our experience, the team at CloudBerry offered great support in a timely manner when contacting them. You can fill out a help request through a form on their website and they also have a community forum. Conclusion We were very pleased with CloudBerry Online Backup for WHS. It’s wizard driven interface makes it extremely easy to use, and offers comprehensive backup choices for your Amazon S3 account. CloudBerry will only backup files that have been modified, so if files haven’t been changed, they won’t be backed up again.They offer a free 15 day trial and is $29.99 after that for a full license. Once you buy the app you own it, and charges to your S3 account will vary depending on the amount of data you upload. If you’re looking for an effective and easy to use front end application to backup your Windows Home Server data to your Amazon S3 account, CloudBerry is a recommended affordable choice. Download CloudBerry for Windows Home Server Sign Up For Amazon S3 Account Rating Installation: 9 Ease of Use: 8 Features: 8 Performance: 8 Product Support: 8 Similar Articles Productive Geek Tips Restore Files from Backups on Windows Home ServerGMedia Blog: Setting Up a Windows Home ServerBackup Windows Home Server Folders to an External Hard DriveBackup Your Windows Home Server Off-Site with Asus WebstorageRemove a Network Computer from Windows Home Server TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips CloudBerry Online Backup 1.5 for Windows Home Server Snagit 10 VMware Workstation 7 Acronis Online Backup Sculptris 1.0, 3D Drawing app AceStock, a Tiny Desktop Quote Monitor Gmail Button Addon (Firefox) Hyperwords addon (Firefox) Backup Outlook 2010 Daily Motivator (Firefox)

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• migration from jboss4.0.5GA to jboss5.1.0 GA

  - by rahul c

  Hi, Currently we have migrated from jboss4.0.5GA to jboss5.1.0 GA.Our application runs under jboss4.0.5GA well.The reason for migration to enable web service. I cann't find a way to create a web service on jboss 4.0.5 GA. while running on jboss 5.1.0 GA with jbossws-cxf-3.2.1.GA installed on it. i got following error 18:53:43,699 INFO [STDOUT] 2009-11-30 18:53:43,699 INFO org.springframework.core.CollectionFactory - JDK 1.4+ collections available 18:53:43,700 INFO [STDOUT] 2009-11-30 18:53:43,700 INFO org.springframework.core.CollectionFactory - Commons Collections 3.x available 18:53:43,973 INFO [STDOUT] 2009-11-30 18:53:43,972 INFO org.springframework.beans.factory.xml.XmlBeanDefinitionReader - Loading XML bean definitions from ServletContext resource [/WEB-INF/applicationContext.xml] 18:53:44,308 INFO [STDOUT] 2009-11-30 18:53:44,302 ERROR org.springframework.web.context.ContextLoader - Context initialization failed org.springframework.beans.factory.BeanDefinitionStoreException: Unexpected exception parsing XML document from ServletContext resource [/WEB-INF/applicationContext.xml]; nested exception is java.lang.IllegalArgumentException: Class [org.apache.cxf.transport.http_jetty.spring.NamespaceHandler] does not implement the NamespaceHandler interface Caused by: java.lang.IllegalArgumentException: Class [org.apache.cxf.transport.http_jetty.spring.NamespaceHandler] does not implement the NamespaceHandler interface at org.springframework.beans.factory.xml.DefaultNamespaceHandlerResolver.initHandlerMappings(DefaultNamespaceHandlerResolver.java:119) at org.springframework.beans.factory.xml.DefaultNamespaceHandlerResolver.(DefaultNamespaceHandlerResolver.java:96) at org.springframework.beans.factory.xml.DefaultNamespaceHandlerResolver.(DefaultNamespaceHandlerResolver.java:82) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.createDefaultNamespaceHandlerResolver(XmlBeanDefinitionReader.java:526) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.createReaderContext(XmlBeanDefinitionReader.java:515) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.registerBeanDefinitions(XmlBeanDefinitionReader.java:495) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:390) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:340) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:317) at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:125) at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:141) at org.springframework.web.context.support.XmlWebApplicationContext.loadBeanDefinitions(XmlWebApplicationContext.java:123) at org.springframework.web.context.support.XmlWebApplicationContext.loadBeanDefinitions(XmlWebApplicationContext.java:91) at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:94) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:292) at org.springframework.web.context.support.AbstractRefreshableWebApplicationContext.refresh(AbstractRefreshableWebApplicationContext.java:156) at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:246) at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:184) at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:49) at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:3910) at org.apache.catalina.core.StandardContext.start(StandardContext.java:4393) at org.jboss.web.tomcat.service.deployers.TomcatDeployment.performDeployInternal(TomcatDeployment.java:310) at org.jboss.web.tomcat.service.deployers.TomcatDeployment.performDeploy(TomcatDeployment.java:142) at org.jboss.web.deployers.AbstractWarDeployment.start(AbstractWarDeployment.java:461) at org.jboss.web.deployers.WebModule.startModule(WebModule.java:118) at org.jboss.web.deployers.WebModule.start(WebModule.java:97) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:157) at org.jboss.mx.server.Invocation.dispatch(Invocation.java:96) at org.jboss.mx.server.Invocation.invoke(Invocation.java:88) at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:264) at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:668) at org.jboss.system.microcontainer.ServiceProxy.invoke(ServiceProxy.java:206) at $Proxy38.start(Unknown Source) at org.jboss.system.microcontainer.StartStopLifecycleAction.installAction(StartStopLifecycleAction.java:42) at org.jboss.system.microcontainer.StartStopLifecycleAction.installAction(StartStopLifecycleAction.java:37) at org.jboss.dependency.plugins.action.SimpleControllerContextAction.simpleInstallAction(SimpleControllerContextAction.java:62) at org.jboss.dependency.plugins.action.AccessControllerContextAction.install(AccessControllerContextAction.java:71) at org.jboss.dependency.plugins.AbstractControllerContextActions.install(AbstractControllerContextActions.java:51) at org.jboss.dependency.plugins.AbstractControllerContext.install(AbstractControllerContext.java:348) at org.jboss.system.microcontainer.ServiceControllerContext.install(ServiceControllerContext.java:286) at org.jboss.dependency.plugins.AbstractController.install(AbstractController.java:1631) at org.jboss.dependency.plugins.AbstractController.incrementState(AbstractController.java:934) at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:1082) at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:984) at org.jboss.dependency.plugins.AbstractController.change(AbstractController.java:822) at org.jboss.dependency.plugins.AbstractController.change(AbstractController.java:553) at org.jboss.system.ServiceController.doChange(ServiceController.java:688) at org.jboss.system.ServiceController.start(ServiceController.java:460) at org.jboss.system.deployers.ServiceDeployer.start(ServiceDeployer.java:163) at org.jboss.system.deployers.ServiceDeployer.deploy(ServiceDeployer.java:99) at org.jboss.system.deployers.ServiceDeployer.deploy(ServiceDeployer.java:46) at org.jboss.deployers.spi.deployer.helpers.AbstractSimpleRealDeployer.internalDeploy(AbstractSimpleRealDeployer.java:62) at org.jboss.deployers.spi.deployer.helpers.AbstractRealDeployer.deploy(AbstractRealDeployer.java:50) at org.jboss.deployers.plugins.deployers.DeployerWrapper.deploy(DeployerWrapper.java:171) at org.jboss.deployers.plugins.deployers.DeployersImpl.doDeploy(DeployersImpl.java:1439) at org.jboss.deployers.plugins.deployers.DeployersImpl.doInstallParentFirst(DeployersImpl.java:1157) at org.jboss.deployers.plugins.deployers.DeployersImpl.doInstallParentFirst(DeployersImpl.java:1178) at org.jboss.deployers.plugins.deployers.DeployersImpl.install(DeployersImpl.java:1098) at org.jboss.dependency.plugins.AbstractControllerContext.install(AbstractControllerContext.java:348) at org.jboss.dependency.plugins.AbstractController.install(AbstractController.java:1631) at org.jboss.dependency.plugins.AbstractController.incrementState(AbstractController.java:934) at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:1082) at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:984) at org.jboss.dependency.plugins.AbstractController.change(AbstractController.java:822) at org.jboss.dependency.plugins.AbstractController.change(AbstractController.java:553) at org.jboss.deployers.plugins.deployers.DeployersImpl.process(DeployersImpl.java:781) at org.jboss.deployers.plugins.main.MainDeployerImpl.process(MainDeployerImpl.java:702) at org.jboss.system.server.profileservice.repository.MainDeployerAdapter.process(MainDeployerAdapter.java:117) at org.jboss.system.server.profileservice.repository.ProfileDeployAction.install(ProfileDeployAction.java:70) at org.jboss.system.server.profileservice.repository.AbstractProfileAction.install(AbstractProfileAction.java:53) at org.jboss.system.server.profileservice.repository.AbstractProfileService.install(AbstractProfileService.java:361) at org.jboss.dependency.plugins.AbstractControllerContext. 18:53:44,313 INFO [STDOUT] install(AbstractControllerContext.java:348) at org.jboss.dependency.plugins.AbstractController.install(AbstractController.java:1631) at org.jboss.dependency.plugins.AbstractController.incrementState(AbstractController.java:934) at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:1082) at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:984) at org.jboss.dependency.plugins.AbstractController.change(AbstractController.java:822) at org.jboss.dependency.plugins.AbstractController.change(AbstractController.java:553) at org.jboss.system.server.profileservice.repository.AbstractProfileService.activateProfile(AbstractProfileService.java:306) at org.jboss.system.server.profileservice.ProfileServiceBootstrap.start(ProfileServiceBootstrap.java:271) at org.jboss.bootstrap.AbstractServerImpl.start(AbstractServerImpl.java:461) at org.jboss.Main.boot(Main.java:221) at org.jboss.Main$1.run(Main.java:556) at java.lang.Thread.run(Thread.java:619) 18:53:44,315 ERROR [[/smartLMS]] Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener org.springframework.beans.factory.BeanDefinitionStoreException: Unexpected exception parsing XML document from ServletContext resource [/WEB-INF/applicationContext.xml]; nested exception is java.lang.IllegalArgumentException: Class [org.apache.cxf.transport.http_jetty.spring.NamespaceHandler] does not implement the NamespaceHandler interface Caused by: java.lang.IllegalArgumentException: Class [org.apache.cxf.transport.http_jetty.spring.NamespaceHandler] does not implement the NamespaceHandler interface at org.springframework.beans.factory.xml.DefaultNamespaceHandlerResolver.initHandlerMappings(DefaultNamespaceHandlerResolver.java:119) at org.springframework.beans.factory.xml.DefaultNamespaceHandlerResolver.(DefaultNamespaceHandlerResolver.java:96) at org.springframework.beans.factory.xml.DefaultNamespaceHandlerResolver.(DefaultNamespaceHandlerResolver.java:82) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.createDefaultNamespaceHandlerResolver(XmlBeanDefinitionReader.java:526) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.createReaderContext(XmlBeanDefinitionReader.java:515) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.registerBeanDefinitions(XmlBeanDefinitionReader.java:495) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:390) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:340) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:317) at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:125) at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:141) at org.springframework.web.context.support.XmlWebApplicationContext.loadBeanDefinitions(XmlWebApplicationContext.java:123) Thanks, Rahul.

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• CodePlex Daily Summary for Wednesday, March 10, 2010

  CodePlex Daily Summary for Wednesday, March 10, 2010New ProjectsASP.NET jQuery MessageBox: The ASP.NET jQuery it's an Web User Control that uses jQuery framework to enable diferent ways to present information to the user, by using these ...CommentRemover: Utility for removing comments from source codes. Support PL/SQL, Delphi, C/C#/C++ Developed in C# Requirement Microsoft .NET Framework 3.5DotNetNuke® RadMenu: DNNRadMenu makes it easy to create skins which use telerik RadMenu functionality. Licensing permits anyone (including designers) to use the compon...DotNetNuke® Skin AlphaBrisk: A DotNetNuke Design Challenge skin package submitted to the "Web Standards" category by dnnskin.net. Eight themes using transparent png, div, CSS, ...DotNetNuke® Skin Collaborate: A DotNetNuke Design Challenge skin package submitted to the "Modern Business" category by Cuong Dang of R2Integrated. This package is 100% XHTML an...DotNetNuke® Skin TR: A DotNetNuke Design Challenge skin package submitted to the "Out of the box" category by Tracy Wittenkeller of T-Worx. This package is 100% XHTML, ...Encrypted Notes: Encrypted Notes is similar to Notes, but uses Triple DES to encrypt text and files. It has a random key generator, and can save the key. It is deve...FalconLobby: FalconLobby is an authorized AddOn for Falcon 4.0 Allied Force which was created to support the multiplayer experience. FalconLobby retrieves the l...INETA Europe WebSite: Website for INETA EuropeInsert a Favorite (Bookmark) plugin for Windows Live Writer: This Windows Live Writer plugin allows you to select a Favorite (Bookmark) and insert it into your blog entry.Javascript Lib: an javascript libraryjqGrid ASP.Net MVC Control: A fully integrated ASP.Net MVC (2.0) grid control based on the successfull jqGrid plugin for the jQuery jscript framework. Among the features of...Mosaictor: Mosaictor is a per project of mine that I started halfway my education. It is a photo mosaic creator using locally saved files and files obtained t...Notes: Notes is a simple but fast text editor. It can save in many text formats, and includes many features, such as templates (soon to be customizable), ...notmuchweb: A web frontend for notmuchPervasiveID: The PID is actively involved in Open Source ID community-building and education. PID members frequently travel the world to attend ID conferences a...Proyect Electronica: Proyecto de electronicaRapidshare Downloader 2: Rapidshare Downloader 2ROAD is Rapid Oberon Application Development: A suite of integrated tools for the develpment of Oberon-2 applicationSDNTFSIntegration: TFS Integration.SilverlightImageUpload: SilverlightImageUploadSMIL - SharePoint Map Integration Layer: .Useful SharePoint Site Workflow Utilities: This project aims to make it easy use SharePoint 2010's Site Workflows as "event handlers" for various back end systems by providing ways to start ...Windows Media Autorization: Windows Media Autorizaton PlugIn for windows media 9 WinMo Twitter Widget StarterKit: This project will allow you to quickly create Widgets that run on a Windows Mobile 6.5 phone to allow you to view Tweets designated by a hash tag. ...XNA 3D World Studio Content Pipeline: XNA 3D World Studio Content Pipeline New ReleasesAPSales - CRM Software as a Service: APSales 0.1.2: This version add some interesting features to the project: Implements a Grid Control Custom View Query Use lastest version(2.0.2) of APEnnead.net ...ASP.NET jQuery MessageBox: ASP.NET jQuery MessageBox 0.1: Project Description The ASP.NET jQuery it's an Web User Control que uses jQuery framework to enable diferent ways to present information to the use...BTP Tools: CSBC+CUVC+HCSBC.dict files 2010-03-09: a space character should be only between <Strong Number Pattern> and <Count> like: <Text><Strong Number pattern><space character> <Count> The abov...Citrix HDX MediaStream for Flash System Verifier: HDX Flash Verifier Beta (v1.20): Reduced the number of exceptions that terminate the verification process.Code examples, utilities and misc from Lars Wilhelmsen [MVP]: LarsW.MexEdmxFixer 1.5: Added some missing sub elements from the EDMX file's Designer element; Connection and Output. Without them, some of the properties in the designer ...CommonLibrary.NET: CommonLibrary.NET 0.9.4 - Beta 2: A collection of very reusable code and components in C# 3.5 ranging from ActiveRecord, Csv, Command Line Parsing, Configuration, Holiday Calendars,...Encrypted Notes: Source Code: This has the all the code for Encrypted Notes in a Text file.Hybrid Windows Service: Release Assembly: Main Assembly. Usage: 1. Add reference to this dll in your 'Windows Service' project. 2. Replace references to ServiceBase to HybridServiceBase in...jqGrid ASP.Net MVC Control: Version 1.0.0.0: Initial Versionkdar: KDAR 0.0.16: KDAR - Kernel Debugger Anti Rootkit - KINTERRUPT object check added - load image notifier check addedlatex2mathml: 1.0 alpha: This is the first public release of Latex2MathML. Lots are left to add and fix. I encourage you to test it. If something goes wrong, send me the lo...MapWindow GIS: MapWindow 6.0 msi (March 9): This fixes a bug with saving and opening maps.Microsoft Research Biology Extension for Excel: MSR Biology Extension for Excel - Beta 2 (Update): This is an updated release for the Beta 2 Installer for the MSR Biology Extension for Excel. A couple of identified issues with the installation f...Notes: Notes 5.2: This is the latest version of Notes (5.2). It has an installer - it will create a directory 'CPascoe' in My Documents. Once you have extracted the...Notes: Source Code: This has the all the code for Notes in a Text file.RedBulb for XNA Framework: Tree Massacre XMAS Edition (Sample): Tree Massacre XMAS Edition Source Code and Creators Club Package http://bayimg.com/image/jalkiaacb.jpgRoTwee: RoTwee (7.0.2.0): Now color mode is introduced to RoTwee. Push change color button and you can change color mode of RoTwee. Recommended mode is active rainbow mode :)SharePoint Team-Mailer: SharePoint Team-Mailer v1.0: Recommended versionsPWadmin: pwAdmin v0.7_nightly: Nightly Build --------------------- + Target JRE -> 1.5.0_21 + Target ApplicationServer -> Apache Tomcat 5.5.28 + Added xml editor (only working fo...SQL Server PowerShell Extensions: 2.1 Production: Release 2.1 re-implements SQLPSX as PowersShell version 2.0 modules. SQLPSX consists of 9 modules with 133 advanced functions, 2 cmdlets and 7 scri...TMap for VS2010: TMap for VS2010 (MSF Agile) RC Release: Release of the TMap process template for VS2010 combined with the MSF Agile process template basd on the Release Candidate. The references to the g...TS3QueryLib.Net: TS3QueryLib.Net Version 0.19.14.0: Changelog Added property "IsClientRecording" to class "ClientListEntry" which is used in method "GetClientList" of QueryRunner class. (Change of Be...VCC: Latest build, v2.1.30309.0: Automatic drop of latest buildWinMo Twitter Widget StarterKit: Tweet Viewer Files: Files necessary to create your own Tweet ViewerWPF AutoComplete TextBox Control: Version 1.1: This release includes accumulated bug fixes since the initial release. Besides, adds experimental asynchronous support. Sample application gets...XNA 3D World Studio Content Pipeline: XNA 3DWS Content Pipeline: This is an rar file containing the latest content importer codeMost Popular ProjectsMetaSharpWBFS ManagerRawrAJAX Control ToolkitMicrosoft SQL Server Product Samples: DatabaseSilverlight ToolkitWindows Presentation Foundation (WPF)ASP.NETMicrosoft SQL Server Community & SamplesASP.NET Ajax LibraryMost Active ProjectsUmbraco CMSRawrSDS: Scientific DataSet library and toolsjQuery Library for SharePoint Web ServicesBlogEngine.NETN2 CMSFasterflect - A Fast and Simple Reflection APIFarseer Physics Enginepatterns & practices – Enterprise LibraryCaliburn: An Application Framework for WPF and Silverlight

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• Server overloaded with log messages: tty_release_dev: pts0: read/write wait queue active!

  - by Raph

  In the logs, I have this (extract from the full kernel messages logges at 06:01:14): Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.863038] BUG: unable to handle kernel NULL pointer dereference at 0000000000000015 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861081] Process telnet (pid: 20247, threadinfo ffff8800f8598000, task ffff8800024d4500) And then the server logs flooded by this message: Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861547] tty_release_dev: pts0: read/write wait queue active! In the end, 2 hours later, I had to reboot because it had become inaccessible: the load hat grown to 160%. The last command does not show anyone logged on pts0 at that time. I also don't know where this telnet process could come from.... This is an AWS instance running UBUNTU 10.04 LTS And here are the complete logs: Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.863038] BUG: unable to handle kernel NULL pointer dereference at 0000000000000015 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861007] IP: [<ffffffff81363dde>] n_tty_read+0x2ce/0x970 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861019] PGD ee13d067 PUD f8698067 PMD 0 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861025] Oops: 0000 [#1] SMP Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861028] last sysfs file: /sys/devices/xen/vbd-2208/block/sdk/removable Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861032] CPU 0 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861034] Modules linked in: ipv6 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861040] Pid: 20247, comm: telnet Not tainted 2.6.32-312-ec2 #24-Ubuntu Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861042] RIP: e030:[<ffffffff81363dde>] [<ffffffff81363dde>] n_tty_read+0x2ce/0x970 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861047] RSP: e02b:ffff8800f8599d88 EFLAGS: 00010246 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861049] RAX: 0000000000000015 RBX: ffff8800f8598000 RCX: 0000000001aed069 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861052] RDX: 0000000000000000 RSI: ffff8800f8599e67 RDI: ffff8801dd833d1c Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861054] RBP: ffff8800f8599e98 R08: ffffffff8135eb10 R09: 7fffffffffffffff Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861057] R10: 0000000000000000 R11: 0000000000000246 R12: ffff8801dd833800 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861059] R13: 0000000000000000 R14: ffff8801dd833a68 R15: ffff8801dd833d1c Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861065] FS: 00007f90121f6720(0000) GS:ffff880002c40000(0000) knlGS:0000000000000000 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861068] CS: e033 DS: 0000 ES: 0000 CR0: 000000008005003b Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861070] CR2: 0000000000000015 CR3: 0000000032a59000 CR4: 0000000000002660 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861073] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861076] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861081] Process telnet (pid: 20247, threadinfo ffff8800f8598000, task ffff8800024d4500) Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861083] Stack: Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861085] 0000000000000000 0000000001aed069 ffff8801dd8339c8 ffff8800024d4500 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861089] <0> ffff8801dd8339c0 ffff8801dd833c90 0000000001aed027 ffff8800024d4500 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861094] <0> ffff8801dd8338d8 0000000000000000 ffff8800024d4500 0000000000000000 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861099] Call Trace: Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861107] [<ffffffff81034bc0>] ? default_wake_function+0x0/0x10 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861113] [<ffffffff8135ebb6>] tty_read+0xa6/0xf0 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861118] [<ffffffff810ee7e5>] vfs_read+0xb5/0x1a0 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861122] [<ffffffff810ee91c>] sys_read+0x4c/0x80 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861127] [<ffffffff81009ba8>] system_call_fastpath+0x16/0x1b Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861131] [<ffffffff81009b40>] ? system_call+0x0/0x52 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861133] Code: 85 d2 0f 84 92 00 00 00 45 8b ac 24 5c 02 00 00 f0 45 0f b3 2e 45 19 ed 49 63 84 24 5c 02 00 00 49 8b 94 24 50 02 00 00 4c 89 ff <0f> be 1c 02 e8 a9 d3 14 00 41 8b 94 24 5c 02 00 00 41 83 ac 24 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861171] RIP [<ffffffff81363dde>] n_tty_read+0x2ce/0x970 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861175] RSP <ffff8800f8599d88> Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861171] RIP [<ffffffff81363dde>] n_tty_read+0x2ce/0x970 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861175] RSP <ffff8800f8599d88> Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861177] CR2: 0000000000000015 Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861205] ---[ end trace f10eee2057ff4f6b ]--- Apr 21 06:01:14 ip-10-49-109-107 kernel: [233185.861547] tty_release_dev: pts0: read/write wait queue active!

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• NINE Questions with Michelle Juett

  - by NINEQuestions

  Michelle Juett is one of the more interesting people I know, even though we’ve never met face to face. She’s part artist, part techie and all cool. We “met” via my good buddy George Clingerman and have plotting to take over the world, errr… I mean “collaborating” ever since. If you happen to live in the Seattle area, you can catch her and her work at Sakura Con on April 2-4, 2010 and various other gamer and art cons throughout the year. You can also find her on Twitter as @Shelldragon. Now that you know a little bit, I’ll let her tell you the rest of the story in these NINE Questions: 1. Where are you from? I was born in Clearwater, Florida. I like to tell people I'm from the Bermuda Triangle, it just makes explaining myself so much easier. My family moved to Washington when I was 5 and I've been in the Pacific Northwest ever since. We like to QQ about the rain but we really love the green trees and clean water. 2. What do you do? I fight evil by moonlight and win love by daylight.. or something like that.  I’ve been in quality assurance for games during the day since January 2008 and an artist for life. I currently work in QA for a really awesome game company in Bellevue.  At home, I work on personal digital art, making game assets as well as other random freelance projects as they pop up. 3. How did you get to where you are now? I'm still not where I want to be but I'm getting closer. The biggest piece of advice I can give is to work hard and never settle for the minimum required. I tend to overwork myself but I've never regretted it. You can want something really bad but if you aren't willing to work for it, then you can't expect it to just happen. I've always drawn and had an unhealthy love for video games that I was told I’d grow out of.  I knew I would not ‘grow out’ of games and that real adults make them and I could too. After I graduated, in searching for jobs, I discovered game testing. I figured this would be a good way to get my foot in the door and start networking. I’ve worked with consoles, websites and now, PC games.  I stuck with my journey, although it has been a rocky one, daylighting as a tester and moonlighting as an artist. I'm still on that journey but I wouldn't have it any other way. Test has given me a perspective that is difficult, if not impossible, to obtain any other way. It gives an unconditional respect for other hard working testers and an insight into creative problem solving. 4. So video game testing probably sounds WAY cooler than the reality. What's it like? What's a given day for you? Game testers don't get a lot of respect because of their stigmas and the fact most people don't actually know what we do.  People hear about the opening and closing disc trays all day. Many places do treat their testers like numbers. It all depends on where you work and how awesome your company is. I've had to deal with a lot of bad work situations to get to a really good one. QA exists to ensure the game is as flawless and enjoyable as it can be by the time it has to leave the nest and go out into the world. This includes everything obvious: “can I beat the level and save the princess?” to the more obscure: ‘What happens when I lose internet connection while trying to save right before falling into a pit to my death while holding the jump key then my cat pulls out my memory card and hides it in her litter box?” On the dev side, for developers, testers can be very scary people. Especially when the test team is not in house and you can’t see each other’s faces.  I've seen both sides. We don't mean to hurt your feelings. We really DO love you and want your game to be the best it can be! It can be some serious tough love. 5. You are also an accomplished artist. Got any major projects right now you'd like to talk about? LOL, I don't know if I’d say I'm an accomplished artist just yet. I’m still a long way from where I want to be. I figure that’s what makes you grow though: the desire to never stop improving. I like QA but I want to be a full time artist. I was lucky enough to register for a table at Sakura Con in the 11 second window that the tables sold out. As such, I’ll be selling my wares in the Artist Alley April 2-4th. Part of preparing for this is actually making the art to be sold there. Anime is a fun pass time but I don’t draw a whole lot of it so I’m making up for lost time. As I seem to enjoy burying myself in work, I’m an art lead for a secret project that’s so secret I might be killed tonight for even mentioning it. I also take on various freelance projects and do what I can to help out indie games. I discovered the XNA community a year and a half ago and developed a love for Indies when I was writing a weekly newsletter on XBLA news. I’m a little late to the party but I find myself in a unique position where I am an artist and also have technical skills in games. While not programmer myself, I have a lot of game sense and experience. I hope to make some awesome happen. Lastly, I have an ongoing web comic Shell’s Angels) that tends to get neglected when I get busy. I still love drawing comics and keep a little book with me to sketch down ideas as they pop into my head. I may pick it back up again as a larger project sometime in the future. 6. Can you talk about any of the other freelance projects you're doing or are you sworn to secrecy on those too? We wouldn't want a team of game developer ninjas to take you out or anything. All my projects are currently 2d. I have personal projects such as the ongoing comic as well as a graphic novel I've been picking at here and there. My main focus until April is Sakura Con, Sakura Con, Sakura Con.  I see it as a great way to get exposure and convention experience. I found out I love conventions a couple years ago and I want to get more involved in them. 7. As an artist, what is your weapon of choice? What do you use to get most of your stuff done? I am a Photoshop Hero and I have the hoodie to prove it. (http://www.pennyarcademerch.com/pah090011.html) I've dabbled in other paint programs but I always gravitate back to Photoshop. She is my one true love. I'd like to learn programs like Flash or Anime Studio when I get a bit more time because of their animation abilities. I've worked on frame by frame animation forever but I would love to learn 2d rigging. Still, nothing can compare to a simple sketchpad and a pencil. I always have one on me in case I come across or think of something interesting and can't get to a computer. If the Courier ever comes to exist it will be an ideal weapon for me. 8. You did some videos too, depicting the art creation process. What was the motivation behind those? The creative process is just as important as the final product, if not more so.  I've always loved watching speed paint videos and wanted to try it out myself. Turns out it's a lot of work and time but it's definitely fun to go back and rewatch them. Art isn't always the end result and is more often the process itself. 9. Got any interesting tattoos? Designed any for yourself or other people? Not yet, but not for lack of desire. I've toiled over what and where for years. Last year, I finally decided the back of my shoulders would be the place. Like anything permanent, I want it to have meaning. I thought of somehow incorporating games but I couldn't find something I felt would stand the test of time even with all the classic sprite games. I'm very picky so we'll see if I can get something solid decided. Come see me at Sakura Con April 2 -4!!!

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• Windows Azure AppFabric: ServiceBus Queue WPF Sample

  - by xamlnotes

  The latest version of the AppFabric ServiceBus now has support for queues and topics. Today I will show you a bit about using queues and also talk about some of the best practices in using them. If you are just getting started, you can check out this site for more info on Windows Azure. One of the 1st things I thought if when Azure was announced back when was how we handle fault tolerance. Web sites hosted in Azure are no much of an issue unless they are using SQL Azure and then you must account for potential fault or latency issues. Today I want to talk a bit about ServiceBus and how to handle fault tolerance.  And theres stuff like connecting to the servicebus and so on you have to take care of. To demonstrate some of the things you can do, let me walk through this sample WPF app that I am posting for you to download. To start off, the application is going to need things like the servicenamespace, issuer details and so forth to make everything work.  To facilitate this I created settings in the wpf app for all of these items. Then I mapped a static class to them and set the values when the program loads like so: StaticElements.ServiceNamespace = Convert.ToString(Properties.Settings.Default["ServiceNamespace"]); StaticElements.IssuerName = Convert.ToString(Properties.Settings.Default["IssuerName"]); StaticElements.IssuerKey = Convert.ToString(Properties.Settings.Default["IssuerKey"]); StaticElements.QueueName = Convert.ToString(Properties.Settings.Default["QueueName"]);   Now I can get to each of these elements plus some other common values or instances directly from the StaticElements class. Now, lets look at the application.  The application looks like this when it starts:   The blue graphic represents the queue we are going to use.  The next figure shows the form after items were added and the queue stats were updated . You can see how the queue has grown: To add an item to the queue, click the Add Order button which displays the following dialog: After you fill in the form and press OK, the order is published to the ServiceBus queue and the form closes. The application also allows you to read the queued items by clicking the Process Orders button. As you can see below, the form shows the queued items in a list and the  queue has disappeared as its now empty. In real practice we normally would use a Windows Service or some other automated process to subscribe to the queue and pull items from it. I created a class named ServiceBusQueueHelper that has the core queue features we need. There are three public methods: * GetOrCreateQueue – Gets an instance of the queue description if the queue exists. if not, it creates the queue and returns a description instance. * SendMessageToQueue = This method takes an order instance and sends it to the queue. The call to the queue is wrapped in the ExecuteAction method from the Transient Fault Tolerance Framework and handles all the retry logic for the queue send process. * GetOrderFromQueue – Grabs an order from the queue and returns a typed order from the queue. It also marks the message complete so the queue can remove it.   Now lets turn to the WPF window code (MainWindow.xaml.cs). The constructor contains the 4 lines shown about to setup the static variables and to perform other initialization tasks. The next few lines setup certain features we need for the ServiceBus: TokenProvider credentials = TokenProvider.CreateSharedSecretTokenProvider(StaticElements.IssuerName, StaticElements.IssuerKey); Uri serviceUri = ServiceBusEnvironment.CreateServiceUri("sb", StaticElements.ServiceNamespace, string.Empty); StaticElements.CurrentNamespaceManager = new NamespaceManager(serviceUri, credentials); StaticElements.CurrentMessagingFactory = MessagingFactory.Create(serviceUri, credentials); The next two lines update the queue name label and also set the timer to 20 seconds.             QueueNameLabel.Content = StaticElements.QueueName;             _timer.Interval = TimeSpan.FromSeconds(20);             Next I call the UpdateQueueStats to initialize the UI for the queue:             UpdateQueueStats();             _timer.Tick += new EventHandler(delegate(object s, EventArgs a)                         {                      UpdateQueueStats();                  });             _timer.Start();         } The UpdateQueueStats method shown below. You can see that it uses the GetOrCreateQueue method mentioned earlier to grab the queue description, then it can get the MessageCount property.         private void UpdateQueueStats()         {             _queueDescription = _serviceBusQueueHelper.GetOrCreateQueue();             QueueCountLabel.Content = "(" + _queueDescription.MessageCount + ")";             long count = _queueDescription.MessageCount;             long queueWidth = count * 20;             QueueRectangle.Width = queueWidth;             QueueTickCount += 1;             TickCountlabel.Content = QueueTickCount.ToString();         }   The ReadQueueItemsButton_Click event handler calls the GetOrderFromQueue method and adds the order to the listbox. If you look at the SendQueueMessageController, you can see the SendMessage method that sends an order to the queue. Its pretty simple as it just creates a new CustomerOrderEntity instance,fills it and then passes it to the SendMessageToQueue. As you can see, all of our interaction with the queue is done through the helper class (ServiceBusQueueHelper). Now lets dig into the helper class. First, before you create anything like this, download the Transient Fault Handling Framework. Microsoft provides this free and they also provide the C# source. Theres a great article that shows how to use this framework with ServiceBus. I included the entire ServiceBusQueueHelper class in List 1. Notice the using statements for TransientFaultHandling: using Microsoft.AzureCAT.Samples.TransientFaultHandling; using Microsoft.AzureCAT.Samples.TransientFaultHandling.ServiceBus; The SendMessageToQueue in Listing 1 shows how to use the async send features of ServiceBus with them wrapped in the Transient Fault Handling Framework.  It is not much different than plain old ServiceBus calls but it sure makes it easy to have the fault tolerance added almost for free. The GetOrderFromQueue uses the standard synchronous methods to access the queue. The best practices article walks through using the async approach for a receive operation also.  Notice that this method makes a call to Receive to get the message then makes a call to GetBody to get a new strongly typed instance of CustomerOrderEntity to return. Listing 1 using System; using System.Collections.Generic; using System.Linq; using System.Text; using Microsoft.AzureCAT.Samples.TransientFaultHandling; using Microsoft.AzureCAT.Samples.TransientFaultHandling.ServiceBus; using Microsoft.ServiceBus; using Microsoft.ServiceBus.Messaging; using System.Xml.Serialization; using System.Diagnostics; namespace WPFServicebusPublishSubscribeSample {     class ServiceBusQueueHelper     {         RetryPolicy currentPolicy = new RetryPolicy<ServiceBusTransientErrorDetectionStrategy>(RetryPolicy.DefaultClientRetryCount);         QueueClient currentQueueClient;         public QueueDescription GetOrCreateQueue()         {                        QueueDescription queue = null;             bool createNew = false;             try             {                 // First, let's see if a queue with the specified name already exists.                 queue = currentPolicy.ExecuteAction<QueueDescription>(() => { return StaticElements.CurrentNamespaceManager.GetQueue(StaticElements.QueueName); });                 createNew = (queue == null);             }             catch (MessagingEntityNotFoundException)             {                 // Looks like the queue does not exist. We should create a new one.                 createNew = true;             }             // If a queue with the specified name doesn't exist, it will be auto-created.             if (createNew)             {                 try                 {                     var newqueue = new QueueDescription(StaticElements.QueueName);                     queue = currentPolicy.ExecuteAction<QueueDescription>(() => { return StaticElements.CurrentNamespaceManager.CreateQueue(newqueue); });                 }                 catch (MessagingEntityAlreadyExistsException)                 {                     // A queue under the same name was already created by someone else,                     // perhaps by another instance. Let's just use it.                     queue = currentPolicy.ExecuteAction<QueueDescription>(() => { return StaticElements.CurrentNamespaceManager.GetQueue(StaticElements.QueueName); });                 }             }             currentQueueClient = StaticElements.CurrentMessagingFactory.CreateQueueClient(StaticElements.QueueName);             return queue;         }         public void SendMessageToQueue(CustomerOrderEntity Order)         {             BrokeredMessage msg = null;             GetOrCreateQueue();             // Use a retry policy to execute the Send action in an asynchronous and reliable fashion.             currentPolicy.ExecuteAction             (                 (cb) =>                 {                     // A new BrokeredMessage instance must be created each time we send it. Reusing the original BrokeredMessage instance may not                     // work as the state of its BodyStream cannot be guaranteed to be readable from the beginning.                     msg = new BrokeredMessage(Order);                     // Send the event asynchronously.                     currentQueueClient.BeginSend(msg, cb, null);                 },                 (ar) =>                 {                     try                     {                         // Complete the asynchronous operation.                         // This may throw an exception that will be handled internally by the retry policy.                         currentQueueClient.EndSend(ar);                     }                     finally                     {                         // Ensure that any resources allocated by a BrokeredMessage instance are released.                         if (msg != null)                         {                             msg.Dispose();                             msg = null;                         }                     }                 },                 (ex) =>                 {                     // Always dispose the BrokeredMessage instance even if the send                     // operation has completed unsuccessfully.                     if (msg != null)                     {                         msg.Dispose();                         msg = null;                     }                     // Always log exceptions.                     Trace.TraceError(ex.Message);                 }             );         }                 public CustomerOrderEntity GetOrderFromQueue()         {             CustomerOrderEntity Order = new CustomerOrderEntity();             QueueClient myQueueClient = StaticElements.CurrentMessagingFactory.CreateQueueClient(StaticElements.QueueName, ReceiveMode.PeekLock);             BrokeredMessage message;             ServiceBusQueueHelper serviceBusQueueHelper = new ServiceBusQueueHelper();             QueueDescription queueDescription;             queueDescription = serviceBusQueueHelper.GetOrCreateQueue();             if (queueDescription.MessageCount > 0)             {                 message = myQueueClient.Receive(TimeSpan.FromSeconds(90));                 if (message != null)                 {                     try                     {                         Order = message.GetBody<CustomerOrderEntity>();                         message.Complete();                     }                     catch (Exception ex)                     {                         throw ex;                     }                 }                 else                 {                     throw new Exception("Did not receive the messages");                 }             }             return Order;         }     } } I will post a link to the download demo in a separate post soon.

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• Using HTML 5 SessionState to save rendered Page Content

  - by Rick Strahl

  HTML 5 SessionState and LocalStorage are very useful and super easy to use to manage client side state. For building rich client side or SPA style applications it's a vital feature to be able to cache user data as well as HTML content in order to swap pages in and out of the browser's DOM. What might not be so obvious is that you can also use the sessionState and localStorage objects even in classic server rendered HTML applications to provide caching features between pages. These APIs have been around for a long time and are supported by most relatively modern browsers and even all the way back to IE8, so you can use them safely in your Web applications. SessionState and LocalStorage are easy The APIs that make up sessionState and localStorage are very simple. Both object feature the same API interface which  is a simple, string based key value store that has getItem, setItem, removeitem, clear and  key methods. The objects are also pseudo array objects and so can be iterated like an array with  a length property and you have array indexers to set and get values with. Basic usage  for storing and retrieval looks like this (using sessionStorage, but the syntax is the same for localStorage - just switch the objects):// set var lastAccess = new Date().getTime(); if (sessionStorage) sessionStorage.setItem("myapp_time", lastAccess.toString()); // retrieve in another page or on a refresh var time = null; if (sessionStorage) time = sessionStorage.getItem("myapp_time"); if (time) time = new Date(time * 1); else time = new Date(); sessionState stores data that is browser session specific and that has a liftetime of the active browser session or window. Shut down the browser or tab and the storage goes away. localStorage uses the same API interface, but the lifetime of the data is permanently stored in the browsers storage area until deleted via code or by clearing out browser cookies (not the cache). Both sessionStorage and localStorage space is limited. The spec is ambiguous about this - supposedly sessionStorage should allow for unlimited size, but it appears that most WebKit browsers support only 2.5mb for either object. This means you have to be careful what you store especially since other applications might be running on the same domain and also use the storage mechanisms. That said 2.5mb worth of character data is quite a bit and would go a long way. The easiest way to get a feel for how sessionState and localStorage work is to look at a simple example. You can go check out the following example online in Plunker: http://plnkr.co/edit/0ICotzkoPjHaWa70GlRZ?p=preview which looks like this: Plunker is an online HTML/JavaScript editor that lets you write and run Javascript code and similar to JsFiddle, but a bit cleaner to work in IMHO (thanks to John Papa for turning me on to it). The sample has two text boxes with counts that update session/local storage every time you click the related button. The counts are 'cached' in Session and Local storage. The point of these examples is that both counters survive full page reloads, and the LocalStorage counter survives a complete browser shutdown and restart. Go ahead and try it out by clicking the Reload button after updating both counters and then shutting down the browser completely and going back to the same URL (with the same browser). What you should see is that reloads leave both counters intact at the counted values, while a browser restart will leave only the local storage counter intact. The code to deal with the SessionStorage (and LocalStorage not shown here) in the example is isolated into a couple of wrapper methods to simplify the code: function getSessionCount() { var count = 0; if (sessionStorage) { var count = sessionStorage.getItem("ss_count"); count = !count ? 0 : count * 1; } $("#txtSession").val(count); return count; } function setSessionCount(count) { if (sessionStorage) sessionStorage.setItem("ss_count", count.toString()); } These two functions essentially load and store a session counter value. The two key methods used here are: sessionStorage.getItem(key); sessionStorage.setItem(key,stringVal); Note that the value given to setItem and return by getItem has to be a string. If you pass another type you get an error. Don't let that limit you though - you can easily enough store JSON data in a variable so it's quite possible to pass complex objects and store them into a single sessionStorage value:var user = { name: "Rick", id="ricks", level=8 } sessionStorage.setItem("app_user",JSON.stringify(user)); to retrieve it:var user = sessionStorage.getItem("app_user"); if (user) user = JSON.parse(user); Simple! If you're using the Chrome Developer Tools (F12) you can also check out the session and local storage state on the Resource tab:   You can also use this tool to refresh or remove entries from storage. What we just looked at is a purely client side implementation where a couple of counters are stored. For rich client centric AJAX applications sessionStorage and localStorage provide a very nice and simple API to store application state while the application is running. But you can also use these storage mechanisms to manage server centric HTML applications when you combine server rendering with some JavaScript to perform client side data caching. You can both store some state information and data on the client (ie. store a JSON object and carry it forth between server rendered HTML requests) or you can use it for good old HTTP based caching where some rendered HTML is saved and then restored later. Let's look at the latter with a real life example. Why do I need Client-side Page Caching for Server Rendered HTML? I don't know about you, but in a lot of my existing server driven applications I have lists that display a fair amount of data. Typically these lists contain links to then drill down into more specific data either for viewing or editing. You can then click on a link and go off to a detail page that provides more concise content. So far so good. But now you're done with the detail page and need to get back to the list, so you click on a 'bread crumbs trail' or an application level 'back to list' button and… …you end up back at the top of the list - the scroll position, the current selection in some cases even filters conditions - all gone with the wind. You've left behind the state of the list and are starting from scratch in your browsing of the list from the top. Not cool! Sound familiar? This a pretty common scenario with server rendered HTML content where it's so common to display lists to drill into, only to lose state in the process of returning back to the original list. Look at just about any traditional forums application, or even StackOverFlow to see what I mean here. Scroll down a bit to look at a post or entry, drill in then use the bread crumbs or tab to go back… In some cases returning to the top of a list is not a big deal. On StackOverFlow that sort of works because content is turning around so quickly you probably want to actually look at the top posts. Not always though - if you're browsing through a list of search topics you're interested in and drill in there's no way back to that position. Essentially anytime you're actively browsing the items in the list, that's when state becomes important and if it's not handled the user experience can be really disrupting. Content Caching If you're building client centric SPA style applications this is a fairly easy to solve problem - you tend to render the list once and then update the page content to overlay the detail content, only hiding the list temporarily until it's used again later. It's relatively easy to accomplish this simply by hiding content on the page and later making it visible again. But if you use server rendered content, hanging on to all the detail like filters, selections and scroll position is not quite as easy. Or is it??? This is where sessionStorage comes in handy. What if we just save the rendered content of a previous page, and then restore it when we return to this page based on a special flag that tells us to use the cached version? Let's see how we can do this. A real World Use Case Recently my local ISP asked me to help out with updating an ancient classifieds application. They had a very busy, local classifieds app that was originally an ASP classic application. The old app was - wait for it: frames based - and even though I lobbied against it, the decision was made to keep the frames based layout to allow rapid browsing of the hundreds of posts that are made on a daily basis. The primary reason they wanted this was precisely for the ability to quickly browse content item by item. While I personally hate working with Frames, I have to admit that the UI actually works well with the frames layout as long as you're running on a large desktop screen. You can check out the frames based desktop site here: http://classifieds.gorge.net/ However when I rebuilt the app I also added a secondary view that doesn't use frames. The main reason for this of course was for mobile displays which work horribly with frames. So there's a somewhat mobile friendly interface to the interface, which ditches the frames and uses some responsive design tweaking for mobile capable operation: http://classifeds.gorge.net/mobile  (or browse the base url with your browser width under 800px)   Here's what the mobile, non-frames view looks like:   As you can see this means that the list of classifieds posts now is a list and there's a separate page for drilling down into the item. And of course… originally we ran into that usability issue I mentioned earlier where the browse, view detail, go back to the list cycle resulted in lost list state. Originally in mobile mode you scrolled through the list, found an item to look at and drilled in to display the item detail. Then you clicked back to the list and BAM - you've lost your place. Because there are so many items added on a daily basis the full list is never fully loaded, but rather there's a "Load Additional Listings"  entry at the button. Not only did we originally lose our place when coming back to the list, but any 'additionally loaded' items are no longer there because the list was now rendering  as if it was the first page hit. The additional listings, and any filters, the selection of an item all were lost. Major Suckage! Using Client SessionStorage to cache Server Rendered Content To work around this problem I decided to cache the rendered page content from the list in SessionStorage. Anytime the list renders or is updated with Load Additional Listings, the page HTML is cached and stored in Session Storage. Any back links from the detail page or the login or write entry forms then point back to the list page with a back=true query string parameter. If the server side sees this parameter it doesn't render the part of the page that is cached. Instead the client side code retrieves the data from the sessionState cache and simply inserts it into the page. It sounds pretty simple, and the overall the process is really easy, but there are a few gotchas that I'll discuss in a minute. But first let's look at the implementation. Let's start with the server side here because that'll give a quick idea of the doc structure. As I mentioned the server renders data from an ASP.NET MVC view. On the list page when returning to the list page from the display page (or a host of other pages) looks like this: https://classifieds.gorge.net/list?back=True The query string value is a flag, that indicates whether the server should render the HTML. Here's what the top level MVC Razor view for the list page looks like:@model MessageListViewModel @{ ViewBag.Title = "Classified Listing"; bool isBack = !string.IsNullOrEmpty(Request.QueryString["back"]); } <form method="post" action="@Url.Action("list")"> <div id="SizingContainer"> @if (!isBack) { @Html.Partial("List_CommandBar_Partial", Model) <div id="PostItemContainer" class="scrollbox" xstyle="-webkit-overflow-scrolling: touch;"> @Html.Partial("List_Items_Partial", Model) @if (Model.RequireLoadEntry) { <div class="postitem loadpostitems" style="padding: 15px;"> <div id="LoadProgress" class="smallprogressright"></div> <div class="control-progress"> Load additional listings... </div> </div> } </div> } </div> </form> As you can see the query string triggers a conditional block that if set is simply not rendered. The content inside of #SizingContainer basically holds  the entire page's HTML sans the headers and scripts, but including the filter options and menu at the top. In this case this makes good sense - in other situations the fact that the menu or filter options might be dynamically updated might make you only cache the list rather than essentially the entire page. In this particular instance all of the content works and produces the proper result as both the list along with any filter conditions in the form inputs are restored. Ok, let's move on to the client. On the client there are two page level functions that deal with saving and restoring state. Like the counter example I showed earlier, I like to wrap the logic to save and restore values from sessionState into a separate function because they are almost always used in several places.page.saveData = function(id) { if (!sessionStorage) return; var data = { id: id, scroll: $("#PostItemContainer").scrollTop(), html: $("#SizingContainer").html() }; sessionStorage.setItem("list_html",JSON.stringify(data)); }; page.restoreData = function() { if (!sessionStorage) return; var data = sessionStorage.getItem("list_html"); if (!data) return null; return JSON.parse(data); }; The data that is saved is an object which contains an ID which is the selected element when the user clicks and a scroll position. These two values are used to reset the scroll position when the data is used from the cache. Finally the html from the #SizingContainer element is stored, which makes for the bulk of the document's HTML. In this application the HTML captured could be a substantial bit of data. If you recall, I mentioned that the server side code renders a small chunk of data initially and then gets more data if the user reads through the first 50 or so items. The rest of the items retrieved can be rather sizable. Other than the JSON deserialization that's Ok. Since I'm using SessionStorage the storage space has no immediate limits. Next is the core logic to handle saving and restoring the page state. At first though this would seem pretty simple, and in some cases it might be, but as the following code demonstrates there are a few gotchas to watch out for. Here's the relevant code I use to save and restore:$( function() { … var isBack = getUrlEncodedKey("back", location.href); if (isBack) { // remove the back key from URL setUrlEncodedKey("back", "", location.href); var data = page.restoreData(); // restore from sessionState if (!data) { // no data - force redisplay of the server side default list window.location = "list"; return; } $("#SizingContainer").html(data.html); var el = $(".postitem[data-id=" + data.id + "]"); $(".postitem").removeClass("highlight"); el.addClass("highlight"); $("#PostItemContainer").scrollTop(data.scroll); setTimeout(function() { el.removeClass("highlight"); }, 2500); } else if (window.noFrames) page.saveData(null); // save when page loads $("#SizingContainer").on("click", ".postitem", function() { var id = $(this).attr("data-id"); if (!id) return true; if (window.noFrames) page.saveData(id); var contentFrame = window.parent.frames["Content"]; if (contentFrame) contentFrame.location.href = "show/" + id; else window.location.href = "show/" + id; return false; }); … The code starts out by checking for the back query string flag which triggers restoring from the client cache. If cached the cached data structure is read from sessionStorage. It's important here to check if data was returned. If the user had back=true on the querystring but there is no cached data, he likely bookmarked this page or otherwise shut down the browser and came back to this URL. In that case the server didn't render any detail and we have no cached data, so all we can do is redirect to the original default list view using window.location. If we continued the page would render no data - so make sure to always check the cache retrieval result. Always! If there is data the it's loaded and the data.html data is restored back into the document by simply injecting the HTML back into the document's #SizingContainer element:$("#SizingContainer").html(data.html); It's that simple and it's quite quick even with a fully loaded list of additional items and on a phone. The actual HTML data is stored to the cache on every page load initially and then again when the user clicks on an element to navigate to a particular listing. The former ensures that the client cache always has something in it, and the latter updates with additional information for the selected element. For the click handling I use a data-id attribute on the list item (.postitem) in the list and retrieve the id from that. That id is then used to navigate to the actual entry as well as storing that Id value in the saved cached data. The id is used to reset the selection by searching for the data-id value in the restored elements. The overall process of this save/restore process is pretty straight forward and it doesn't require a bunch of code, yet it yields a huge improvement in the usability of the site on mobile devices (or anybody who uses the non-frames view). Some things to watch out for As easy as it conceptually seems to simply store and retrieve cached content, you have to be quite aware what type of content you are caching. The code above is all that's specific to cache/restore cycle and it works, but it took a few tweaks to the rest of the script code and server code to make it all work. There were a few gotchas that weren't immediately obvious. Here are a few things to pay attention to: Event Handling Logic Timing of manipulating DOM events Inline Script Code Bookmarking to the Cache Url when no cache exists Do you have inline script code in your HTML? That script code isn't going to run if you restore from cache and simply assign or it may not run at the time you think it would normally in the DOM rendering cycle. JavaScript Event Hookups The biggest issue I ran into with this approach almost immediately is that originally I had various static event handlers hooked up to various UI elements that are now cached. If you have an event handler like:$("#btnSearch").click( function() {…}); that works fine when the page loads with server rendered HTML, but that code breaks when you now load the HTML from cache. Why? Because the elements you're trying to hook those events to may not actually be there - yet. Luckily there's an easy workaround for this by using deferred events. With jQuery you can use the .on() event handler instead:$("#SelectionContainer").on("click","#btnSearch", function() {…}); which monitors a parent element for the events and checks for the inner selector elements to handle events on. This effectively defers to runtime event binding, so as more items are added to the document bindings still work. For any cached content use deferred events. Timing of manipulating DOM Elements Along the same lines make sure that your DOM manipulation code follows the code that loads the cached content into the page so that you don't manipulate DOM elements that don't exist just yet. Ideally you'll want to check for the condition to restore cached content towards the top of your script code, but that can be tricky if you have components or other logic that might not all run in a straight line. Inline Script Code Here's another small problem I ran into: I use a DateTime Picker widget I built a while back that relies on the jQuery date time picker. I also created a helper function that allows keyboard date navigation into it that uses JavaScript logic. Because MVC's limited 'object model' the only way to embed widget content into the page is through inline script. This code broken when I inserted the cached HTML into the page because the script code was not available when the component actually got injected into the page. As the last bullet - it's a matter of timing. There's no good work around for this - in my case I pulled out the jQuery date picker and relied on native <input type="date" /> logic instead - a better choice these days anyway, especially since this view is meant to be primarily to serve mobile devices which actually support date input through the browser (unlike desktop browsers of which only WebKit seems to support it). Bookmarking Cached Urls When you cache HTML content you have to make a decision whether you cache on the client and also not render that same content on the server. In the Classifieds app I didn't render server side content so if the user comes to the page with back=True and there is no cached content I have to a have a Plan B. Typically this happens when somebody ends up bookmarking the back URL. The easiest and safest solution for this scenario is to ALWAYS check the cache result to make sure it exists and if not have a safe URL to go back to - in this case to the plain uncached list URL which amounts to effectively redirecting. This seems really obvious in hindsight, but it's easy to overlook and not see a problem until much later, when it's not obvious at all why the page is not rendering anything. Don't use <body> to replace Content Since we're practically replacing all the HTML in the page it may seem tempting to simply replace the HTML content of the <body> tag. Don't. The body tag usually contains key things that should stay in the page and be there when it loads. Specifically script tags and elements and possibly other embedded content. It's best to create a top level DOM element specifically as a placeholder container for your cached content and wrap just around the actual content you want to replace. In the app above the #SizingContainer is that container. Other Approaches The approach I've used for this application is kind of specific to the existing server rendered application we're running and so it's just one approach you can take with caching. However for server rendered content caching this is a pattern I've used in a few apps to retrofit some client caching into list displays. In this application I took the path of least resistance to the existing server rendering logic. Here are a few other ways that come to mind: Using Partial HTML Rendering via AJAXInstead of rendering the page initially on the server, the page would load empty and the client would render the UI by retrieving the respective HTML and embedding it into the page from a Partial View. This effectively makes the initial rendering and the cached rendering logic identical and removes the server having to decide whether this request needs to be rendered or not (ie. not checking for a back=true switch). All the logic related to caching is made on the client in this case. Using JSON Data and Client RenderingThe hardcore client option is to do the whole UI SPA style and pull data from the server and then use client rendering or databinding to pull the data down and render using templates or client side databinding with knockout/angular et al. As with the Partial Rendering approach the advantage is that there's no difference in the logic between pulling the data from cache or rendering from scratch other than the initial check for the cache request. Of course if the app is a  full on SPA app, then caching may not be required even - the list could just stay in memory and be hidden and reactivated. I'm sure there are a number of other ways this can be handled as well especially using  AJAX. AJAX rendering might simplify the logic, but it also complicates search engine optimization since there's no content loaded initially. So there are always tradeoffs and it's important to look at all angles before deciding on any sort of caching solution in general. State of the Session SessionState and LocalStorage are easy to use in client code and can be integrated even with server centric applications to provide nice caching features of content and data. In this post I've shown a very specific scenario of storing HTML content for the purpose of remembering list view data and state and making the browsing experience for lists a bit more friendly, especially if there's dynamically loaded content involved. If you haven't played with sessionStorage or localStorage I encourage you to give it a try. There's a lot of cool stuff that you can do with this beyond the specific scenario I've covered here… Resources Overview of localStorage (also applies to sessionStorage) Web Storage Compatibility Modernizr Test Suite© Rick Strahl, West Wind Technologies, 2005-2013Posted in JavaScript  HTML5  ASP.NET  MVC   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• Understanding LINQ to SQL (11) Performance

  - by Dixin

  [LINQ via C# series] LINQ to SQL has a lot of great features like strong typing query compilation deferred execution declarative paradigm etc., which are very productive. Of course, these cannot be free, and one price is the performance. O/R mapping overhead Because LINQ to SQL is based on O/R mapping, one obvious overhead is, data changing usually requires data retrieving:private static void UpdateProductUnitPrice(int id, decimal unitPrice) { using (NorthwindDataContext database = new NorthwindDataContext()) { Product product = database.Products.Single(item => item.ProductID == id); // SELECT... product.UnitPrice = unitPrice; // UPDATE... database.SubmitChanges(); } } Before updating an entity, that entity has to be retrieved by an extra SELECT query. This is slower than direct data update via ADO.NET:private static void UpdateProductUnitPrice(int id, decimal unitPrice) { using (SqlConnection connection = new SqlConnection( "Data Source=localhost;Initial Catalog=Northwind;Integrated Security=True")) using (SqlCommand command = new SqlCommand( @"UPDATE [dbo].[Products] SET [UnitPrice] = @UnitPrice WHERE [ProductID] = @ProductID", connection)) { command.Parameters.Add("@ProductID", SqlDbType.Int).Value = id; command.Parameters.Add("@UnitPrice", SqlDbType.Money).Value = unitPrice; connection.Open(); command.Transaction = connection.BeginTransaction(); command.ExecuteNonQuery(); // UPDATE... command.Transaction.Commit(); } } The above imperative code specifies the “how to do” details with better performance. For the same reason, some articles from Internet insist that, when updating data via LINQ to SQL, the above declarative code should be replaced by:private static void UpdateProductUnitPrice(int id, decimal unitPrice) { using (NorthwindDataContext database = new NorthwindDataContext()) { database.ExecuteCommand( "UPDATE [dbo].[Products] SET [UnitPrice] = {0} WHERE [ProductID] = {1}", id, unitPrice); } } Or just create a stored procedure:CREATE PROCEDURE [dbo].[UpdateProductUnitPrice] ( @ProductID INT, @UnitPrice MONEY ) AS BEGIN BEGIN TRANSACTION UPDATE [dbo].[Products] SET [UnitPrice] = @UnitPrice WHERE [ProductID] = @ProductID COMMIT TRANSACTION END and map it as a method of NorthwindDataContext (explained in this post):private static void UpdateProductUnitPrice(int id, decimal unitPrice) { using (NorthwindDataContext database = new NorthwindDataContext()) { database.UpdateProductUnitPrice(id, unitPrice); } } As a normal trade off for O/R mapping, a decision has to be made between performance overhead and programming productivity according to the case. In a developer’s perspective, if O/R mapping is chosen, I consistently choose the declarative LINQ code, unless this kind of overhead is unacceptable. Data retrieving overhead After talking about the O/R mapping specific issue. Now look into the LINQ to SQL specific issues, for example, performance in the data retrieving process. The previous post has explained that the SQL translating and executing is complex. Actually, the LINQ to SQL pipeline is similar to the compiler pipeline. It consists of about 15 steps to translate an C# expression tree to SQL statement, which can be categorized as: Convert: Invoke SqlProvider.BuildQuery() to convert the tree of Expression nodes into a tree of SqlNode nodes; Bind: Used visitor pattern to figure out the meanings of names according to the mapping info, like a property for a column, etc.; Flatten: Figure out the hierarchy of the query; Rewrite: for SQL Server 2000, if needed Reduce: Remove the unnecessary information from the tree. Parameterize Format: Generate the SQL statement string; Parameterize: Figure out the parameters, for example, a reference to a local variable should be a parameter in SQL; Materialize: Executes the reader and convert the result back into typed objects. So for each data retrieving, even for data retrieving which looks simple: private static Product[] RetrieveProducts(int productId) { using (NorthwindDataContext database = new NorthwindDataContext()) { return database.Products.Where(product => product.ProductID == productId) .ToArray(); } } LINQ to SQL goes through above steps to translate and execute the query. Fortunately, there is a built-in way to cache the translated query. Compiled query When such a LINQ to SQL query is executed repeatedly, The CompiledQuery can be used to translate query for one time, and execute for multiple times:internal static class CompiledQueries { private static readonly Func<NorthwindDataContext, int, Product[]> _retrieveProducts = CompiledQuery.Compile((NorthwindDataContext database, int productId) => database.Products.Where(product => product.ProductID == productId).ToArray()); internal static Product[] RetrieveProducts( this NorthwindDataContext database, int productId) { return _retrieveProducts(database, productId); } } The new version of RetrieveProducts() gets better performance, because only when _retrieveProducts is first time invoked, it internally invokes SqlProvider.Compile() to translate the query expression. And it also uses lock to make sure translating once in multi-threading scenarios. Static SQL / stored procedures without translating Another way to avoid the translating overhead is to use static SQL or stored procedures, just as the above examples. Because this is a functional programming series, this article not dive into. For the details, Scott Guthrie already has some excellent articles: LINQ to SQL (Part 6: Retrieving Data Using Stored Procedures) LINQ to SQL (Part 7: Updating our Database using Stored Procedures) LINQ to SQL (Part 8: Executing Custom SQL Expressions) Data changing overhead By looking into the data updating process, it also needs a lot of work: Begins transaction Processes the changes (ChangeProcessor) Walks through the objects to identify the changes Determines the order of the changes Executes the changings LINQ queries may be needed to execute the changings, like the first example in this article, an object needs to be retrieved before changed, then the above whole process of data retrieving will be went through If there is user customization, it will be executed, for example, a table’s INSERT / UPDATE / DELETE can be customized in the O/R designer It is important to keep these overhead in mind. Bulk deleting / updating Another thing to be aware is the bulk deleting:private static void DeleteProducts(int categoryId) { using (NorthwindDataContext database = new NorthwindDataContext()) { database.Products.DeleteAllOnSubmit( database.Products.Where(product => product.CategoryID == categoryId)); database.SubmitChanges(); } } The expected SQL should be like:BEGIN TRANSACTION exec sp_executesql N'DELETE FROM [dbo].[Products] AS [t0] WHERE [t0].[CategoryID] = @p0',N'@p0 int',@p0=9 COMMIT TRANSACTION Hoverer, as fore mentioned, the actual SQL is to retrieving the entities, and then delete them one by one:-- Retrieves the entities to be deleted: exec sp_executesql N'SELECT [t0].[ProductID], [t0].[ProductName], [t0].[SupplierID], [t0].[CategoryID], [t0].[QuantityPerUnit], [t0].[UnitPrice], [t0].[UnitsInStock], [t0].[UnitsOnOrder], [t0].[ReorderLevel], [t0].[Discontinued] FROM [dbo].[Products] AS [t0] WHERE [t0].[CategoryID] = @p0',N'@p0 int',@p0=9 -- Deletes the retrieved entities one by one: BEGIN TRANSACTION exec sp_executesql N'DELETE FROM [dbo].[Products] WHERE ([ProductID] = @p0) AND ([ProductName] = @p1) AND ([SupplierID] IS NULL) AND ([CategoryID] = @p2) AND ([QuantityPerUnit] IS NULL) AND ([UnitPrice] = @p3) AND ([UnitsInStock] = @p4) AND ([UnitsOnOrder] = @p5) AND ([ReorderLevel] = @p6) AND (NOT ([Discontinued] = 1))',N'@p0 int,@p1 nvarchar(4000),@p2 int,@p3 money,@p4 smallint,@p5 smallint,@p6 smallint',@p0=78,@p1=N'Optimus Prime',@p2=9,@p3=$0.0000,@p4=0,@p5=0,@p6=0 exec sp_executesql N'DELETE FROM [dbo].[Products] WHERE ([ProductID] = @p0) AND ([ProductName] = @p1) AND ([SupplierID] IS NULL) AND ([CategoryID] = @p2) AND ([QuantityPerUnit] IS NULL) AND ([UnitPrice] = @p3) AND ([UnitsInStock] = @p4) AND ([UnitsOnOrder] = @p5) AND ([ReorderLevel] = @p6) AND (NOT ([Discontinued] = 1))',N'@p0 int,@p1 nvarchar(4000),@p2 int,@p3 money,@p4 smallint,@p5 smallint,@p6 smallint',@p0=79,@p1=N'Bumble Bee',@p2=9,@p3=$0.0000,@p4=0,@p5=0,@p6=0 -- ... COMMIT TRANSACTION And the same to the bulk updating. This is really not effective and need to be aware. Here is already some solutions from the Internet, like this one. The idea is wrap the above SELECT statement into a INNER JOIN:exec sp_executesql N'DELETE [dbo].[Products] FROM [dbo].[Products] AS [j0] INNER JOIN ( SELECT [t0].[ProductID], [t0].[ProductName], [t0].[SupplierID], [t0].[CategoryID], [t0].[QuantityPerUnit], [t0].[UnitPrice], [t0].[UnitsInStock], [t0].[UnitsOnOrder], [t0].[ReorderLevel], [t0].[Discontinued] FROM [dbo].[Products] AS [t0] WHERE [t0].[CategoryID] = @p0) AS [j1] ON ([j0].[ProductID] = [j1].[[Products])', -- The Primary Key N'@p0 int',@p0=9 Query plan overhead The last thing is about the SQL Server query plan. Before .NET 4.0, LINQ to SQL has an issue (not sure if it is a bug). LINQ to SQL internally uses ADO.NET, but it does not set the SqlParameter.Size for a variable-length argument, like argument of NVARCHAR type, etc. So for two queries with the same SQL but different argument length:using (NorthwindDataContext database = new NorthwindDataContext()) { database.Products.Where(product => product.ProductName == "A") .Select(product => product.ProductID).ToArray(); // The same SQL and argument type, different argument length. database.Products.Where(product => product.ProductName == "AA") .Select(product => product.ProductID).ToArray(); } Pay attention to the argument length in the translated SQL:exec sp_executesql N'SELECT [t0].[ProductID] FROM [dbo].[Products] AS [t0] WHERE [t0].[ProductName] = @p0',N'@p0 nvarchar(1)',@p0=N'A' exec sp_executesql N'SELECT [t0].[ProductID] FROM [dbo].[Products] AS [t0] WHERE [t0].[ProductName] = @p0',N'@p0 nvarchar(2)',@p0=N'AA' Here is the overhead: The first query’s query plan cache is not reused by the second one:SELECT sys.syscacheobjects.cacheobjtype, sys.dm_exec_cached_plans.usecounts, sys.syscacheobjects.[sql] FROM sys.syscacheobjects INNER JOIN sys.dm_exec_cached_plans ON sys.syscacheobjects.bucketid = sys.dm_exec_cached_plans.bucketid; They actually use different query plans. Again, pay attention to the argument length in the [sql] column (@p0 nvarchar(2) / @p0 nvarchar(1)). Fortunately, in .NET 4.0 this is fixed:internal static class SqlTypeSystem { private abstract class ProviderBase : TypeSystemProvider { protected int? GetLargestDeclarableSize(SqlType declaredType) { SqlDbType sqlDbType = declaredType.SqlDbType; if (sqlDbType <= SqlDbType.Image) { switch (sqlDbType) { case SqlDbType.Binary: case SqlDbType.Image: return 8000; } return null; } if (sqlDbType == SqlDbType.NVarChar) { return 4000; // Max length for NVARCHAR. } if (sqlDbType != SqlDbType.VarChar) { return null; } return 8000; } } } In this above example, the translated SQL becomes:exec sp_executesql N'SELECT [t0].[ProductID] FROM [dbo].[Products] AS [t0] WHERE [t0].[ProductName] = @p0',N'@p0 nvarchar(4000)',@p0=N'A' exec sp_executesql N'SELECT [t0].[ProductID] FROM [dbo].[Products] AS [t0] WHERE [t0].[ProductName] = @p0',N'@p0 nvarchar(4000)',@p0=N'AA' So that they reuses the same query plan cache: Now the [usecounts] column is 2.

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• SQL SERVER – Weekly Series – Memory Lane – #051

  - 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 Explanation and Understanding NOT NULL Constraint NOT NULL is integrity CONSTRAINT. It does not allow creating of the row where column contains NULL value. Most discussed questions about NULL is what is NULL? I will not go in depth analysis it. Simply put NULL is unknown or missing data. When NULL is present in database columns, it can affect the integrity of the database. I really do not prefer NULL in the database unless they are absolutely necessary. Three T-SQL Script to Create Primary Keys on Table I have always enjoyed writing about three topics Constraint and Keys, Backup and Restore and Datetime Functions. Primary Keys constraints prevent duplicate values for columns and provides a unique identifier to each column, as well it creates clustered index on the columns. 2008 Get Numeric Value From Alpha Numeric String – UDF for Get Numeric Numbers Only SQL is great with String operations. Many times, I use T-SQL to do my string operation. Let us see User Defined Function, which I wrote a few days ago, which will return only Numeric values from Alpha Numeric values. Introduction and Example of UNION and UNION ALL It is very much interesting when I get requests from blog reader to re-write my previous articles. I have received few requests to rewrite my article SQL SERVER – Union vs. Union All – Which is better for performance? with examples. I request you to read my previous article first to understand what is the concept and read this article to understand the same concept with an example. Downgrade Database for Previous Version The main questions is how they can downgrade the from SQL Server 2005 to SQL Server 2000? The answer is : Not Possible. Get Common Records From Two Tables Without Using Join Following is my scenario, Suppose Table 1 and Table 2 has same column e.g. Column1 Following is the query, 1. Select column1,column2 From Table1 2. Select column1 From Table2 I want to find common records from these tables, but I don’t want to use the Join clause because for that I need to specify the column name for Join condition. Will you help me to get common records without using Join condition? I am using SQL Server 2005. Retrieve – Select Only Date Part From DateTime – Best Practice – Part 2 A year ago I wrote a post about SQL SERVER – Retrieve – Select Only Date Part From DateTime – Best Practice where I have discussed two different methods of getting the date part from datetime. Introduction to CLR – Simple Example of CLR Stored Procedure CLR is an abbreviation of Common Language Runtime. In SQL Server 2005 and later version of it database objects can be created which are created in CLR. Stored Procedures, Functions, Triggers can be coded in CLR. CLR is faster than T-SQL in many cases. CLR is mainly used to accomplish tasks which are not possible by T-SQL or can use lots of resources. The CLR can be usually implemented where there is an intense string operation, thread management or iteration methods which can be complicated for T-SQL. Implementing CLR provides more security to the Extended Stored Procedure. 2009 Comic Slow Query – SQL Joke Before Presentation After Presentation Enable Automatic Statistic Update on Database In one of the recent projects, I found out that despite putting good indexes and optimizing the query, I could not achieve an optimized performance and I still received an unoptimized response from the SQL Server. On examination, I figured out that the culprit was statistics. The database that I was trying to optimize had auto update of the statistics was disabled. Recently Executed T-SQL Query Please refer to blog post  query to recently executed T-SQL query on database. Change Collation of Database Column – T-SQL Script – Consolidating Collations – Extention Script At some time in your DBA career, you may find yourself in a position when you sit back and realize that your database collations have somehow run amuck, or are faced with the ever annoying CANNOT RESOLVE COLLATION message when trying to join data of varying collation settings. 2010 Visiting Alma Mater – Delivering Session on Database Performance and Career – Nirma Institute of Technology Everyone always dreams of visiting their school and college, where they have studied once. It is a great feeling to see the college once again – where you have spent the wonderful golden years of your time. College time is filled with studies, education, emotions and several plans to build a future. I consider myself fortunate as I got the opportunity to study at some of the best places in the world. Change Column DataTypes There are times when I feel like writing that I am a day older in SQL Server. In fact, there are many who are looking for a solution that is simple enough. Have you ever searched online for something very simple. I often do and enjoy doing things which are straight forward and easy to change. 2011 Three DMVs – sys.dm_server_memory_dumps – sys.dm_server_services – sys.dm_server_registry In this blog post we will see three new DMVs which are introduced in Denali. The DMVs are very simple and there is not much to describe them. So here is the simple game. I will be asking a question back to you after seeing the result of the each of the DMV and you help me to complete this blog post. A Simple Quiz – T-SQL Brain Trick If you have some time, I strongly suggest you try this quiz out as it is for sure twists your brain. 2012 List All The Column With Specific Data Types in Database 5 years ago I wrote script SQL SERVER – 2005 – List All The Column With Specific Data Types, when I read it again, it is very much relevant and I liked it. This is one of the script which every developer would like to keep it handy. I have upgraded the script bit more. I have included few additional information which I believe I should have added from the beginning. It is difficult to visualize the final script when we are writing it first time. Find First Non-Numeric Character from String The function PATINDEX exists for quite a long time in SQL Server but I hardly see it being used. Well, at least I use it and I am comfortable using it. Here is a simple script which I use when I have to identify first non-numeric character. Finding Different ColumnName From Almost Identitical Tables Well here is the interesting example of how we can use sys.column catalogue views and get the details of the newly added column. I have previously written about EXCEPT over here which is very similar to MINUS of Oracle. Storing Data and Files in Cloud – Dropbox – Personal Technology Tip I thought long and hard about doing a Personal Technology Tips series for this blog.  I have so many tips I’d like to share.  I am on my computer almost all day, every day, so I have a treasure trove of interesting tidbits I like to share if given the chance.  The only thing holding me back – which tip to share first?  The first tip obviously has the weight of seeming like the most important.  But this would mean choosing amongst my favorite tricks and shortcuts.  This is a hard task. 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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• Segmentation Fault (11) with modwsgi on CentOS 5.7 when running pyramid app

  - by carbotex

  I'm getting Segmentation fault error when trying to access the "Hello World" pyramid app. This error only occurs when running against CentOS 5.7 setup, but no problem whatsoever when tested against OSX and Arch Linux. Could it be a CentOS specific issue? [error] [client 10.211.55.2] Premature end of script headers: pyramid.wsgi [notice] child pid 31212 exit signal Segmentation fault (11) I have tried to follow the troubleshooting guides posted here http://code.google.com/p/modwsgi/wiki/InstallationIssues which suggests that it might caused by missing Shared Library. A quick check reveals that shared library is not the issue. [centos57@localhost modules]$ ldd mod_wsgi.so linux-gate.so.1 => (0x00e6a000) libpython2.7.so.1.0 => /home/python/lib/libpython2.7.so.1.0 (0x0024c000) libpthread.so.0 => /lib/libpthread.so.0 (0x00da8000) libdl.so.2 => /lib/libdl.so.2 (0x00cd6000) libutil.so.1 => /lib/libutil.so.1 (0x00110000) libm.so.6 => /lib/libm.so.6 (0x0085c000) libc.so.6 => /lib/libc.so.6 (0x00682000) /lib/ld-linux.so.2 (0x0012b000) Then I found another clue that might be able to solve my problem. Unfortunately libexpat is not the source of the problem. http://code.google.com/p/modwsgi/wiki/IssuesWithExpatLibrary [centos57@localhost bin]$ ldd ~/httpd/bin/httpd | grep expat libexpat.so.1 => /usr/local/lib/libexpat.so.1 (0x00b00000) [centos57@localhost bin]$ strings /usr/local/lib/libexpat.so.1 | grep expat libexpat.so.1 expat_2.0.1 [centos57@localhost bin]$ python Python 2.7.2 (default, Nov 26 2011, 08:08:44) [GCC 4.1.2 20080704 (Red Hat 4.1.2-51)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import pyexpat >>> pyexpat.version_info (2, 0, 0) >>> I've been pulling my hair out trying to figure out what I'm missing in my setup. Why the problem only occurs with CentOS? Here is the detailed setup: Apache 2.2.19 Python 2.7.2 mod_wsgi-3.3 /home/httpd/conf/extra/pyramid.wsgi from pyramid.paster import get_app application = get_app('/home/homecamera/hcadmin/root/production.ini', 'main') /home/httpd/conf/extra/modwsgi.conf LoadModule wsgi_module modules/mod_wsgi.so WSGIScriptAlias /myapp /home/root/test.wsgi <Directory /home/root> WSGIProcessGroup pyramid Order allow,deny Allow from all </Directory> # Use only 1 Python sub-interpreter. Multiple sub-interpreters # play badly with C extensions. WSGIApplicationGroup %{GLOBAL} WSGIPassAuthorization On WSGIDaemonProcess pyramid user=daemon group=daemon processes=1 \ threads=4 \ python-path=/home/python/lib/python2.7/site-packages WSGIScriptAlias /hello /home/httpd/conf/extra/pyramid.wsgi <Directory /home/httpd/conf/extra> WSGIProcessGroup pyramid Order allow,deny Allow from all </Directory> Again this same setup works on OSX and Arch Linux but not on CentOS 5.7. Could someone out there point me to the right direction before I ran out of my hair. ==================================================================================== When apache started with gdb, I got a couple of warnings Reading symbols from /home/httpd/bin/httpd...done. Attaching to program: /home/httpd/bin/httpd, process 1821 warning: .dynamic section for "/lib/libcrypt.so.1" is not at the expected address warning: difference appears to be caused by prelink, adjusting expectations warning: .dynamic section for "/lib/libutil.so.1" is not at the expected address warning: difference appears to be caused by prelink, adjusting expectations gdb output. After hitting refresh button, to load pyramid. (gdb) cont Continuing. warning: .dynamic section for "/usr/lib/libgssapi_krb5.so.2" is not at the expected address warning: difference appears to be caused by prelink, adjusting expectations warning: .dynamic section for "/usr/lib/libkrb5.so.3" is not at the expected address warning: difference appears to be caused by prelink, adjusting expectations warning: .dynamic section for "/lib/libresolv.so.2" is not at the expected address warning: difference appears to be caused by prelink, adjusting expectations Program received signal SIGSEGV, Segmentation fault. [Switching to Thread 0x8edbb90 (LWP 1824)] 0x0814c120 in EVP_PKEY_CTX_dup () apache_error_log [info] mod_wsgi (pid=1821): Starting process 'pyramid' with threads=1. [info] mod_wsgi (pid=1821): Initializing Python. [info] mod_wsgi (pid=1821): Attach interpreter ''. [info] mod_wsgi (pid=1821): Create interpreter 'web.domain.com:20000|/hcadmin'. [info] [client 10.211.55.2] mod_wsgi (pid=1821, process='pyramid', application='web.domain.com:20000|/hcadmin'): Loading WSGI script '/home/httpd/conf/extra/pyramid.wsgi'. [error] hello 1

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• Commit in SQL

  - by PRajkumar

  SQL Transaction Control Language Commands (TCL)                                           (COMMIT) Commit Transaction As a SQL language we use transaction control language very frequently. Committing a transaction means making permanent the changes performed by the SQL statements within the transaction. A transaction is a sequence of SQL statements that Oracle Database treats as a single unit. This statement also erases all save points in the transaction and releases transaction locks. Oracle Database issues an implicit COMMIT before and after any data definition language (DDL) statement. Oracle recommends that you explicitly end every transaction in your application programs with a COMMIT or ROLLBACK statement, including the last transaction, before disconnecting from Oracle Database. If you do not explicitly commit the transaction and the program terminates abnormally, then the last uncommitted transaction is automatically rolled back.   Until you commit a transaction: ·         You can see any changes you have made during the transaction by querying the modified tables, but other users cannot see the changes. After you commit the transaction, the changes are visible to other users' statements that execute after the commit ·         You can roll back (undo) any changes made during the transaction with the ROLLBACK statement   Note: Most of the people think that when we type commit data or changes of what you have made has been written to data files, but this is wrong when you type commit it means that you are saying that your job has been completed and respective verification will be done by oracle engine that means it checks whether your transaction achieved consistency when it finds ok it sends a commit message to the user from log buffer but not from data buffer, so after writing data in log buffer it insists data buffer to write data in to data files, this is how it works.   Before a transaction that modifies data is committed, the following has occurred: ·         Oracle has generated undo information. The undo information contains the old data values changed by the SQL statements of the transaction ·         Oracle has generated redo log entries in the redo log buffer of the System Global Area (SGA). The redo log record contains the change to the data block and the change to the rollback block. These changes may go to disk before a transaction is committed ·         The changes have been made to the database buffers of the SGA. These changes may go to disk before a transaction is committed   Note:   The data changes for a committed transaction, stored in the database buffers of the SGA, are not necessarily written immediately to the data files by the database writer (DBWn) background process. This writing takes place when it is most efficient for the database to do so. It can happen before the transaction commits or, alternatively, it can happen some times after the transaction commits.   When a transaction is committed, the following occurs: 1.      The internal transaction table for the associated undo table space records that the transaction has committed, and the corresponding unique system change number (SCN) of the transaction is assigned and recorded in the table 2.      The log writer process (LGWR) writes redo log entries in the SGA's redo log buffers to the redo log file. It also writes the transaction's SCN to the redo log file. This atomic event constitutes the commit of the transaction 3.      Oracle releases locks held on rows and tables 4.      Oracle marks the transaction complete   Note:   The default behavior is for LGWR to write redo to the online redo log files synchronously and for transactions to wait for the redo to go to disk before returning a commit to the user. However, for lower transaction commit latency application developers can specify that redo be written asynchronously and that transaction do not need to wait for the redo to be on disk.   The syntax of Commit Statement is   COMMIT [WORK] [COMMENT ‘your comment’]; ·         WORK is optional. The WORK keyword is supported for compliance with standard SQL. The statements COMMIT and COMMIT WORK are equivalent. Examples Committing an Insert INSERT INTO table_name VALUES (val1, val2); COMMIT WORK; ·         COMMENT Comment is also optional. This clause is supported for backward compatibility. Oracle recommends that you used named transactions instead of commit comments. Specify a comment to be associated with the current transaction. The 'text' is a quoted literal of up to 255 bytes that Oracle Database stores in the data dictionary view DBA_2PC_PENDING along with the transaction ID if a distributed transaction becomes in doubt. This comment can help you diagnose the failure of a distributed transaction. Examples The following statement commits the current transaction and associates a comment with it: COMMIT     COMMENT 'In-doubt transaction Code 36, Call (415) 555-2637'; ·         WRITE Clause Use this clause to specify the priority with which the redo information generated by the commit operation is written to the redo log. This clause can improve performance by reducing latency, thus eliminating the wait for an I/O to the redo log. Use this clause to improve response time in environments with stringent response time requirements where the following conditions apply: The volume of update transactions is large, requiring that the redo log be written to disk frequently. The application can tolerate the loss of an asynchronously committed transaction. The latency contributed by waiting for the redo log write to occur contributes significantly to overall response time. You can specify the WAIT | NOWAIT and IMMEDIATE | BATCH clauses in any order. Examples To commit the same insert operation and instruct the database to buffer the change to the redo log, without initiating disk I/O, use the following COMMIT statement: COMMIT WRITE BATCH; Note: If you omit this clause, then the behavior of the commit operation is controlled by the COMMIT_WRITE initialization parameter, if it has been set. The default value of the parameter is the same as the default for this clause. Therefore, if the parameter has not been set and you omit this clause, then commit records are written to disk before control is returned to the user. WAIT | NOWAIT Use these clauses to specify when control returns to the user. The WAIT parameter ensures that the commit will return only after the corresponding redo is persistent in the online redo log. Whether in BATCH or IMMEDIATE mode, when the client receives a successful return from this COMMIT statement, the transaction has been committed to durable media. A crash occurring after a successful write to the log can prevent the success message from returning to the client. In this case the client cannot tell whether or not the transaction committed. The NOWAIT parameter causes the commit to return to the client whether or not the write to the redo log has completed. This behavior can increase transaction throughput. With the WAIT parameter, if the commit message is received, then you can be sure that no data has been lost. Caution: With NOWAIT, a crash occurring after the commit message is received, but before the redo log record(s) are written, can falsely indicate to a transaction that its changes are persistent. If you omit this clause, then the transaction commits with the WAIT behavior. IMMEDIATE | BATCH Use these clauses to specify when the redo is written to the log. The IMMEDIATE parameter causes the log writer process (LGWR) to write the transaction's redo information to the log. This operation option forces a disk I/O, so it can reduce transaction throughput. The BATCH parameter causes the redo to be buffered to the redo log, along with other concurrently executing transactions. When sufficient redo information is collected, a disk write of the redo log is initiated. This behavior is called "group commit", as redo for multiple transactions is written to the log in a single I/O operation. If you omit this clause, then the transaction commits with the IMMEDIATE behavior. ·         FORCE Clause Use this clause to manually commit an in-doubt distributed transaction or a corrupt transaction. ·         In a distributed database system, the FORCE string [, integer] clause lets you manually commit an in-doubt distributed transaction. The transaction is identified by the 'string' containing its local or global transaction ID. To find the IDs of such transactions, query the data dictionary view DBA_2PC_PENDING. You can use integer to specifically assign the transaction a system change number (SCN). If you omit integer, then the transaction is committed using the current SCN. ·         The FORCE CORRUPT_XID 'string' clause lets you manually commit a single corrupt transaction, where string is the ID of the corrupt transaction. Query the V$CORRUPT_XID_LIST data dictionary view to find the transaction IDs of corrupt transactions. You must have DBA privileges to view the V$CORRUPT_XID_LIST and to specify this clause. ·         Specify FORCE CORRUPT_XID_ALL to manually commit all corrupt transactions. You must have DBA privileges to specify this clause. Examples Forcing an in doubt transaction. Example The following statement manually commits a hypothetical in-doubt distributed transaction. Query the V$CORRUPT_XID_LIST data dictionary view to find the transaction IDs of corrupt transactions. You must have DBA privileges to view the V$CORRUPT_XID_LIST and to issue this statement. COMMIT FORCE '22.57.53';

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• How I understood monads, part 1/2: sleepless and self-loathing in Seattle

  - by Bertrand Le Roy

  For some time now, I had been noticing some interest for monads, mostly in the form of unintelligible (to me) blog posts and comments saying “oh, yeah, that’s a monad” about random stuff as if it were absolutely obvious and if I didn’t know what they were talking about, I was probably an uneducated idiot, ignorant about the simplest and most fundamental concepts of functional programming. Fair enough, I am pretty much exactly that. Being the kind of guy who can spend eight years in college just to understand a few interesting concepts about the universe, I had to check it out and try to understand monads so that I too can say “oh, yeah, that’s a monad”. Man, was I hit hard in the face with the limitations of my own abstract thinking abilities. All the articles I could find about the subject seemed to be vaguely understandable at first but very quickly overloaded the very few concept slots I have available in my brain. They also seemed to be consistently using arcane notation that I was entirely unfamiliar with. It finally all clicked together one Friday afternoon during the team’s beer symposium when Louis was patient enough to break it down for me in a language I could understand (C#). I don’t know if being intoxicated helped. Feel free to read this with or without a drink in hand. So here it is in a nutshell: a monad allows you to manipulate stuff in interesting ways. Oh, OK, you might say. Yeah. Exactly. Let’s start with a trivial case: public static class Trivial { public static TResult Execute<T, TResult>( this T argument, Func<T, TResult> operation) { return operation(argument); } } This is not a monad. I removed most concepts here to start with something very simple. There is only one concept here: the idea of executing an operation on an object. This is of course trivial and it would actually be simpler to just apply that operation directly on the object. But please bear with me, this is our first baby step. Here’s how you use that thing: "some string" .Execute(s => s + " processed by trivial proto-monad.") .Execute(s => s + " And it's chainable!"); What we’re doing here is analogous to having an assembly chain in a factory: you can feed it raw material (the string here) and a number of machines that each implement a step in the manufacturing process and you can start building stuff. The Trivial class here represents the empty assembly chain, the conveyor belt if you will, but it doesn’t care what kind of raw material gets in, what gets out or what each machine is doing. It is pure process. A real monad will need a couple of additional concepts. Let’s say the conveyor belt needs the material to be processed to be contained in standardized boxes, just so that it can safely and efficiently be transported from machine to machine or so that tracking information can be attached to it. Each machine knows how to treat raw material or partly processed material, but it doesn’t know how to treat the boxes so the conveyor belt will have to extract the material from the box before feeding it into each machine, and it will have to box it back afterwards. This conveyor belt with boxes is essentially what a monad is. It has one method to box stuff, one to extract stuff from its box and one to feed stuff into a machine. So let’s reformulate the previous example but this time with the boxes, which will do nothing for the moment except containing stuff. public class Identity<T> { public Identity(T value) { Value = value; } public T Value { get; private set;} public static Identity<T> Unit(T value) { return new Identity<T>(value); } public static Identity<U> Bind<U>( Identity<T> argument, Func<T, Identity<U>> operation) { return operation(argument.Value); } } Now this is a true to the definition Monad, including the weird naming of the methods. It is the simplest monad, called the identity monad and of course it does nothing useful. Here’s how you use it: Identity<string>.Bind( Identity<string>.Unit("some string"), s => Identity<string>.Unit( s + " was processed by identity monad.")).Value That of course is seriously ugly. Note that the operation is responsible for re-boxing its result. That is a part of strict monads that I don’t quite get and I’ll take the liberty to lift that strange constraint in the next examples. To make this more readable and easier to use, let’s build a few extension methods: public static class IdentityExtensions { public static Identity<T> ToIdentity<T>(this T value) { return new Identity<T>(value); } public static Identity<U> Bind<T, U>( this Identity<T> argument, Func<T, U> operation) { return operation(argument.Value).ToIdentity(); } } With those, we can rewrite our code as follows: "some string".ToIdentity() .Bind(s => s + " was processed by monad extensions.") .Bind(s => s + " And it's chainable...") .Value; This is considerably simpler but still retains the qualities of a monad. But it is still pointless. Let’s look at a more useful example, the state monad, which is basically a monad where the boxes have a label. It’s useful to perform operations on arbitrary objects that have been enriched with an attached state object. public class Stateful<TValue, TState> { public Stateful(TValue value, TState state) { Value = value; State = state; } public TValue Value { get; private set; } public TState State { get; set; } } public static class StateExtensions { public static Stateful<TValue, TState> ToStateful<TValue, TState>( this TValue value, TState state) { return new Stateful<TValue, TState>(value, state); } public static Stateful<TResult, TState> Execute<TValue, TState, TResult>( this Stateful<TValue, TState> argument, Func<TValue, TResult> operation) { return operation(argument.Value) .ToStateful(argument.State); } } You can get a stateful version of any object by calling the ToStateful extension method, passing the state object in. You can then execute ordinary operations on the values while retaining the state: var statefulInt = 3.ToStateful("This is the state"); var processedStatefulInt = statefulInt .Execute(i => ++i) .Execute(i => i * 10) .Execute(i => i + 2); Console.WriteLine("Value: {0}; state: {1}", processedStatefulInt.Value, processedStatefulInt.State); This monad differs from the identity by enriching the boxes. There is another way to give value to the monad, which is to enrich the processing. An example of that is the writer monad, which can be typically used to log the operations that are being performed by the monad. Of course, the richest monads enrich both the boxes and the processing. That’s all for today. I hope with this you won’t have to go through the same process that I did to understand monads and that you haven’t gone into concept overload like I did. Next time, we’ll examine some examples that you already know but we will shine the monadic light, hopefully illuminating them in a whole new way. Realizing that this pattern is actually in many places but mostly unnoticed is what will enable the truly casual “oh, yes, that’s a monad” comments. Here’s the code for this article: http://weblogs.asp.net/blogs/bleroy/Samples/Monads.zip The Wikipedia article on monads: http://en.wikipedia.org/wiki/Monads_in_functional_programming This article was invaluable for me in understanding how to express the canonical monads in C# (interesting Linq stuff in there): http://blogs.msdn.com/b/wesdyer/archive/2008/01/11/the-marvels-of-monads.aspx

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• SQL SERVER – SSMS Automatically Generates TOP (100) PERCENT in Query Designer

  - by pinaldave

  Earlier this week, I was surfing various SQL forums to see what kind of help developer need in the SQL Server world. One of the question indeed caught my attention. I am here regenerating complete question as well scenario to illustrate the point in a precise manner. Additionally, I have added added second part of the question to give completeness. Question: I am trying to create a view in Query Designer (not in the New Query Window). Every time I am trying to create a view it always adds  TOP (100) PERCENT automatically on the T-SQL script. No matter what I do, it always automatically adds the TOP (100) PERCENT to the script. I have attempted to copy paste from notepad, build a query and a few other things – there is no success. I am really not sure what I am doing wrong with Query Designer. Here is my query script: (I use AdventureWorks as a sample database) SELECT Person.Address.AddressID FROM Person.Address INNER JOIN Person.AddressType ON Person.Address.AddressID = Person.AddressType.AddressTypeID ORDER BY Person.Address.AddressID This script automatically replaces by following query: SELECT TOP (100) PERCENT Person.Address.AddressID FROM Person.Address INNER JOIN Person.AddressType ON Person.Address.AddressID = Person.AddressType.AddressTypeID ORDER BY Person.Address.AddressID However, when I try to do the same from New Query Window it works totally fine. However, when I attempt to create a view of the same query it gives following error. Msg 1033, Level 15, State 1, Procedure myView, Line 6 The ORDER BY clause is invalid in views, inline functions, derived tables, subqueries, and common table expressions, unless TOP, OFFSET or FOR XML is also specified. It is pretty clear to me now that the script which I have written seems to need TOP (100) PERCENT, so Query . Why do I need it? Is there any work around to this issue. I particularly find this question pretty interesting as it really touches the fundamentals of the T-SQL query writing. Please note that the query which is automatically changed is not in New Query Editor but opened from SSMS using following way. Database >> Views >> Right Click >> New View (see the image below) Answer: The answer to the above question can be very long but I will keep it simple and to the point. There are three things to discuss in above script 1) Reason for Error 2) Reason for Auto generates TOP (100) PERCENT and 3) Potential solutions to the above error. Let us quickly see them in detail. 1) Reason for Error The reason for error is already given in the error. ORDER BY is invalid in the views and a few other objects. One has to use TOP or other keywords along with it. The way semantics of the query works where optimizer only follows(honors) the ORDER BY in the same scope or the same SELECT/UPDATE/DELETE statement. There is a possibility that one can order after the scope of the view again the efforts spend to order view will be wasted. The final resultset of the query always follows the final ORDER BY or outer query’s order and due to the same reason optimizer follows the final order of the query and not of the views (as view will be used in another query for further processing e.g. in SELECT statement). Due to same reason ORDER BY is now allowed in the view. For further accuracy and clear guidance I suggest you read this blog post by Query Optimizer Team. They have explained it very clear manner the same subject. 2) Reason for Auto Generated TOP (100) PERCENT One of the most popular workaround to above error is to use TOP (100) PERCENT in the view. Now TOP (100) PERCENT allows user to use ORDER BY in the query and allows user to overcome above error which we discussed. This gives the impression to the user that they have resolved the error and successfully able to use ORDER BY in the View. Well, this is incorrect as well. The way this works is when TOP (100) PERCENT is used the result is not guaranteed as well it is ignored in our the query where the view is used. Here is the blog post on this subject: Interesting Observation – TOP 100 PERCENT and ORDER BY. Now when you create a new view in the SSMS and build a query with ORDER BY to avoid the error automatically it adds the TOP 100 PERCENT. Here is the connect item for the same issue. I am sure there will be more connect items as well but I could not find them. 3) Potential Solutions If you are reading this post from the beginning in that case, it is clear by now that ORDER BY should not be used in the View as it does not serve any purpose unless there is a specific need of it. If you are going to use TOP 100 PERCENT with ORDER BY there is absolutely no need of using ORDER BY rather avoid using it all together. Here is another blog post of mine which describes the same subject ORDER BY Does Not Work – Limitation of the Views Part 1. It is valid to use ORDER BY in a view if there is a clear business need of using TOP with any other percentage lower than 100 (for example TOP 10 PERCENT or TOP 50 PERCENT etc). In most of the cases ORDER BY is not needed in the view and it should be used in the most outer query for present result in desired order. User can remove TOP 100 PERCENT and ORDER BY from the view before using the view in any query or procedure. In the most outer query there should be ORDER BY as per the business need. I think this sums up the concept in a few words. This is a very long topic and not easy to illustrate in one single blog post. I welcome your comments and suggestions. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, SQL View, T SQL, Technology

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