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• Unauthorized Access Exception using Web Deploy to Site when the site root is a UNC path

  - by Peter LaComb Jr.

  I am trying to use Web Deploy to deploy a site where the Site is rooted on a UNC path instead of a local drive. This is because I want to have a shared configuration, and have all servers point to the same UNC for content. That would allow me to deploy to one server and have all servers updated at the same time. I've created a share with everyone and users read/write. The NTFS permissions have the ID of the appDomain account as full control, and that is the same account that is configured as the specific user in Management Service Delegation. I can log on to the destination server as that ID, access the share and create/delete files. However, I'm getting the following exception in my Microsoft Web Deploy log on the destination server: User: Client IP: 192.168.62.174 Content-Type: application/msdeploy Version: 9.0.0.0 MSDeploy.VersionMin: 7.1.600.0 MSDeploy.VersionMax: 9.0.1631.0 MSDeploy.Method: Sync MSDeploy.RequestId: c060c823-cdb4-4abe-8294-5ffbdc327d2e MSDeploy.RequestCulture: en-US MSDeploy.RequestUICulture: en-US ServerVersion: 9.0.1631.0 Skip: objectName="^configProtectedData$" Provider: auto, Path: A tracing deployment agent exception occurred that was propagated to the client. Request ID 'c060c823-cdb4-4abe-8294-5ffbdc327d2e'. Request Timestamp: '8/23/2012 11:01:56 AM'. Error Details: ERROR_INSUFFICIENT_ACCESS_TO_SITE_FOLDER Microsoft.Web.Deployment.DeploymentDetailedUnauthorizedAccessException: Unable to perform the operation ("Create Directory") for the specified directory ("\someserver.mydomain.local\sharename\sitename\applicationName"). This can occur if the server administrator has not authorized this operation for the user credentials you are using. Learn more at: http://go.microsoft.com/fwlink/?LinkId=221672#ERROR_INSUFFICIENT_ACCESS_TO_SITE_FOLDER. --- Microsoft.Web.Deployment.DeploymentException: The error code was 0x80070005. --- System.UnauthorizedAccessException: Access to the path '\someserver.mydomain.local\sharename\sitename\applicationName' is denied. at Microsoft.Web.Deployment.NativeMethods.RaiseIOExceptionFromErrorCode(Win32ErrorCode errorCode, String maybeFullPath) at Microsoft.Web.Deployment.DirectoryEx.CreateDirectory(String path) at Microsoft.Web.Deployment.DirPathProviderBase.CreateDirectory(String fullPath, DeploymentObject source) at Microsoft.Web.Deployment.DirPathProviderBase.Add(DeploymentObject source, Boolean whatIf) --- End of inner exception stack trace --- --- End of inner exception stack trace --- at Microsoft.Web.Deployment.FilePathProviderBase.HandleKnownRetryableExceptions(DeploymentBaseContext baseContext, Int32[] errorsToIgnore, Exception e, String path, String operation) at Microsoft.Web.Deployment.DirPathProviderBase.Add(DeploymentObject source, Boolean whatIf) at Microsoft.Web.Deployment.DeploymentObject.Add(DeploymentObject source, DeploymentSyncContext syncContext) at Microsoft.Web.Deployment.DeploymentSyncContext.HandleAdd(DeploymentObject destObject, DeploymentObject sourceObject) at Microsoft.Web.Deployment.DeploymentSyncContext.HandleUpdate(DeploymentObject destObject, DeploymentObject sourceObject) at Microsoft.Web.Deployment.DeploymentSyncContext.SyncChildrenNoOrder(DeploymentObject dest, DeploymentObject source) at Microsoft.Web.Deployment.DeploymentSyncContext.SyncChildrenNoOrder(DeploymentObject dest, DeploymentObject source) at Microsoft.Web.Deployment.DeploymentSyncContext.SyncChildrenOrder(DeploymentObject dest, DeploymentObject source) at Microsoft.Web.Deployment.DeploymentSyncContext.ProcessSync(DeploymentObject destinationObject, DeploymentObject sourceObject) at Microsoft.Web.Deployment.DeploymentObject.SyncToInternal(DeploymentObject destObject, DeploymentSyncOptions syncOptions, PayloadTable payloadTable, ContentRootTable contentRootTable, Nullable1 syncPassId) at Microsoft.Web.Deployment.DeploymentAgent.HandleSync(DeploymentAgentAsyncData asyncData, Nullable1 passId) at Microsoft.Web.Deployment.DeploymentAgent.HandleRequestWorker(DeploymentAgentAsyncData asyncData) at Microsoft.Web.Deployment.DeploymentAgent.HandleRequest(DeploymentAgentAsyncData asyncData) This is shown as the following on the console of the machine where I run the deployment: C:\Users\PLaComb"C:\Program Files (x86)\IIS\Microsoft Web Deploy V3\msdeploy.exe" -source:package='C:\Packages\Deployments\applicationName.zip' -dest:auto,computerName='https://SERVERNAME:8172/msdeploy.axd',includeAcls='True' -verb:sync -disableLink:AppPoolExtension -disableLink:ContentExtension -disableLink:CertificateExtension -setParamFile:"C:\Packages\Deployments\applicationName.SetParameters.xml" -allowUntrusted Info: Using ID 'c060c823-cdb4-4abe-8294-5ffbdc327d2e' for connections to the remote server. Info: Adding sitemanifest (sitemanifest). Info: Adding virtual path (JMS/admin) Info: Adding directory (JMS/admin). Error Code: ERROR_INSUFFICIENT_ACCESS_TO_SITE_FOLDER More Information: Unable to perform the operation ("Create Directory") for the specified directory ("\someserver.mydomain.local\sharename\sitename\applicationName"). This can occur if the server administrator has not authorized this operation for the user credentials you are using. Learn more at: http://go.microsoft.com/fwlink/?LinkId=221672#ERROR_INSUFFICIENT_ACCESS_TO_SITE_FOLDER. Error: The error code was 0x80070005. Error: Access to the path '\someserver.mydomain.local\sharename\sitename\applicationName' is denied. Error count: 1.

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• how to uninstall mariadb and re-install mysql ? Mysql install turns into mariadb install

  - by Suma

  I recently upgraded my centos system via the desktop. mistake! I had mariadb, phpmyadmin working just fine before - but after the upgrade they stopped. I frantically googled and tried to follow some tutorials about mariadb * mysql reinstall untill I came to this one: http://centosforge.com/node/how-replace-mysql-mariadb-centos-6-including-mysql-uninstall-instructions-and-yum-install I executed this command to remove all of mysql: yum remove mysql-server mysql-libs mysql-devel mysql* and then tried to reinstall mysql: as below - it crashes with errors as follows: ***************************************************************** [root@localhost ~]# yum install mysql-server mysql mysql-devel ***************************************************************** Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: centos.serverspace.co.uk * extras: centos.serverspace.co.uk * rpmforge: www.mirrorservice.org * updates: mirror.rmg.io Setting up Install Process Package mysql-server is obsoleted by MariaDB-server, trying to install MariaDB-server-5.5.29-1.i686 instead Package mysql is obsoleted by MariaDB-server, trying to install MariaDB-server-5.5.29-1.i686 instead Package mysql-devel is obsoleted by MariaDB-devel, trying to install MariaDB-devel-5.5.29-1.i686 instead Resolving Dependencies --> Running transaction check ---> Package MariaDB-devel.i686 0:5.5.29-1 set to be updated --> Processing Dependency: MariaDB-common for package: MariaDB-devel ---> Package MariaDB-server.i686 0:5.5.29-1 set to be updated --> Processing Dependency: libssl.so.10 for package: MariaDB-server --> Processing Dependency: libcrypto.so.10 for package: MariaDB-server --> Running transaction check ---> Package MariaDB-common.i686 0:5.5.29-1 set to be updated --> Processing Dependency: MariaDB-compat for package: MariaDB-common ---> Package MariaDB-server.i686 0:5.5.29-1 set to be updated --> Processing Dependency: libssl.so.10 for package: MariaDB-server --> Processing Dependency: libcrypto.so.10 for package: MariaDB-server --> Running transaction check ---> Package MariaDB-compat.i686 0:5.5.29-1 set to be updated ---> Package MariaDB-server.i686 0:5.5.29-1 set to be updated --> Processing Dependency: libssl.so.10 for package: MariaDB-server --> Processing Dependency: libcrypto.so.10 for package: MariaDB-server --> Finished Dependency Resolution MariaDB-server-5.5.29-1.i686 from mariadb has depsolving problems --> Missing Dependency: libcrypto.so.10 is needed by package MariaDB-server-5.5.29-1.i686 (mariadb) MariaDB-server-5.5.29-1.i686 from mariadb has depsolving problems --> Missing Dependency: libssl.so.10 is needed by package MariaDB-server-5.5.29-1.i686 (mariadb) Error: Missing Dependency: libcrypto.so.10 is needed by package MariaDB-server-5.5.29-1.i686 (mariadb) Error: Missing Dependency: libssl.so.10 is needed by package MariaDB-server-5.5.29-1.i686 (mariadb) You could try using --skip-broken to work around the problem You could try running: package-cleanup --problems package-cleanup --dupes rpm -Va --nofiles --nodigest [root@localhost ~] If I now try to install libssl.10, i get asked to install glibc libraries. 2.17 and 2.7 - other discussions have said to stay clear of the as this will explode my system - I tried download 2.17 and it's huge - took ages to unzip. Could someone please help me to completelty remove maraidb and install mysql - so that I don't get the above errors and pushed over to mariadb when I run: yum install mysql-server mysql mysql-devel There are tons of material on how to install mariadb - but none i found so far that plainly explains how to go backwards to mysql.

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• Long connection times from PHP to MySQL on EC2

  - by Erik Giberti

  I'm having an intermittent issue connecting to a database slave with InnoDB. Intermittently I get connections taking longer than 2 seconds. These servers are hosted on Amazon's EC2. The app server is PHP 5.2/Apache running on Ubuntu. The DB slave is running Percona's XtraDB 5.1 on Ubuntu 9.10. It's using an EBS Raid array for the data storage. We already use skip name resolve and bind to address 0.0.0.0. This is a stub of the PHP code that's failing $tmp = mysqli_init(); $start_time = microtime(true); $tmp-options(MYSQLI_OPT_CONNECT_TIMEOUT, 2); $tmp-real_connect($DB_SERVERS[$server]['server'], $DB_SERVERS[$server]['username'], $DB_SERVERS[$server]['password'], $DB_SERVERS[$server]['schema'], $DB_SERVERS[$server]['port']); if(mysqli_connect_errno()){ $timer = microtime(true) - $start_time; mail($errors_to,'DB connection error',$timer); } There's more than 300Mb available on the DB server for new connections and the server is nowhere near the max allowed (60 of 1,200). Loading on both servers is < 2 on 4 core m1.xlarge instances. Some highlights from the mysql config max_connections = 1200 thread_stack = 512K thread_cache_size = 1024 thread_concurrency = 16 innodb-file-per-table innodb_additional_mem_pool_size = 16M innodb_buffer_pool_size = 13G Any help on tracing the source of the slowdown is appreciated. [EDIT] I have been updating the sysctl values for the network but they don't seem to be fixing the problem. I made the following adjustments on both the database and application servers. net.ipv4.tcp_window_scaling = 1 net.ipv4.tcp_sack = 0 net.ipv4.tcp_timestamps = 0 net.ipv4.tcp_fin_timeout = 20 net.ipv4.tcp_keepalive_time = 180 net.ipv4.tcp_max_syn_backlog = 1280 net.ipv4.tcp_synack_retries = 1 net.core.rmem_max = 16777216 net.core.wmem_max = 16777216 net.ipv4.tcp_rmem = 4096 87380 16777216 net.ipv4.tcp_wmem = 4096 87380 16777216 [EDIT] Per jaimieb's suggestion, I added some tracing and captured the following data using time. This server handles about 51 queries/second at this the time of day. The connection error was raised once (at 13:06:36) during the 3 minute window outlined below. Since there was 1 failure and roughly 9,200 successful connections, I think this isn't going to produce anything meaningful in terms of reporting. Script: date /root/database_server.txt (time mysql -h database_Server -D schema_name -u appuser -p apppassword -e '') /dev/null 2 /root/database_server.txt Results: === Application Server 1 === Mon Feb 22 13:05:01 EST 2010 real 0m0.008s user 0m0.001s sys 0m0.000s Mon Feb 22 13:06:01 EST 2010 real 0m0.007s user 0m0.002s sys 0m0.000s Mon Feb 22 13:07:01 EST 2010 real 0m0.008s user 0m0.000s sys 0m0.001s === Application Server 2 === Mon Feb 22 13:05:01 EST 2010 real 0m0.009s user 0m0.000s sys 0m0.002s Mon Feb 22 13:06:01 EST 2010 real 0m0.009s user 0m0.001s sys 0m0.003s Mon Feb 22 13:07:01 EST 2010 real 0m0.008s user 0m0.000s sys 0m0.001s === Database Server === Mon Feb 22 13:05:01 EST 2010 real 0m0.016s user 0m0.000s sys 0m0.010s Mon Feb 22 13:06:01 EST 2010 real 0m0.006s user 0m0.010s sys 0m0.000s Mon Feb 22 13:07:01 EST 2010 real 0m0.016s user 0m0.000s sys 0m0.010s [EDIT] Per a suggestion received on a LinkedIn question, I tried setting the back_log value higher. We had been running the default value (50) and increased it to 150. We also raised the kernel value /proc/sys/net/core/somaxconn (maximum socket connections) to 256 on both the application and database server from the default 128. We did see some elevation in processor utilization as a result but still received connection timeouts.

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• Error during GENERAL_REQUEST_ENTITY for POST results in ASP .NET session state never getting unlocked

  - by Jesse

  I have been trying to chase down the root cause of a condition where ASP .NET session state remains locked after a web request has been terminated due to an unexpected error. We use the SQL Server session state provider for session because we have several servers in a web farm. This issue first presented itself in the form of many requests getting stuck on the 'AcquireRequestState' event of their lifecycle for no apparent reason. I was able to finding corresponding entries for these requests in the session state database in SQL server that were all locked (column Locked = 1). I was also able to correlate these requests to entries in the IIS log with HTTP status codes of 500 (with a sub status of 0). These findings lead me to believe that, in some cases, a request was erroring out but was NOT releasing its lock on session state like it should. I enabled Failed Request Tracing in IIS for the website in question for status code 500 with all available providers selected each with the 'Verbose' setting for verbosity. I've since gathered several failed traces that have caused permanently locked ASP .NET sessions. They all share the same characteristics: They are all 'POST' requests where the browser is posting data to be processed/saved. They all have events indicating that the 'Session' module was invoked during the REQUEST_ACQUIRE_STATE event. At this point the request would have marked the row in the session state database as being "locked". This is normal and expected. They all have GENERAL_READ_ENTITY_START, GENERAL_READ_ENTITY_END, and GENERAL_REQUEST_ENTITY entries that appear to be reading in the data that was posted to the server as part of the request. This appears to be a buffered operation as these events get repeated over and over with each one reading in some subset of the posted data. At some point during the 'read entity' related events and error occurs. Some have the error code "Incorrect function. (0x80070001)" and others have "The I/O operation has been aborted because of either a thread exit or an application request. (0x800703e3)". Once the error has been encountered, they all jump directly to the END_REQUEST events. The issue here is that, under normal circumstances, there should be a RELEASE_REQUEST_STATE event that will allow the Session module to release the lock it has on the session. This event is being skipped in this scenario. Just to be sure, I enabled failed request tracing for the '200' status code as well and generated several traces of successful requests that do have the RELEASE_REQUEST_STATE event being handled by the Session module. My theory at this point is that some kind of network issue is causing the 'Incorrect function' and 'I/O operation has been aborted because of either a thread exit or an application request' errors, but I don't understand why this seems to be causing the request handling to skip over the RELEASE_REQUEST_STATE event. If the request went through REQUEST_ACQUIRE_STATE it seems like it should also hit RELEASE_REQUEST_STATE as well. I'm loathe to say that this is a bug in IIS or ASP .NET, but it certainly appears that way to me at this point. Are there any configuration changes I could make to help ensure that 'RELEASE_REQUEST_STATE' is fired under all error conditions?

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• Linux software RAID6: rebuild slow

  - by Ole Tange

  I am trying to find the bottleneck in the rebuilding of a software raid6. ## Pause rebuilding when measuring raw I/O performance # echo 1 > /proc/sys/dev/raid/speed_limit_min # echo 1 > /proc/sys/dev/raid/speed_limit_max ## Drop caches so that does not interfere with measuring # sync ; echo 3 | tee /proc/sys/vm/drop_caches >/dev/null # time parallel -j0 "dd if=/dev/{} bs=256k count=4000 | cat >/dev/null" ::: sdbd sdbc sdbf sdbm sdbl sdbk sdbe sdbj sdbh sdbg 4000+0 records in 4000+0 records out 1048576000 bytes (1.0 GB) copied, 7.30336 s, 144 MB/s [... similar for each disk ...] # time parallel -j0 "dd if=/dev/{} skip=15000000 bs=256k count=4000 | cat >/dev/null" ::: sdbd sdbc sdbf sdbm sdbl sdbk sdbe sdbj sdbh sdbg 4000+0 records in 4000+0 records out 1048576000 bytes (1.0 GB) copied, 12.7991 s, 81.9 MB/s [... similar for each disk ...] So we can read sequentially at 140 MB/s in the outer tracks and 82 MB/s in the inner tracks on all the drives simultaneously. Sequential write performance is similar. This would lead me to expect a rebuild speed of 82 MB/s or more. # echo 800000 > /proc/sys/dev/raid/speed_limit_min # echo 800000 > /proc/sys/dev/raid/speed_limit_max # cat /proc/mdstat md2 : active raid6 sdbd[10](S) sdbc[9] sdbf[0] sdbm[8] sdbl[7] sdbk[6] sdbe[11] sdbj[4] sdbi[3](F) sdbh[2] sdbg[1] 27349121408 blocks super 1.2 level 6, 128k chunk, algorithm 2 [9/8] [UUU_UUUUU] [=========>...........] recovery = 47.3% (1849905884/3907017344) finish=855.9min speed=40054K/sec But we only get 40 MB/s. And often this drops to 30 MB/s. # iostat -dkx 1 sdbc 0.00 8023.00 0.00 329.00 0.00 33408.00 203.09 0.70 2.12 1.06 34.80 sdbd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 sdbe 13.00 0.00 8334.00 0.00 33388.00 0.00 8.01 0.65 0.08 0.06 47.20 sdbf 0.00 0.00 8348.00 0.00 33388.00 0.00 8.00 0.58 0.07 0.06 48.00 sdbg 16.00 0.00 8331.00 0.00 33388.00 0.00 8.02 0.71 0.09 0.06 48.80 sdbh 961.00 0.00 8314.00 0.00 37100.00 0.00 8.92 0.93 0.11 0.07 54.80 sdbj 70.00 0.00 8276.00 0.00 33384.00 0.00 8.07 0.78 0.10 0.06 48.40 sdbk 124.00 0.00 8221.00 0.00 33380.00 0.00 8.12 0.88 0.11 0.06 47.20 sdbl 83.00 0.00 8262.00 0.00 33380.00 0.00 8.08 0.96 0.12 0.06 47.60 sdbm 0.00 0.00 8344.00 0.00 33376.00 0.00 8.00 0.56 0.07 0.06 47.60 iostat says the disks are not 100% busy (but only 40-50%). This fits with the hypothesis that the max is around 80 MB/s. Since this is software raid the limiting factor could be CPU. top says: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 38520 root 20 0 0 0 0 R 64 0.0 2947:50 md2_raid6 6117 root 20 0 0 0 0 D 53 0.0 473:25.96 md2_resync So md2_raid6 and md2_resync are clearly busy taking up 64% and 53% of a CPU respectively, but not near 100%. The chunk size (128k) of the RAID was chosen after measuring which chunksize gave the least CPU penalty. If this speed is normal: What is the limiting factor? Can I measure that? If this speed is not normal: How can I find the limiting factor? Can I change that?

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• mysqld service crashes on restart, after importing mysqldump #innodb

  - by ubunut

  I have 2 mysql servers. Let's call them server01 & server02. Both have the same configuration: mysqladmin Ver 8.42 Distrib 5.1.61, for redhat-linux-gnu on x86_64 [client] default-character-set=utf8 [mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock user=mysql # Disabling symbolic-links is recommended to prevent assorted security risks symbolic-links=0 max_allowed_packet = 16M default-character-set=utf8 default-collation=utf8_unicode_ci character-set-server=utf8 collation-server=utf8_unicode_ci default-storage-engine = InnoDB innodb_data_home_dir = /var/lib/mysql innodb_log_group_home_dir = /var/lib/mysql innodb_data_file_path = ibdata1:10M:autoextend innodb_additional_mem_pool_size = 2M innodb_log_file_size = 5M innodb_log_buffer_size = 8M innodb_lock_wait_timeout = 50 innodb_flush_log_at_trx_commit = 1 innodb_buffer_pool_size = 700M table_cache = 300 thread_cache_size = 4 query_cache_size = 200m query_cache_limit = 10m [mysqld_safe] log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid I make a mysqldump on server01: mysqldump -uuser -ppassword --all-databases testservers.sql (most tables in these databases are innodb, some of the mysql.* tables are Innodb too) Then I import the testservers.sql on server02: mysql -uuser < testservers.sql (mysqld has been started with --skip-network). So far so good, I can login into mysql & everything seems to be ok. BUT when I exit to the shell and execute service mysqld restart, The service fails to start. stack-trace in /var/log/mysqld.log: 121022 14:53:19 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql 121022 14:53:19 [Warning] '--default-character-set' is deprecated and will be removed in a future release. Please use '--character-set-server' instead. 121022 14:53:19 [Warning] '--default-collation' is deprecated and will be removed in a future release. Please use '--collation-server' instead. 12:53:19 UTC - mysqld got signal 11 ; This could be because you hit a bug. It is also possible that this binary or one of the libraries it was linked against is corrupt, improperly built, or misconfigured. This error can also be caused by malfunctioning hardware. We will try our best to scrape up some info that will hopefully help diagnose the problem, but since we have already crashed, something is definitely wrong and this may fail. key_buffer_size=8384512 read_buffer_size=131072 max_used_connections=0 max_threads=151 thread_count=0 connection_count=0 It is possible that mysqld could use up to key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 338324 K bytes of memory Hope that's ok; if not, decrease some variables in the equation. Thread pointer: 0x267e630 Attempting backtrace. You can use the following information to find out where mysqld died. If you see no messages after this, something went terribly wrong... stack_bottom = 7fff3efe0be0 thread_stack 0x40000 /usr/libexec/mysqld(my_print_stacktrace+0x29) [0x84bd89] /usr/libexec/mysqld(handle_fatal_signal+0x483) [0x6a0be3] /lib64/libpthread.so.0() [0x338d60f500] /usr/libexec/mysqld(ha_resolve_by_name(THD*, st_mysql_lex_string const*)+0x81) [0x6956e1] /usr/libexec/mysqld(open_table_def(THD*, st_table_share*, unsigned int)+0xe0a) [0x60e5ba] /usr/libexec/mysqld(get_table_share(THD*, TABLE_LIST*, char*, unsigned int, unsigned int, int*)+0x20b) [0x602b0b] /usr/libexec/mysqld() [0x603597] /usr/libexec/mysqld(open_table(THD*, TABLE_LIST*, st_mem_root*, bool*, unsigned int)+0x7a1) [0x6079a1] /usr/libexec/mysqld(open_tables(THD*, TABLE_LIST**, unsigned int*, unsigned int)+0x5d0) [0x608570] /usr/libexec/mysqld(open_and_lock_tables_derived(THD*, TABLE_LIST*, bool)+0x6a) [0x60877a] /usr/libexec/mysqld(plugin_init(int*, char**, int)+0x622) [0x715af2] /usr/libexec/mysqld() [0x5bd3b2] /usr/libexec/mysqld(main+0x1b3) [0x5bfc93] /lib64/libc.so.6(__libc_start_main+0xfd) [0x338d21ecdd] /usr/libexec/mysqld() [0x5087b9] Trying to get some variables. Some pointers may be invalid and cause the dump to abort. Query (0): is an invalid pointer Connection ID (thread ID): 0 Status: NOT_KILLED The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains information that should help you find out what is causing the crash. 121022 14:53:19 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended A typical mysqdump entry looks like this: DROP TABLE IF EXISTS `adodb_logsql`; /*!40101 SET @saved_cs_client = @@character_set_client */; /*!40101 SET character_set_client = utf8 */; CREATE TABLE `adodb_logsql` ( `id` bigint(10) unsigned NOT NULL AUTO_INCREMENT, `created` datetime NOT NULL, `sql0` varchar(250) NOT NULL DEFAULT '', `sql1` text, `params` text, `tracer` text, `timer` decimal(16,6) NOT NULL DEFAULT '0.000000', PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='to save some logs from ADOdb'; /*!40101 SET character_set_client = @saved_cs_client */; IF I change all occurrences of "ENGINE=InnoDB" to "ENGINE=MyISAM" before import, then the service has no problem restarting. I'm quite puzzled as to what's happening, maybe I'm just an idiot, then by all means tell me so. Any help would be greatly appreciated!

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• What's going on with my server? High load, lots of idle CPU time, low disk utilization

  - by Jonathan

  I run a web site and send a legitimate opt-in, daily email newsletter to subscribers. Both the web hosting and email sending are done by the same machine. I have about 100,000 subscribers who have opted in to my daily email newsletter. My PHP script did a pretty good job sending mail to all of them until fairly recently, but as the list has grown I can't keep up. When I run top, I have very high load--usually at least 6 or 7, sometimes as high as 15--even though I only have two CPUs. However, when I run sar, my CPU is idle an average of about 30% of the time. So, it seems I'm not CPU bound. When I run iostat, it seems as though I'm not disk bound because my %util for each device is very low (no more than 5%). Given that I don't seem to be CPU bound or disk bound, why is top reporting such high load? Additionally, since I don't seem to be CPU bound or disk bound, why is my email sending script not able to keep up? Here's what I see when running top: top - 11:33:28 up 74 days, 18:49, 2 users, load average: 7.65, 8.79, 8.28 Tasks: 168 total, 5 running, 162 sleeping, 0 stopped, 1 zombie Cpu(s): 38.9%us, 58.6%sy, 0.8%ni, 0.0%id, 0.7%wa, 0.2%hi, 0.8%si, 0.0%st Mem: 3083012k total, 2144436k used, 938576k free, 281136k buffers Swap: 2048248k total, 39164k used, 2009084k free, 1470412k cached Here's what I see when running iostat -mx: avg-cpu: %user %nice %system %iowait %steal %idle 34.80 1.20 55.24 0.37 0.00 8.38 Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s avgrq-sz avgqu-sz await svctm %util sda 0.19 71.70 1.59 29.45 0.02 0.07 5.90 0.55 17.82 1.16 3.59 sda1 0.00 0.00 0.00 0.00 0.00 0.00 7.10 0.00 13.80 13.72 0.00 sda2 0.05 50.45 1.13 24.57 0.01 0.29 24.25 0.35 13.43 1.15 2.97 sda3 0.05 10.17 0.20 2.33 0.01 0.05 43.75 0.05 20.96 2.45 0.62 sda4 0.00 0.00 0.00 0.00 0.00 0.00 2.00 0.00 70.50 70.50 0.00 sda5 0.07 0.22 0.03 0.07 0.00 0.00 32.84 0.08 856.19 8.03 0.08 sda6 0.02 5.45 0.03 0.72 0.00 0.02 67.55 0.02 26.72 5.26 0.39 sda7 0.00 1.56 0.00 0.42 0.00 0.01 38.04 0.00 8.88 5.84 0.24 sda8 0.01 3.84 0.20 1.35 0.00 0.02 28.55 0.05 31.90 4.08 0.63 Here's what I see when running sar: 09:40:02 AM CPU %user %nice %system %iowait %steal %idle 09:50:01 AM all 30.59 1.01 49.80 0.23 0.00 18.37 10:00:08 AM all 31.73 0.92 51.66 0.13 0.00 15.55 10:10:06 AM all 30.43 0.99 48.94 0.26 0.00 19.38 10:20:01 AM all 29.58 1.00 47.76 0.25 0.00 21.42 10:30:01 AM all 29.37 1.02 47.30 0.18 0.00 22.13 10:40:06 AM all 32.50 1.01 52.94 0.16 0.00 13.39 10:50:01 AM all 30.49 1.00 49.59 0.15 0.00 18.77 11:00:01 AM all 29.43 0.99 47.71 0.17 0.00 21.71 11:10:07 AM all 30.26 0.93 49.48 0.83 0.00 18.50 11:20:02 AM all 29.83 0.81 48.51 1.32 0.00 19.52 11:30:06 AM all 31.18 0.88 51.33 1.15 0.00 15.47 Average: all 26.21 1.15 42.62 0.48 0.00 29.54 Here are the top handful of processes listed at the particular time I happened to run top -c: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 8180 mysql 16 0 57448 19m 2948 S 26.6 0.7 4702:26 /usr/sbin/mysqld --basedir=/ --datadir=/var/lib/mysql --user=mysql --pid-file=/var/lib/mysql/bristno.pid --skip-external-locking 26956 brristno 17 0 0 0 0 Z 8.0 0.0 0:00.24 [php] <defunct> 26958 brristno 17 0 94408 43m 37m R 5.0 1.4 0:00.15 /usr/bin/php /home/brristno/public_html/dbv.php 22852 nobody 16 0 9628 2900 1524 S 0.7 0.1 0:00.17 /usr/local/apache/bin/httpd -k start -DSSL 8591 brristno 34 19 96896 13m 6652 S 0.3 0.4 0:29.82 /usr/local/bin/php /home/brristno/bin/mailer.php 1qwqyb6 i0gbor 24469 nobody 16 0 9628 2880 1508 S 0.3 0.1 0:00.08 /usr/local/apache/bin/httpd -k start -DSSL 25495 nobody 15 0 9628 2876 1500 S 0.3 0.1 0:00.06 /usr/local/apache/bin/httpd -k start -DSSL 26149 nobody 15 0 9628 2864 1504 S 0.3 0.1 0:00.04 /usr/local/apache/bin/httpd -k start -DSSL

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• Setting environment variables in OS X

  - by Percival Ulysses

  Despite the warning that questions that can be answered are preferred, this question is more a request for comments. I apologize for this, but I feel that it is valuable nonetheless. The problem to set up environment variables such that they are available for GUI applications has been around since the dawn of Mac OS X. The solution with ~/.MacOSX/environment.plist never satisfied me because it was not reliable, and bash style globbing wasn't available. Another solution is the use of Login Hooks with a suitable shell script, but these are deprecated. The Apple approved way for such functionality as provided by login hooks is the use of Launch Agents. I provided a launch agent that is located in /Library/LaunchAgents/: <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict> <key>Label</key> <string>user.conf.launchd</string> <key>Program</key> <string>/Users/Shared/conflaunchd.sh</string> <key>ProgramArguments</key> <array> <string>~/.conf.launchd</string> </array> <key>EnableGlobbing</key> <true/> <key>RunAtLoad</key> <true/> <key>LimitLoadToSessionType</key> <array> <string>Aqua</string> <string>StandardIO</string> </array> </dict> </plist> The real work is done in the shell script /Users/Shared/conflaunchd.sh, which reads ~/.conf.launchd and feeds it to launchctl: #! /bin/bash #filename="$1" filename="$HOME/.conf.launchd" if [ ! -r "$filename" ]; then exit fi eval $(/usr/libexec/path_helper -s) while read line; do # skip lines that only contain whitespace or a comment if [ ! -n "$line" -o `expr "$line" : '#'` -gt 0 ]; then continue; fi eval launchctl $line done <"$filename" exit 0 Notice the call of path_helper to get PATH set up right. Finally, ~/.conf.launchd looks like that setenv PATH ~/Applications:"${PATH}" setenv TEXINPUTS .:~/Documents/texmf//: setenv BIBINPUTS .:~/Documents/texmf/bibtex//: setenv BSTINPUTS .:~/Documents/texmf/bibtex//: # Locale setenv LANG en_US.UTF-8 These are launchctl commands, see its manpage for further information. Works fine for me (I should mention that I'm still a Snow Leopard guy), GUI applications such as texstudio can see my local texmf tree. Things that can be improved: The shell script has a #filename="$1" in it. This is not accidental, as the file name should be feeded to the script by the launch agent as an argument, but that doesn't work. It is possible to put the script in the launch agent itsself. I am not sure how secure this solution is, as it uses eval with user provided strings. It should be mentioned that Apple intended a somewhat similar approach by putting stuff in ~/launchd.conf, but it is currently unsupported as to this date and OS (see the manpage of launchd.conf). I guess that things like globbing would not work as they do in this proposal. Finally, I would mention the sources I used as information on Launch Agents, but StackExchange doesn't let me [1], [2], [3]. Again, I am sorry that this is not a real question, I still hope it is useful.

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• AMD Catalyst 13.9 installation failure

  - by Simon Verbeke

  Earlier today I installed Windows 8.1, and when I wanted to go into Catalyst Control Center, I noticed some odd error of CCC not being able to display options. I then figured I needed a driver update, so I downloaded the latest drivers, version 13.9, and tried to install them. While it was trying to install the display drivers, I got a blue screen. Tried again and got the same. Then I used an uninstall tool from AMD to remove all traces of my old drivers and tried to install the new drivers. Again, a blue screen. This is all I could think of to try. Would anyone know some other things I can try? EDIT: thought I might want to include the log entry for the crash: - <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event"> - <System> <Provider Name="Microsoft-Windows-WER-SystemErrorReporting" Guid="{ABCE23E7-DE45-4366-8631-84FA6C525952}" EventSourceName="BugCheck" /> <EventID Qualifiers="16384">1001</EventID> <Version>0</Version> <Level>2</Level> <Task>0</Task> <Opcode>0</Opcode> <Keywords>0x80000000000000</Keywords> <TimeCreated SystemTime="2013-10-19T20:59:25.000000000Z" /> <EventRecordID>26587</EventRecordID> <Correlation /> <Execution ProcessID="0" ThreadID="0" /> <Channel>System</Channel> <Computer>Simon-PC</Computer> <Security /> </System> - <EventData> <Data Name="param1">0x0000007e (0xffffffffc0000005, 0xfffff80002a86dca, 0xffffd00025f250e8, 0xffffd00025f248f0)</Data> <Data Name="param2">C:\WINDOWS\MEMORY.DMP</Data> <Data Name="param3">101913-8953-01</Data> </EventData> </Event> Another edit: As it turns out, the graphics card isn't showing up any more in the device manager. But as far as I can tell, it is still working (the fans are spinning and my screen is plugged into that graphics card). This is solved. it appears that my graphics card is now running with a default windows driver. I also tried the forced method mentioned here: AMD Graphics Drivers won't install properly . But I still get a BSOD. Third edit: Slight succes! Managed to install version 13.4. Everything appears to be working fine now. I think I'm just going to skip version 13.9.

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• How do I allow mysqld to use more than 24.9% of my cpu?

  - by Joseph Yancey

  I have a Web server running on RHEL that is running Apache and MySQL. It has a Quad core 3.2Ghz Xeon CPU and 8 Gigs of RAM Most of the time, we don't have any issues at all. Our web application is very database intensive. When our usage gets pretty heavy MySQL will peg out at using 24.9% of the cpu. Most of the time, it hangs around below 5%. I have speculated that it is only using one core of the CPU and it is pegging out that core but TOP shows me in the cpu column that mysqld changes cores even while the usage stays at 24.9%. When it does this MySQL gets painfully slow as it is queuing up queries Is there some magic configuration that will tell mysql to use more cpu when it needs to? Also, any other advice on my configuration would be helpful. We run two applications on this server. One that runs Innodb but doesn't get much usage (it has been replaced by the other app), and one that runs MyIsam and gets lots of use. Overall, our whole mysql data directory is something like 13Gigs if that matters at all. Here is my config: [root@ProductionLinux root]# cat /etc/my.cnf [mysqld] server-id = 71 log-bin = /var/log/mysql/mysql-bin.log binlog-do-db = oldapplication binlog-do-db = newapplication binlog-do-db = support thread_cache_size = 30 key_buffer_size = 256M table_cache = 256 sort_buffer_size = 4M read_buffer_size = 1M skip-name-resolve innodb_data_home_dir = /usr/local/mysql/data/ innodb_data_file_path = InnoDB:100M:autoextend set-variable = innodb_buffer_pool_size=70M set-variable = innodb_additional_mem_pool_size=10M set-variable = max_connections=500 innodb_log_group_home_dir = /usr/local/mysql/data innodb_log_arch_dir = /usr/local/mysql/data set-variable = innodb_log_file_size=20M set-variable = innodb_log_buffer_size=8M innodb_flush_log_at_trx_commit = 1 log-queries-not-using-indexes log-error = /var/log/mysql/mysql-error.log mysql show variables; +---------------------------------+-----------------------------------------------------------------------------+ | Variable_name | Value | +---------------------------------+-----------------------------------------------------------------------------+ | auto_increment_increment | 1 | | auto_increment_offset | 1 | | automatic_sp_privileges | ON | | back_log | 50 | | basedir | /usr/local/mysql-standard-5.0.18-linux-x86_64-glibc23/ | | binlog_cache_size | 32768 | | bulk_insert_buffer_size | 8388608 | | character_set_client | latin1 | | character_set_connection | latin1 | | character_set_database | latin1 | | character_set_results | latin1 | | character_set_server | latin1 | | character_set_system | utf8 | | character_sets_dir | /usr/local/mysql-standard-5.0.18-linux-x86_64-glibc23/share/mysql/charsets/ | | collation_connection | latin1_swedish_ci | | collation_database | latin1_swedish_ci | | collation_server | latin1_swedish_ci | | completion_type | 0 | | concurrent_insert | 1 | | connect_timeout | 5 | | datadir | /usr/local/mysql/data/ | | date_format | %Y-%m-%d | | datetime_format | %Y-%m-%d %H:%i:%s | | default_week_format | 0 | | delay_key_write | ON | | delayed_insert_limit | 100 | | delayed_insert_timeout | 300 | | delayed_queue_size | 1000 | | div_precision_increment | 4 | | engine_condition_pushdown | OFF | | expire_logs_days | 0 | | flush | OFF | | flush_time | 0 | | | ft_max_word_len | 84 | | ft_min_word_len | 4 | | ft_query_expansion_limit | 20 | | ft_stopword_file | (built-in) | | group_concat_max_len | 1024 | | have_archive | YES | | have_bdb | NO | | have_blackhole_engine | NO | | have_compress | YES | | have_crypt | YES | | have_csv | NO | | have_example_engine | NO | | have_federated_engine | NO | | have_geometry | YES | | have_innodb | YES | | have_isam | NO | | have_ndbcluster | NO | | have_openssl | NO | | have_query_cache | YES | | have_raid | NO | | have_rtree_keys | YES | | have_symlink | YES | | init_connect | | | init_file | | | init_slave | | | innodb_additional_mem_pool_size | 10485760 | | innodb_autoextend_increment | 8 | | innodb_buffer_pool_awe_mem_mb | 0 | | innodb_buffer_pool_size | 73400320 | | innodb_checksums | ON | | innodb_commit_concurrency | 0 | | innodb_concurrency_tickets | 500 | | innodb_data_file_path | InnoDB:100M:autoextend | | innodb_data_home_dir | /usr/local/mysql/data/ | | innodb_doublewrite | ON | | innodb_fast_shutdown | 1 | | innodb_file_io_threads | 4 | | innodb_file_per_table | OFF | | innodb_flush_log_at_trx_commit | 1 | | innodb_flush_method | | | innodb_force_recovery | 0 | | innodb_lock_wait_timeout | 50 | | innodb_locks_unsafe_for_binlog | OFF | | innodb_log_arch_dir | /usr/local/mysql/data | | innodb_log_archive | OFF | | innodb_log_buffer_size | 8388608 | | innodb_log_file_size | 20971520 | | innodb_log_files_in_group | 2 | | innodb_log_group_home_dir | /usr/local/mysql/data | | innodb_max_dirty_pages_pct | 90 | | innodb_max_purge_lag | 0 | | innodb_mirrored_log_groups | 1 | | innodb_open_files | 300 | | innodb_support_xa | ON | | innodb_sync_spin_loops | 20 | | innodb_table_locks | ON | | innodb_thread_concurrency | 20 | | innodb_thread_sleep_delay | 10000 | | interactive_timeout | 28800 | | join_buffer_size | 131072 | | key_buffer_size | 268435456 | | key_cache_age_threshold | 300 | | key_cache_block_size | 1024 | | key_cache_division_limit | 100 | | language | /usr/local/mysql-standard-5.0.18-linux-x86_64-glibc23/share/mysql/english/ | | large_files_support | ON | | large_page_size | 0 | | large_pages | OFF | | license | GPL | | local_infile | ON | | locked_in_memory | OFF | | log | OFF | | log_bin | ON | | log_bin_trust_function_creators | OFF | | log_error | /var/log/mysql/mysql-error.log | | log_slave_updates | OFF | | log_slow_queries | OFF | | log_warnings | 1 | | long_query_time | 10 | | low_priority_updates | OFF | | lower_case_file_system | OFF | | lower_case_table_names | 0 | | max_allowed_packet | 1048576 | | max_binlog_cache_size | 18446744073709551615 | | max_binlog_size | 1073741824 | | max_connect_errors | 10 | | max_connections | 500 | | max_delayed_threads | 20 | | max_error_count | 64 | | max_heap_table_size | 16777216 | | max_insert_delayed_threads | 20 | | max_join_size | 18446744073709551615 | | max_length_for_sort_data | 1024 | | max_relay_log_size | 0 | | max_seeks_for_key | 18446744073709551615 | | max_sort_length | 1024 | | max_sp_recursion_depth | 0 | | max_tmp_tables | 32 | | max_user_connections | 0 | | max_write_lock_count | 18446744073709551615 | | multi_range_count | 256 | | myisam_data_pointer_size | 6 | | myisam_max_sort_file_size | 9223372036854775807 | | myisam_recover_options | OFF | | myisam_repair_threads | 1 | | myisam_sort_buffer_size | 8388608 | | myisam_stats_method | nulls_unequal | | net_buffer_length | 16384 | | net_read_timeout | 30 | | net_retry_count | 10 | | net_write_timeout | 60 | | new | OFF | | old_passwords | OFF | | open_files_limit | 2510 | | optimizer_prune_level | 1 | | optimizer_search_depth | 62 | | pid_file | /usr/local/mysql/data/ProductionLinux.pid | | port | 3306 | | preload_buffer_size | 32768 | | protocol_version | 10 | | query_alloc_block_size | 8192 | | query_cache_limit | 1048576 | | query_cache_min_res_unit | 4096 | | query_cache_size | 0 | | query_cache_type | ON | | query_cache_wlock_invalidate | OFF | | query_prealloc_size | 8192 | | range_alloc_block_size | 2048 | | read_buffer_size | 1044480 | | read_only | OFF | | read_rnd_buffer_size | 262144 | | relay_log_purge | ON | | relay_log_space_limit | 0 | | rpl_recovery_rank | 0 | | secure_auth | OFF | | server_id | 71 | | skip_external_locking | ON | | skip_networking | OFF | | skip_show_database | OFF | | slave_compressed_protocol | OFF | | slave_load_tmpdir | /tmp/ | | slave_net_timeout | 3600 | | slave_skip_errors | OFF | | slave_transaction_retries | 10 | | slow_launch_time | 2 | | socket | /tmp/mysql.sock | | sort_buffer_size | 4194296 | | sql_mode | | | sql_notes | ON | | sql_warnings | ON | | storage_engine | MyISAM | | sync_binlog | 0 | | sync_frm | ON | | sync_replication | 0 | | sync_replication_slave_id | 0 | | sync_replication_timeout | 10 | | system_time_zone | CST | | table_cache | 256 | | table_lock_wait_timeout | 50 | | table_type | MyISAM | | thread_cache_size | 30 | | thread_stack | 262144 | | time_format | %H:%i:%s | | time_zone | SYSTEM | | timed_mutexes | OFF | | tmp_table_size | 33554432 | | tmpdir | | | transaction_alloc_block_size | 8192 | | transaction_prealloc_size | 4096 | | tx_isolation | REPEATABLE-READ | | updatable_views_with_limit | YES | | version | 5.0.18-standard-log | | version_comment | MySQL Community Edition - Standard (GPL) | | version_compile_machine | x86_64 | | version_compile_os | unknown-linux-gnu | | wait_timeout | 28800 | +---------------------------------+-----------------------------------------------------------------------------+ 210 rows in set (0.00 sec)

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• need assistance with my.cnf - 1500% CPU usage

  - by Alan Long

  I'm running into a few issues with our new database server. It is a HP G8 with 2 INTEL XEON E5-2650 processors and 32GB of ram. This server is dedicated as a MySQL server (5.1.69) for our intranet portal. I have been having issues with this server staying alive - I notice high CPU usage during certain times of day (8% ~ 1500%+) and see very low memory usage (7 ~ 15%) based on using the 'top' command. When the CPU usage passes 1000%, that is when the app usually dies. I'm trying to see what I'm doing wrong with the config file, hopefully one of the experts can chime in and let me know what they think. See below for my.cnf file: [mysqld] default-storage-engine=InnoDB datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock #user=mysql large-pages # Disabling symbolic-links is recommended to prevent assorted security risks symbolic-links=0 max_connections=275 tmp_table_size=1G key_buffer_size=384M key_buffer=384M thread_cache_size=1024 long_query_time=5 low_priority_updates=1 max_heap_table_size=1G myisam_sort_buffer_size=8M concurrent_insert=2 table_cache=1024 sort_buffer_size=8M read_buffer_size=5M read_rnd_buffer_size=6M join_buffer_size=16M table_definition_cache=6k open_files_limit=8k slow_query_log #skip-name-resolve # Innodb Settings innodb_buffer_pool_size=18G innodb_thread_concurrency=0 innodb_log_file_size=1G innodb_log_buffer_size=16M innodb_flush_log_at_trx_commit=2 innodb_lock_wait_timeout=50 innodb_file_per_table #innodb_buffer_pool_instances=4 #eliminating double buffering innodb_flush_method = O_DIRECT flush_time=86400 innodb_additional_mem_pool_size=40M #innodb_io_capacity = 5000 #innodb_read_io_threads = 64 #innodb_write_io_threads = 64 # increase until threads_created doesnt grow anymore thread_cache=1024 query_cache_type=1 query_cache_limit=4M query_cache_size=256M # Try number of CPU's*2 for thread_concurrency thread_concurrency = 0 wait_timeout = 1800 connect_timeout = 10 interactive_timeout = 60 [mysqldump] max_allowed_packet=32M [mysqld_safe] log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid log-slow-queries=/var/log/mysql/slow-queries.log long_query_time = 1 log-queries-not-using-indexes we connect to one database with 75 tables, the largest table has 1,150,000 entries and the second largest has 128,036 entries. I have also verified that our PHP queries are optimized as best as possible. Reference - MySQLtuner: >> MySQLTuner 1.2.0 - Major Hayden <[email protected]> >> Bug reports, feature requests, and downloads at http://mysqltuner.com/ >> Run with '--help' for additional options and output filtering -------- General Statistics -------------------------------------------------- [--] Skipped version check for MySQLTuner script [OK] Currently running supported MySQL version 5.1.69-log [OK] Operating on 64-bit architecture -------- Storage Engine Statistics ------------------------------------------- [--] Status: -Archive -BDB -Federated +InnoDB -ISAM -NDBCluster [--] Data in InnoDB tables: 420M (Tables: 75) [!!] Total fragmented tables: 75 -------- Security Recommendations ------------------------------------------- [!!] User '[email protected]' has no password set. -------- Performance Metrics ------------------------------------------------- [--] Up for: 1h 14m 50s (8M q [1K qps], 705 conn, TX: 6B, RX: 892M) [--] Reads / Writes: 68% / 32% [--] Total buffers: 19.7G global + 35.2M per thread (275 max threads) [!!] Maximum possible memory usage: 29.1G (93% of installed RAM) [OK] Slow queries: 0% (472/8M) [OK] Highest usage of available connections: 66% (183/275) [OK] Key buffer size / total MyISAM indexes: 384.0M/91.0K [OK] Key buffer hit rate: 100.0% (173 cached / 0 reads) [OK] Query cache efficiency: 96.2% (7M cached / 7M selects) [!!] Query cache prunes per day: 553614 [OK] Sorts requiring temporary tables: 0% (3 temp sorts / 1K sorts) [!!] Temporary tables created on disk: 49% (3K on disk / 7K total) [OK] Thread cache hit rate: 74% (183 created / 705 connections) [OK] Table cache hit rate: 97% (231 open / 238 opened) [OK] Open file limit used: 0% (17/8K) [OK] Table locks acquired immediately: 100% (432K immediate / 432K locks) [OK] InnoDB data size / buffer pool: 420.9M/18.0G -------- Recommendations ----------------------------------------------------- General recommendations: Run OPTIMIZE TABLE to defragment tables for better performance MySQL started within last 24 hours - recommendations may be inaccurate Reduce your overall MySQL memory footprint for system stability Increasing the query_cache size over 128M may reduce performance Temporary table size is already large - reduce result set size Reduce your SELECT DISTINCT queries without LIMIT clauses Variables to adjust: *** MySQL's maximum memory usage is dangerously high *** *** Add RAM before increasing MySQL buffer variables *** query_cache_size (> 256M) [see warning above] Thanks in advanced for your help!

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• Create a Bootable Ubuntu 9.10 USB Flash Drive

  - by Trevor Bekolay

  The Ubuntu Live CD isn’t just useful for trying out Ubuntu before you install it, you can also use it to maintain and repair your Windows PC. Even if you have no intention of installing Linux, every Windows user should have a bootable Ubuntu USB drive on hand in case something goes wrong in Windows. Creating a bootable USB flash drive is surprisingly easy with a small self-contained application called UNetbootin. It will even download Ubuntu for you! Note: Ubuntu will take up approximately 700 MB on your flash drive, so choose a flash drive with at least 1 GB of free space, formatted as FAT32. This process should not remove any existing files on the flash drive, but to be safe you should backup the files on your flash drive. Put Ubuntu on your flash drive UNetbootin doesn’t require installation; just download the application and run it. Select Ubuntu from the Distribution drop-down box, then 9.10_Live from the Version drop-down box. If you have a 64-bit machine, then select 9.10_Live_x64 for the Version. At the bottom of the screen, select the drive letter that corresponds to the USB drive that you want to put Ubuntu on. If you select USB Drive in the Type drop-down box, the only drive letters available will be USB flash drives. Click OK and UNetbootin will start doing its thing. First it will download the Ubuntu Live CD. Then, it will copy the files from the Ubuntu Live CD to your flash drive. The amount of time it takes will vary depending on your Internet speed, an when it’s done, click on Exit. You’re not planning on installing Ubuntu right now, so there’s no need to reboot. If you look at the USB drive now, you should see a bunch of new files and folders. If you had files on the drive before, they should still be present. You’re now ready to boot your computer into Ubuntu 9.10! How to boot into Ubuntu When the time comes that you have to boot into Ubuntu, or if you just want to test and make sure that your flash drive works properly, you will have to set your computer to boot off of the flash drive. The steps to do this will vary depending on your BIOS – which varies depending on your motherboard. To get detailed instructions on changing how your computer boots, search for your motherboard’s manual (or your laptop’s manual for a laptop). For general instructions, which will suffice for 99% of you, read on. Find the important keyboard keys When your computer boots up, a bunch of words and numbers flash across the screen, usually to be ignored. This time, you need to scan the boot-up screen for a few key words with some associated keys: Boot menu and Setup. Typically, these will show up at the bottom of the screen. If your BIOS has a Boot Menu, then read on. Otherwise, skip to the Hard: Using Setup section. Easy: Using the Boot Menu If your BIOS offers a Boot Menu, then during the boot-up process, press the button associated with the Boot Menu. In our case, this is ESC. Our example Boot Menu doesn’t have the ability to boot from USB, but your Boot Menu should have some options, such as USB-CDROM, USB-HDD, USB-FLOPPY, and others. Try the options that start with USB until you find one that works. Don’t worry if it doesn’t work – you can just restart and try again. Using the Boot Menu does not change the normal boot order on your system, so the next time you start up your computer it will boot from the hard drive as normal. Hard: Using Setup If your BIOS doesn’t offer a Boot Menu, then you will have to change the boot order in Setup. Note: There are some options in BIOS Setup that can affect the stability of your machine. Take care to only change the boot order options. Press the button associated with Setup. In our case, this is F2. If your BIOS Setup has a Boot tab, then switch to it and change the order such that one of the USB options occurs first. There may be several USB options, such as USB-CDROM, USB-HDD, USB-FLOPPY, and others; try them out to see which one works for you. If your BIOS does not have a boot tab, boot order is commonly found in Advanced CMOS Options. Note that this changes the boot order permanently until you change it back. If you plan on only plugging in a bootable flash drive when you want to boot from it, then you could leave the boot order as it is, but you may find it easier to switch the order back to the previous order when you reboot from Ubuntu. Booting into Ubuntu If you set the right boot option, then you should be greeted with the UNetbootin screen. Press enter to start Ubuntu with the default options, or wait 10 seconds for this to happen automatically. Ubuntu will start loading. It should go straight to the desktop with no need for a username or password. And that’s it! From this live desktop session, you can try out Ubuntu, and even install software that is not included in the live CD. Installed software will only last for the duration of your session – the next time you start up the live CD it will be back to its original state. Download UNetbootin from sourceforge.net Similar Articles Productive Geek Tips Create a Bootable Ubuntu USB Flash Drive the Easy WayReset Your Ubuntu Password Easily from the Live CDHow-To Geek on Lifehacker: Control Your Computer with Shortcuts & Speed Up Vista SetupHow To Setup a USB Flash Drive to Install Windows 7Speed up Your Windows Vista Computer with ReadyBoost TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 PCmover Professional New Stinger from McAfee Helps Remove ‘FakeAlert’ Threats Google Apps Marketplace: Tools & Services For Google Apps Users Get News Quick and Precise With Newser Scan for Viruses in Ubuntu using ClamAV Replace Your Windows Task Manager With System Explorer Create Talking Photos using Fotobabble

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• Why can't I reinstall MySQL?

  - by Johannes Nielsen

  I've been looking all around the Internet for an answer but didn't find anything. I hope you can help me now. I have a server with MySQL. From one day to another, MySQL didn't let me enter with my root password anymore (accsess denied for user 'root'@'localhost' using password: 'YES'). So I tried two ways to reset the password: No.1: I typed: shell> /etc/init.d/mysqld stop To stop MySQL. Then I restarted it skipping the grant-tables: shell> mysqld_safe --skip-grant-tables So I was able to log in as root and change the password using: mysql> UPDATE mysql.user SET Password = PASSWORD('MyNewPassword') WHERE User = 'root'; FLUSH PRIVILEGES; I restarted MySQL and tried to log in as root with my new password - didn't work. So I tried the solution that's described here: http://dev.mysql.com/doc/refman/5.0/en/resetting-permissions.html (I don't want to post it here because this post is already pretty long). Didn't work either. Actually it made it worse, because since that day, every time I try to start MySQL, it doesn't even ask me for my password, but I get: shell> ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (111) Well, I've looked up what it means and found that my mysqld.sock is missing. I tried to create it using touch but MySQL can't start with that socket. Now I'm trying to reinstall MySQL but everytime I type in shell> apt-get --purge remove mysql-server mysql-common mysql-client In that or any other order or every one of those three alone, I get: shell> Reading package lists... Done shell> Building dependency tree shell> Reading state information... Done shell> Package mysql-client is not installed, so not removed shell> Package mysql-server is not installed, so not removed shell> You might want to run 'apt-get -f install' to correct these: shell> The following packages have unmet dependencies: shell> libmysqlclient18 : Depends: mysql-common (>= 5.5.28-0ubuntu0.12.04.2) but it is not going to be installed shell> libmysqlclient18:i386 : Depends: mysql-common:i386 (>= 5.5.28-0ubuntu0.12.04.2) shell> mysql-client-5.5 : Depends: mysql-common (>= 5.5.28-0ubuntu0.12.04.2) but it is not going to be installed shell> mysql-server-5.5 : PreDepends: mysql-common (>= 5.5.28-0ubuntu0.12.04.2) but it is not going to be installed shell> psa-firewall : Depends: plesk-core (>= 11.0.9) but it is not installable shell> Depends: mysql-server but it is not going to be installed shell> psa-spamassassin : Depends: plesk-core (>= 11.0.9) but it is not installable shell> psa-vpn : Depends: plesk-core (>= 11.0.9) but it is not installable shell> Depends: plesk-base (>= 11.0.9) but it is not installable shell> Depends: mysql-server but it is not going to be installed shell> E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution). So I said to my self "let's just remove those files with depenencies, too" (that psa-stuff since plesk is virtual and can't be uninstalled)... Guess what happened: shell> Reading package lists... Done shell> Building dependency tree shell> Reading state information... Done shell> Package mysql-client is not installed, so not removed shell> Package mysql-server is not installed, so not removed shell> You might want to run 'apt-get -f install' to correct these: shell> The following packages have unmet dependencies: shell> libmysqlclient18 : Depends: mysql-common (>= 5.5.28-0ubuntu0.12.04.2) but it is not going to be installed shell> libmysqlclient18:i386 : Depends: mysql-common:i386 (>= 5.5.28-0ubuntu0.12.04.2) shell> mysql-client-5.5 : Depends: mysql-common (>= 5.5.28-0ubuntu0.12.04.2) but it is not going to be installed shell> mysql-server-5.5 : PreDepends: mysql-common (>= 5.5.28-0ubuntu0.12.04.2) but it is not going to be installed shell> E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution). Of course I tried apt-get -f install, too many times even. What am I doing wrong? No matter, which other packages I include into apt-get --purge remove, I always get new dependencies. Do I have to delete every MySQL-related directory and file manually? Hope there's someone out there who can help me! Cheers! EDIT: After trying apt-get purge mysql-server mysql-common mysql-client libmysqlclient18 libmysqlclient18:i386 mysql-client-5.5 mysql-server-5.5 psa-firewall psa-spamassassin psa-vpn Reading package lists... Done Building dependency tree Reading state information... Done Package mysql-client is not installed, so not removed Package mysql-server is not installed, so not removed You might want to run 'apt-get -f install' to correct these: The following packages have unmet dependencies: libdbd-mysql-perl : Depends: libmysqlclient18 (>= 5.5.13-1) but it is not going to be installed libmyodbc : Depends: libmysqlclient18 (>= 5.5.13-1) but it is not going to be installed libqt4-sql-mysql:i386 : Depends: libmysqlclient18:i386 (>= 5.5.13-1) but it is not going to be installed php5-mysql : Depends: libmysqlclient18 (>= 5.5.13-1) but it is not going to be installed ruby-mysql : Depends: libmysqlclient18 (>= 5.5.13-1) but it is not going to be installed E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution). So I tried to remove all these and got: Building dependency tree Reading state information... Done Package mysql-client is not installed, so not removed Package mysql-server is not installed, so not removed You might want to run 'apt-get -f install' to correct these:qlclient18:i386 mysql The following packages have unmet dependencies: libmysql-ruby1.8 : Depends: ruby-mysql but it is not going to be installed E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution). And actually I think removing that file, too solved my problem :-S Next time I'll try everything before asking :D Thank you Eric for keeping me couraged to just go on removing :D

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• Pre-filtering and shaping OData feeds using WCF Data Services and the Entity Framework - Part 1

  - by rajbk

  The Open Data Protocol, referred to as OData, is a new data-sharing standard that breaks down silos and fosters an interoperative ecosystem for data consumers (clients) and producers (services) that is far more powerful than currently possible. It enables more applications to make sense of a broader set of data, and helps every data service and client add value to the whole ecosystem. WCF Data Services (previously known as ADO.NET Data Services), then, was the first Microsoft technology to support the Open Data Protocol in Visual Studio 2008 SP1. It provides developers with client libraries for .NET, Silverlight, AJAX, PHP and Java. Microsoft now also supports OData in SQL Server 2008 R2, Windows Azure Storage, Excel 2010 (through PowerPivot), and SharePoint 2010. Many other other applications in the works. * This post walks you through how to create an OData feed, define a shape for the data and pre-filter the data using Visual Studio 2010, WCF Data Services and the Entity Framework. A sample project is attached at the bottom of Part 2 of this post. Pre-filtering and shaping OData feeds using WCF Data Services and the Entity Framework - Part 2 Create the Web Application File –› New –› Project, Select “ASP.NET Empty Web Application” Add the Entity Data Model Right click on the Web Application in the Solution Explorer and select “Add New Item..” Select “ADO.NET Entity Data Model” under "Data”. Name the Model “Northwind” and click “Add”.   In the “Choose Model Contents”, select “Generate Model From Database” and click “Next”   Define a connection to your database containing the Northwind database in the next screen. We are going to expose the Products table through our OData feed. Select “Products” in the “Choose your Database Object” screen.   Click “Finish”. We are done creating our Entity Data Model. Save the Northwind.edmx file created. Add the WCF Data Service Right click on the Web Application in the Solution Explorer and select “Add New Item..” Select “WCF Data Service” from the list and call the service “DataService” (creative, huh?). Click “Add”.   Enable Access to the Data Service Open the DataService.svc.cs class. The class is well commented and instructs us on the next steps. public class DataService : DataService< /* TODO: put your data source class name here */ > { // This method is called only once to initialize service-wide policies. public static void InitializeService(DataServiceConfiguration config) { // TODO: set rules to indicate which entity sets and service operations are visible, updatable, etc. // Examples: // config.SetEntitySetAccessRule("MyEntityset", EntitySetRights.AllRead); // config.SetServiceOperationAccessRule("MyServiceOperation", ServiceOperationRights.All); config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2; } } Replace the comment that starts with “/* TODO:” with “NorthwindEntities” (the entity container name of the Model we created earlier).  WCF Data Services is initially locked down by default, FTW! No data is exposed without you explicitly setting it. You have explicitly specify which Entity sets you wish to expose and what rights are allowed by using the SetEntitySetAccessRule. The SetServiceOperationAccessRule on the other hand sets rules for a specified operation. Let us define an access rule to expose the Products Entity we created earlier. We use the EnititySetRights.AllRead since we want to give read only access. Our modified code is shown below. public class DataService : DataService<NorthwindEntities> { public static void InitializeService(DataServiceConfiguration config) { config.SetEntitySetAccessRule("Products", EntitySetRights.AllRead); config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2; } } We are done setting up our ODataFeed! Compile your project. Right click on DataService.svc and select “View in Browser” to see the OData feed. To view the feed in IE, you must make sure that "Feed Reading View" is turned off. You set this under Tools -› Internet Options -› Content tab.   If you navigate to “Products”, you should see the Products feed. Note also that URIs are case sensitive. ie. Products work but products doesn’t.   Filtering our data OData has a set of system query operations you can use to perform common operations against data exposed by the model. For example, to see only Products in CategoryID 2, we can use the following request: /DataService.svc/Products?$filter=CategoryID eq 2 At the time of this writing, supported operations are $orderby, $top, $skip, $filter, $expand, $format†, $select, $inlinecount. Pre-filtering our data using Query Interceptors The Product feed currently returns all Products. We want to change that so that it contains only Products that have not been discontinued. WCF introduces the concept of interceptors which allows us to inject custom validation/policy logic into the request/response pipeline of a WCF data service. We will use a QueryInterceptor to pre-filter the data so that it returns only Products that are not discontinued. To create a QueryInterceptor, write a method that returns an Expression<Func<T, bool>> and mark it with the QueryInterceptor attribute as shown below. [QueryInterceptor("Products")] public Expression<Func<Product, bool>> OnReadProducts() { return o => o.Discontinued == false; } Viewing the feed after compilation will only show products that have not been discontinued. We also confirm this by looking at the WHERE clause in the SQL generated by the entity framework. SELECT [Extent1].[ProductID] AS [ProductID], ... ... [Extent1].[Discontinued] AS [Discontinued] FROM [dbo].[Products] AS [Extent1] WHERE 0 = [Extent1].[Discontinued] Other examples of Query/Change interceptors can be seen here including an example to filter data based on the identity of the authenticated user. We are done pre-filtering our data. In the next part of this post, we will see how to shape our data. Pre-filtering and shaping OData feeds using WCF Data Services and the Entity Framework - Part 2 Foot Notes * http://msdn.microsoft.com/en-us/data/aa937697.aspx † $format did not work for me. The way to get a Json response is to include the following in the  request header “Accept: application/json, text/javascript, */*” when making the request. This is easily done with most JavaScript libraries.

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• Find More Streaming TV Online with Clicker.tv

  - by DigitalGeekery

  Looking for a way to access more of your favorite TV Shows and other online entertainment? Today we’ll take a look at Clicker.tv which offers an awesome way to find tons of TV programs and movies. Clicker.tv Clicker.tv is an HTML5 web application that indexes both free and premium content from sources like Hulu, Netflix, Amazon, iTunes, and more. Some movies or episodes, such as those from Netflix and Amazon.com’s Video on Demand, will require viewers to have a membership, or pay a fee to access content. There is also a Clicker.tv app for Boxee.   Navigation Navigating in Clicker.tv is rather easy with your keyboard. Directional Keys: navigate up, down, left, and right. Enter: make a selection Backspace: return to previous screen Escape: return to the Clicker.tv home screen. Note: You can also navigate through Clicker.tv with your PC remote. Recommended Browsers Firefox 3.6 + Safari 4.0 + Internet Explorer 8 + Google Chrome Note: You’ll need the latest version of Flash installed to play the majority of content. Earlier versions of the above browsers may work, but for full keyboard functionality, stick with the recommendations. Using Clicker.tv The first time you go to Clicker.tv, (link below) you’ll be met with a welcome screen and some helpful hints. Click Enter when finished.   The Home screen feature Headliners, Trending Shows, and Trending Episodes. You can scroll through the different options and category links along the left side.   The Search link pulls up an onscreen keyboard so you can enter search terms with a remote as well as a keyboard. Type in your search terms and matching items are displayed on the screen.   You can also browse by a wide variety of categories. Select TV to browse only available TV programs. Or, browse only Movies in the movie category. There are also links for Web content and Music.   Creating an Account You can access all Clicker.tv content without an account, but a Clicker account allows users to create playlists and subscribe to shows and have them automatically added to their playlist. You’ll need to go to Clicker.com and create an account. You’ll find the link at the upper right of the page. Enter a username, password and email address. There also an option to link with Facebook, or you can simply Skip this step.   Go to Clicker.tv and sign in. You can manually type in your credentials or use the onscreen keyboard with your remote.   Settings If you’d prefer not to display content from premium sites or Netflix, you can remove them through the Settings. Toggle Amazon, iTunes and Netflix on or off.   Watching Episodes To watch an episode, select the image to begin playing from the default source, or select one of the other options. You can see in the example below that you can choose to watch the episode from Fox, Hulu, or Amazon Video on Demand.   Your episode will then launch and begin playing from your chosen source. If you choose a premium content source such as iTunes or Amazon’s VOD, you’ll be taken to the Amazon’s website or iTunes and prompted to purchase the content.   Playlists Once you’ve created an account and signed in, you can begin adding Shows to your playlist. Choose a series and select Add to Playlist.   You’ll see in the example below that Family Guy has been Added and the number 142 is shown next to the playlist icon to indicate that 142 episodes has been added to your playlist. Underneath the listings for each episode in your playlist you can mark as Watched, or Remove individual episodes.   You can also view the playlist or make any changes from the Clicker.com website. Click on “Playlist” on the top right of the Clicker.com site to access your playlists. You can select individual episodes from your playlists, remove them, or mark them as watched or unwatched. Clicker.TV and Boxee Boxee offers a Clicker.TV app that features a limited amount of the Clicker.TV content. You’ll find Clicker.TV located in the Boxee Apps Library. Select the Clicker App and then choose Start. From the Clicker App interface you can search or browse for available content. Select an episode you’d like to view… Then select play in the pop up window. You can also add it to your Boxee queue, share it, or add a shortcut, just as you can from other Boxee apps. When you click play your episode will launch and begin playing in Boxee. Conclusion Clicker.TV is currently still in Beta and has some limitations. Typical remotes won’t work completely in all external websites. So, you’ll still need a keyboard to be able to perform some operations such as switching to full screen mode. The Boxee app offers a more fully remote friendly environment, but unfortunately lacks a good portion of the Clicker.tv content. As with many content sites, availability of certain programming may be limited by your geographic location. Want to add Clicker.TV functionality to Windows Media Center? You can do so through the Boxee Integration for Windows 7 Media Center plug-in. Clicker.tv Clicker.com Similar Articles Productive Geek Tips Share Digital Media With Other Computers on a Home Network with Windows 7Stream Music and Video Over the Internet with Windows Media Player 12Listen to Online Radio with AntennaEnable Media Streaming in Windows Home Server to Windows Media PlayerNorton Internet Security 2010 [Review] 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 HippoRemote Pro 2.2 Xobni Plus for Outlook All My Movies 5.9 CloudBerry Online Backup 1.5 for Windows Home Server Nice Websites To Watch TV Shows Online 24 Million Sites Windows Media Player Glass Icons (icons we like) How to Forecast Weather, without Gadgets Outlook Tools, one stop tweaking for any Outlook version Zoofs, find the most popular tweeted YouTube videos

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• Analytic functions – they’re not aggregates

  - by Rob Farley

  SQL 2012 brings us a bunch of new analytic functions, together with enhancements to the OVER clause. People who have known me over the years will remember that I’m a big fan of the OVER clause and the types of things that it brings us when applied to aggregate functions, as well as the ranking functions that it enables. The OVER clause was introduced in SQL Server 2005, and remained frustratingly unchanged until SQL Server 2012. This post is going to look at a particular aspect of the analytic functions though (not the enhancements to the OVER clause). When I give presentations about the analytic functions around Australia as part of the tour of SQL Saturdays (starting in Brisbane this Thursday), and in Chicago next month, I’ll make sure it’s sufficiently well described. But for this post – I’m going to skip that and assume you get it. The analytic functions introduced in SQL 2012 seem to come in pairs – FIRST_VALUE and LAST_VALUE, LAG and LEAD, CUME_DIST and PERCENT_RANK, PERCENTILE_CONT and PERCENTILE_DISC. Perhaps frustratingly, they take slightly different forms as well. The ones I want to look at now are FIRST_VALUE and LAST_VALUE, and PERCENTILE_CONT and PERCENTILE_DISC. The reason I’m pulling this ones out is that they always produce the same result within their partitions (if you’re applying them to the whole partition). Consider the following query: SELECT     YEAR(OrderDate),     FIRST_VALUE(TotalDue)         OVER (PARTITION BY YEAR(OrderDate)               ORDER BY OrderDate, SalesOrderID               RANGE BETWEEN UNBOUNDED PRECEDING                         AND UNBOUNDED FOLLOWING),     LAST_VALUE(TotalDue)         OVER (PARTITION BY YEAR(OrderDate)               ORDER BY OrderDate, SalesOrderID               RANGE BETWEEN UNBOUNDED PRECEDING                         AND UNBOUNDED FOLLOWING),     PERCENTILE_CONT(0.95)         WITHIN GROUP (ORDER BY TotalDue)         OVER (PARTITION BY YEAR(OrderDate)),     PERCENTILE_DISC(0.95)         WITHIN GROUP (ORDER BY TotalDue)         OVER (PARTITION BY YEAR(OrderDate)) FROM Sales.SalesOrderHeader ; This is designed to get the TotalDue for the first order of the year, the last order of the year, and also the 95% percentile, using both the continuous and discrete methods (‘discrete’ means it picks the closest one from the values available – ‘continuous’ means it will happily use something between, similar to what you would do for a traditional median of four values). I’m sure you can imagine the results – a different value for each field, but within each year, all the rows the same. Notice that I’m not grouping by the year. Nor am I filtering. This query gives us a result for every row in the SalesOrderHeader table – 31465 in this case (using the original AdventureWorks that dates back to the SQL 2005 days). The RANGE BETWEEN bit in FIRST_VALUE and LAST_VALUE is needed to make sure that we’re considering all the rows available. If we don’t specify that, it assumes we only mean “RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW”, which means that LAST_VALUE ends up being the row we’re looking at. At this point you might think about other environments such as Access or Reporting Services, and remember aggregate functions like FIRST. We really should be able to do something like: SELECT     YEAR(OrderDate),     FIRST_VALUE(TotalDue)         OVER (PARTITION BY YEAR(OrderDate)               ORDER BY OrderDate, SalesOrderID               RANGE BETWEEN UNBOUNDED PRECEDING                         AND UNBOUNDED FOLLOWING) FROM Sales.SalesOrderHeader GROUP BY YEAR(OrderDate) ; But you can’t. You get that age-old error: Msg 8120, Level 16, State 1, Line 5 Column 'Sales.SalesOrderHeader.OrderDate' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause. Msg 8120, Level 16, State 1, Line 5 Column 'Sales.SalesOrderHeader.SalesOrderID' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause. Hmm. You see, FIRST_VALUE isn’t an aggregate function. None of these analytic functions are. There are too many things involved for SQL to realise that the values produced might be identical within the group. Furthermore, you can’t even surround it in a MAX. Then you get a different error, telling you that you can’t use windowed functions in the context of an aggregate. And so we end up grouping by doing a DISTINCT. SELECT DISTINCT     YEAR(OrderDate),         FIRST_VALUE(TotalDue)              OVER (PARTITION BY YEAR(OrderDate)                   ORDER BY OrderDate, SalesOrderID                   RANGE BETWEEN UNBOUNDED PRECEDING                             AND UNBOUNDED FOLLOWING),         LAST_VALUE(TotalDue)             OVER (PARTITION BY YEAR(OrderDate)                   ORDER BY OrderDate, SalesOrderID                   RANGE BETWEEN UNBOUNDED PRECEDING                             AND UNBOUNDED FOLLOWING),     PERCENTILE_CONT(0.95)          WITHIN GROUP (ORDER BY TotalDue)         OVER (PARTITION BY YEAR(OrderDate)),     PERCENTILE_DISC(0.95)         WITHIN GROUP (ORDER BY TotalDue)         OVER (PARTITION BY YEAR(OrderDate)) FROM Sales.SalesOrderHeader ; I’m sorry. It’s just the way it goes. Hopefully it’ll change the future, but for now, it’s what you’ll have to do. If we look in the execution plan, we see that it’s incredibly ugly, and actually works out the results of these analytic functions for all 31465 rows, finally performing the distinct operation to convert it into the four rows we get in the results. You might be able to achieve a better plan using things like TOP, or the kind of calculation that I used in http://sqlblog.com/blogs/rob_farley/archive/2011/08/23/t-sql-thoughts-about-the-95th-percentile.aspx (which is how PERCENTILE_CONT works), but it’s definitely convenient to use these functions, and in time, I’m sure we’ll see good improvements in the way that they are implemented. Oh, and this post should be good for fellow SQL Server MVP Nigel Sammy’s T-SQL Tuesday this month.

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• Agile Awakenings and the Rules of Agile

  - by Robert May

  For those that care, you can read my history of management and technology to understand why I think I’m qualified to talk about this at all.  It’s boring, so feel free to skip it. Awakenings I first started to play around with the idea of “agile” in 2004 or 2005.  I found a book on the Rational Unified Process that I thought was good, and attempted to implement parts of it.  I thought I was agile, but really, it wasn’t.   I still didn’t understand the concept of a team.  I still wanted to tell the team what to do and how to get it done.  I still thought I was smarter than the team. After that job, I started work on another project and began helping that team.  The first few months were really rough.  We were implementing Scrum, which was relatively new to everyone on the team, and, quite frankly, I was doing a poor job of it.  I was trying to micro-manage every aspect of the teams work, and we were all miserable. The moment of change came when the senior architect bailed on the project.  His comment to me was: “This isn’t Agile.  Where are the stand-ups?  Where are the stories?”  He was dead on, and I finally woke up.  I finally realized that I was the problem!  I wasn’t trusting the team.  I wasn’t helping the team.  I was being a manager. Like many (most?), I was claiming to be Agile and use Scrum, but I wasn’t in fact following the rules Scrum.  Since then, I’ve done a lot of studying, hands on practice, coaching of many different teams, and other learning around Scrum, and I have discovered that Scrum has some rules that must be followed for success, even though the process is about continuous improvement. I’ve been practicing Scrum right for about 4 years now and have helped multiple teams implement it successfully, so what you’re about to get is based on experience, rather than just theory. The Rules of Scrum In my experience, what I’ve found is that most companies that claim to be doing Scrum or Agile are actually NOT doing either.  This stems largely because they think that they can “adopt the rules of Agile that fit their organization.”  Sadly, many of them think that this means they can adopt iterations (sprints) and not much else.  Either that, or they think they can do whatever they want, or were doing before, and call it Scrum.  This is simply not true. Here are some rules that must be followed for you to really be doing Scrum.  I’ll go into detail on each one of these posts in future blog posts and update links here.  My intent is that this will help other teams implementing scrum to see more success. Agile does not allow you to do whatever you want A Product Owner is required A ScrumMaster is required The team must function as a Team, and QA must be part of the team Support from upper management is required A prioritized product backlog is required A prioritized sprint backlog is required Release planning is required Complete spring planning is required Showcases are required Velocity must be measured Retrospectives are required Daily stand-ups are required Visibility is absolutely required For now, I think that’s enough, although I reserve the right to add more.  If you’re breaking any of these rules, you’re probably not doing Scrum.  There are exceptions to these rules, but until you have practiced Scrum for a while, you don’t know what those exceptions are. Breaking the Rules Many teams break these rules because they are the ones that expose the most pain.  Scrum is not Advil.  It’s not intended to mask the pain, its intended to cure it.  Let me explain that analogy a bit more.  Recently, my 7 year old son broke his arm, quite severely (see the X-Ray to the right).  That caused him a great deal of pain.  We went first to one doctor, and after viewing the X-Ray, they determined that there was no way that they’d cast the arm at their location.  It was simply too bad of a break for them to deal with.  They did, however, give him some Advil for the pain and put a splint on his arm to stabilize the broken bones.  Within minutes, he was feeling much better.  Had we been stupid, we could have gone home and he’d have been just as happy as ever . . . until the pain medication wore off or one of his siblings touched the splint.  Then, all of that pain would come right back to the top.  Sure, he could make it go away by just taking more Advil and moving the splint out of the way, but that wasn’t going to fix the problem permanently. We ended up in an emergency room with a doctor who could fix his arm.  However, we were warned that the fix was going to be VERY painful, and it was.  Even with heavy sedation (Propofol), my son was in enough pain that he squirmed and wiggled trying to get his arm away from the doctor.  He had to endure this pain in order to have a functional arm. But the setting wasn’t the end.  He had to have several casts, had to have it re-broken once, since the first setting didn’t take and finally was given a clean bill of health. Agile implementation is much like this story.  Agile was developed as a result of people recognizing that the development methodologies that were currently in place simply were ineffective.  However, the fix to the broken development that’s been festering for many years is not painless.  Many people start Agile thinking that things will be wonderful.  They won’t!  Agile is about visibility, and often, it brings great pain to surface.  It causes all of the missed deadlines, the cowboy coders, the coasters, the micro-managers, the lazy, and all of the other problems that are really part of your development process now to become painfully visible to EVERYONE.  Many people don’t like this exposure.  Agile will make the pain better, but not if you remove the cast (the rules above) prematurely and start breaking the rules that expose the most pain.  The healing will take time and is not instant (like Advil).  Figuring out what the true source of pain and fixing it is very valuable to you, your team, and your company.  Remember as you’re doing this that Agile isn’t the source of the pain, it’s really just exposing it.  Find the source. My recommendation is that ALL of these rules are followed for a minimum of six months, and preferably for an entire year, before you decide to break any of these rules.  Get a few good releases under your belt.  Figure out what your velocity is and start firing as a team.  Chances are, after you see agile really in action, you won’t want to break the rules because you’ll see their value. More Reading Jean Tabaka recently published a list of 78 Things I Have Learned in 6 Years of Agile Coaching.  Highly recommended. Technorati Tags: Agile,Scrum,Rules

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• Change or Reset Windows Password from a Ubuntu Live CD

  - by Trevor Bekolay

  If you can’t log in even after trying your twelve passwords, or you’ve inherited a computer complete with password-protected profiles, worry not – you don’t have to do a fresh install of Windows. We’ll show you how to change or reset your Windows password from a Ubuntu Live CD. This method works for all of the NT-based version of Windows – anything from Windows 2000 and later, basically. And yes, that includes Windows 7. You’ll need a Ubuntu 9.10 Live CD, or a bootable Ubuntu 9.10 Flash Drive. If you don’t have one, or have forgotten how to boot from the flash drive, check out our article on creating a bootable Ubuntu 9.10 flash drive. The program that lets us manipulate Windows passwords is called chntpw. The steps to install it are different in 32-bit and 64-bit versions of Ubuntu. Installation: 32-bit Open up Synaptic Package Manager by clicking on System at the top of the screen, expanding the Administration section, and clicking on Synaptic Package Manager. chntpw is found in the universe repository. Repositories are a way for Ubuntu to group software together so that users are able to choose if they want to use only completely open source software maintained by Ubuntu developers, or branch out and use software with different licenses and maintainers. To enable software from the universe repository, click on Settings > Repositories in the Synaptic window. Add a checkmark beside the box labeled “Community-maintained Open Source software (universe)” and then click close. When you change the repositories you are selecting software from, you have to reload the list of available software. In the main Synaptic window, click on the Reload button. The software lists will be downloaded. Once downloaded, Synaptic must rebuild its search index. The label over the text field by the Search button will read “Rebuilding search index.” When it reads “Quick search,” type chntpw in the text field. The package will show up in the list. Click on the checkbox near the chntpw name. Click on Mark for Installation. chntpw won’t actually be installed until you apply the changes you’ve made, so click on the Apply button in the Synaptic window now. You will be prompted to accept the changes. Click Apply. The changes should be applied quickly. When they’re done, click Close. chntpw is now installed! You can close Synaptic Package Manager. Skip to the section titled Using chntpw to reset your password. Installation: 64-bit The version of chntpw available in Ubuntu’s universe repository will not work properly on a 64-bit machine. Fortunately, a patched version exists in Debian’s Unstable branch, so let’s download it from there and install it manually. Open Firefox. Whether it’s your preferred browser or not, it’s very readily accessible in the Ubuntu Live CD environment, so it will be the easiest to use. There’s a shortcut to Firefox in the top panel. Navigate to http://packages.debian.org/sid/amd64/chntpw/download and download the latest version of chntpw for 64-bit machines. Note: In most cases it would be best to add the Debian Unstable branch to a package manager, but since the Live CD environment will revert to its original state once you reboot, it’ll be faster to just download the .deb file. Save the .deb file to the default location. You can close Firefox if desired. Open a terminal window by clicking on Applications at the top-left of the screen, expanding the Accessories folder, and clicking on Terminal. In the terminal window, enter the following text, hitting enter after each line: cd Downloadssudo dpkg –i chntpw* chntpw will now be installed. Using chntpw to reset your password Before running chntpw, you will have to mount the hard drive that contains your Windows installation. In most cases, Ubuntu 9.10 makes this simple. Click on Places at the top-left of the screen. If your Windows drive is easily identifiable – usually by its size – then left click on it. If it is not obvious, then click on Computer and check out each hard drive until you find the correct one. The correct hard drive will have the WINDOWS folder in it. When you find it, make a note of the drive’s label that appears in the menu bar of the file browser. If you don’t already have one open, start a terminal window by going to Applications > Accessories > Terminal. In the terminal window, enter the commands cd /medials pressing enter after each line. You should see one or more strings of text appear; one of those strings should correspond with the string that appeared in the title bar of the file browser earlier. Change to that directory by entering the command cd <hard drive label> Since the hard drive label will be very annoying to type in, you can use a shortcut by typing in the first few letters or numbers of the drive label (capitalization matters) and pressing the Tab key. It will automatically complete the rest of the string (if those first few letters or numbers are unique). We want to switch to a certain Windows directory. Enter the command: cd WINDOWS/system32/config/ Again, you can use tab-completion to speed up entering this command. To change or reset the administrator password, enter: sudo chntpw SAM SAM is the file that contains your Windows registry. You will see some text appear, including a list of all of the users on your system. At the bottom of the terminal window, you should see a prompt that begins with “User Edit Menu:” and offers four choices. We recommend that you clear the password to blank (you can always set a new password in Windows once you log in). To do this, enter “1” and then “y” to confirm. If you would like to change the password instead, enter “2”, then your desired password, and finally “y” to confirm. If you would like to reset or change the password of a user other than the administrator, enter: sudo chntpw –u <username> SAM From here, you can follow the same steps as before: enter “1” to reset the password to blank, or “2” to change it to a value you provide. And that’s it! Conclusion chntpw is a very useful utility provided for free by the open source community. It may make you think twice about how secure the Windows login system is, but knowing how to use chntpw can save your tail if your memory fails you two or eight times! Similar Articles Productive Geek Tips Reset Your Ubuntu Password Easily from the Live CDChange Your Forgotten Windows Password with the Linux System Rescue CDHow to Create and Use a Password Reset Disk in Windows Vista & Windows 7Reset Your Forgotten Password the Easy Way Using the Ultimate Boot CD for WindowsHow to install Spotify in Ubuntu 9.10 using Wine 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 DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Add a Custom Title in IE using Spybot or Spyware Blaster When You Need to Hail a Taxi in NYC Live Map of Marine Traffic NoSquint Remembers Site Specific Zoom Levels (Firefox) New Firefox release 3.6.3 fixes 1 Critical bug Dark Side of the Moon (8-bit)

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• Automating Form Login

  - by Greg_Gutkin

  Introduction A common task in configuring a web application for proxying in Pagelet Producer is setting up form autologin. PP provides a wizard-like tool for detecting the login form fields, but this is usually only the first step in configuring this feature. If the generated configuration doesn't seem to work, some additional manual modifications will be needed to complete the setup. This article will try to guide you through this process while steering you away from common pitfalls. For the purposes of this article, let's assume the following characteristics about your environment: Web Application Base URL: http://host/app (configured as Resource Source URL in PP) Pagelet Producer Base URL: http://pp/pagelets Form Field Auto-Detection Form Autologin is configured in the PP Admin UI under resource_name/Autologin/Form Login. First, you'll enter the URL to the login form under "Login Form Identification". This will enable the admin wizard to connect to and display the login page. Caution: RedirectsMake sure the entered URL matches what you see in the browser's address bar, when the application login page is displayed. For example, even though you may be able to reach the login page by simply typing http://host/app, the URL you end up on may change to http://host/app/login via browser redirect(s).The second URL is the one you will want to use. Caution: External Login ServersThe login page may actually come from a different server than the application you are trying to proxy. For example, you may notice that the login page URL changes to http://hostB/appB. This is common when external SSO products are involved. There are two ways of dealing with this situation. One is to configure Pagelet Producer to participate in SSO. This approach is out of scope of this article and is discussed in a separate whitepaper (TODO add link). The second approach is to use the autologin feature to provide stored credentials to the SSO login form. Since the login form URL is not an extension of the application base URL (PP resource URL), you will need to add a new PP resource for the SSO server and configure the login form on that resource instead of the original application resource. One side benefit of this additional resource is that it can reused for other applications relying on the same SSO server for login. After entering the login page URL (make sure dropdown says "URL"), click "Automatically Detect Form Fields". This will bring up the web app's login page in a new browser window. Fill it out and submit it as you would normally. If everything goes right, Pagelet Producer will intercept the submitted values and fill out all the needed configuration data in the Admin UI. If the login form window doesn't close or configuration data doesn't get filled in, you may have not entered the login page URL correctly. Review the two cautionary notes above and make any necessary changes. If the form fields got filled automatically, it's time to save the configuration and test it out. If you can access a protected area of the backend application via a proxied PP URL without filling out its login form, then you are pretty much done with login form configuration. The only other step you will need to complete before declaring this aspect of configuration production ready is configuring form field source. You may skip to that section below. Manual Login Form Identification Let's take a closer look at Login Form Identification. This determines how Pagelet Producer recognizes login forms as such. URL The most efficient way of detecting login forms is by looking at the page URL. This method can only be used under the following conditions: Login page URL must be different from the post login application URLs. Login page URL must stay constant regardless of the path it takes to reach the page. For example, reaching the login page by going to the application base URL or to a specific protected URL must result in a redirect to the same login page URL (query string excluded). If only the query string parameters change, just leave out the query string from the configured login page URL. If either of these conditions is not fullfilled, you must switch to the RegEx approach below. RegEx If the login page URL is not uniform enough across all scenarios or is indistinguishable from other page locations, PP can be configured to recognize it by looking at the page markup itself. This is accomplished by changing the dropdown to "RegEx". If regular expressions scare you, take comfort from the fact that in most cases you won't need to enter any special regex characters. Let's look at an example: Say you have a login form that looks like <form id='loginForm' action='login?from=pageA' > <input id='user'> <input id='pass'> </form> Since this form has an id attribute, you can be reasonably sure that this login form can be uniquely identified across the web application by this snippet: "id='loginForm'". (Unless, of course your backend web application contains login forms to other apps). Since no wildcards are needed to find this snippet, you can just enter it as is into the RegEx field - no special regular expression characters needed! If the web developer who created the form wasn't kind enough to provide a unique id, you will need to look for other snippets of the page to uniquely identify it. It could be the action URL, an input field id, or some other markup fragment. You should abstain from using UI text as an identifier it may change in translated versions of the page and prevent the login page logic from working for international users. You may need to turn to regular expression wildcard syntax if no simple matches work. For more information on regular expression, refer to the Resources section. Form Submit Location Now we'll look at the form submit location. If the captured URL contains query string parameters that will likely change from one form submission to the next, you will need to change its type to RegEx. This type will tell Pagelet Producer to parse the login page for the action URL and submit to the value found. The regular expression needs to point at the actual action URL with its first grouping expression. Taking the example form definition above, the form submit location regex would be: action='(.*?)' The parentheses are used to identify the actual action URL, while the rest of the expression provides the context for finding it. Expression .*? is a so-called reluctant wildcard that matches any character excluding the single quote that follows. See Resources section below for further information on regular expressions. Manual Form Field Detection If the Admin UI form field detection wizard fails to populate login form configuration page, you will have to enter the fields by hand. Use a built-in browser developer tool or addon (e.g. Firebug) to inspect the form element and its children input elements. For each input element (including hidden elements), create an entry under Form Fields. Change its Source according to the next section. Form Field Source Change the source of any of the fields not exposed to the users of the login form (i.e. hidden fields) to "Generated". This means Pagelet Producer will just use the values returned by the web app rather than supplying values it stored. For fields that contain sensitive data or vary from user to user (e.g. username & password), change the source to User (Credential) Vault. Logging Support To help you troubleshoot you autologin configuration, PP provides some useful logging support. To turn on detailed logging for the autologin feature, navigate to Settings in Admin UI. Under Logging, change the log level for AutoLogin to Finest. Known Limitations Autologin feature may not work as expected if login form fields (not just the values, but the DOM elements themselves) are generated dynamically by client side JavaScript. Resources RegEx RegEx Reference from Java RegEx Test Tool

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• The hidden cost of interrupting knowledge workers

  - by Piet

  The November issue of pragpub has an interesting article on interruptions. The article is written by Brian Tarbox, who also mentions the article on his blog. I like the subtitle: ‘Simple Strategies for Avoiding Dumping Your Mental Stack’. Brian talks about the effective cost of interrupting a ‘knowledge worker’, often with trivial questions or distractions. In the eyes of the interruptor, the interruption only costs the time the interrupted had to listen to the question and give an answer. However, depending on what the interrupted was doing at the time, getting fully immersed in their task again might take up to 15-20 minutes. Enough interruptions might even cause a knowledge worker to mentally call it a day. According to this article interruptions can consume about 28% of a knowledge worker’s time, translating in a $588 billion loss for US companies each year. Looking for a new developer to join your team? Ever thought about optimizing your team’s environment and the way they work instead? Making non knowledge workers aware You can’t. Well, I haven’t succeeded yet. And believe me: I’ve tried. When you’ve got a simple way to really increase your productivity (’give me 2 hours of uninterrupted time a day’) it wouldn’t be right not to tell your boss or team-leader about it. The problem is: only productive knowledge workers seem to understand this. People who don’t fall into this category just seem to think you’re joking, being arrogant or anti-social when you tell them the interruptions can really have an impact on your productivity. Also, knowledge workers often work in a very concentrated mental state which is described here as: It is the same mindfulness as ecstatic lovemaking, the merging of two into a fluidly harmonious one. The hallmark of flow is a feeling of spontaneous joy, even rapture, while performing a task. Yes, coding can be addictive and if you’re interrupting a programmer at the wrong moment, you’re effectively bringing down a junkie from his high in just a few seconds. This can result in seemingly arrogant, almost aggressive reactions. How to make people aware of the production-cost they’re inflicting: I’ve been often pondering that question myself. The article suggests that solutions based on that question never seem to work. To be honest: I’ve never even been able to find a half decent solution for this question. People who are not in this situations just don’t understand the issue, no matter how you try to explain it. Fun (?) thing I’ve noticed: Programmers or IT people in general who don’t get this are often the kind of people who just don’t get anything done. Interrupt handling (interruption management?) IRL Have non-urgent questions handled in a non-interruptive way It helps a bit to educate people into using non-interruptive ways to ask questions: “duh, I have no idea, but I’m a bit busy here now could you put it in an email so I don’t forget?”. Eventually, a considerable amount of people will skip interrupting you and just send an email right away. Some stubborn-headed people however will continue to just interrupt you, saying “you’re 10 meters from my desk, why can’t we just talk?”. Just remember to disable your email notifications, it can be hard to resist opening your email client when you know a new email just arrived. Use Do Not Disturb signals When working in a group of programmers, often the unofficial sign you can only be interrupted for something important is to put on headphones. And when the environment is quiet enough, often people aren’t even listening to music. Otherwise music can help to block the indirect distractions (someone else talking on the phone or tapping their feet). You might get a “they’re all just surfing and listening to music”-reaction from outsiders though. Peopleware talks about a team where the no-interruption sign was placing a shawl on the desk. If I remember correctly, I am unable to locate my copy of this really excellent must-read book. If you have all standardized on the same IM tool, maybe that tool has a ‘do not disturb’ setting. Also some phone-systems have a ‘DND’ (do not disturb) setting. Hide Brian offers a number of good suggestions, some obvious like: hide away somewhere they can’t find you. Not sure how long it’ll be till someone thinks you’re just taking a nap somewhere though. Also, this often isn’t possible or your boss might not understand this. And if you really get caught taking a nap, make sure to explain that your were powernapping. Counter-act interruptions Another suggestion he offers is when you’re being interrupted to just hold up your hand, blocking the interruption, and at least giving you time to finish your sentence or your block/line of code. The last suggestion works more as a way to make it obvious to the interruptor that they really are interrupting your work and to offload some of the cost on the interruptor. In practice, this can also helps you cool down a bit so you don’t start saying nasty things to the interruptor. Unfortunately I’ve sometimes been confronted with people who just ignore this signal and keep talking, as if they’re sure that whatever they’ve got to say is really worth listening to and without a doubt more important than anything you might be doing. This behaviour usually leaves me speechless (not good when someone just asked a question). I’ve noticed that these people are usually also the first to complain when being interrupted themselves. They’re generally not very liked as colleagues, so try not to imitate their behaviour. TDD as a way to minimize recovery time I don’t like Test Driven Development. Mainly for only one reason: It interrupts flow. At least, that’s what it does for me, but maybe I’m just not grown used to TDD yet. BUT a positive effect TDD has on me when I have to work in an interruptive environment and can’t really get into the ‘flow’ (also supposedly called ‘the zone’ by software developers, although I’ve never heard it 1st hand), TDD helps me to concentrate on the tasks at hand and helps me to get back at work after an interruption. I feel when using TDD, I can get by without the need for being totally ‘in’ the project and I can be reasonably productive without obtaining ‘flow’. Do you have a suggestion on how to make people aware of the concept of ‘flow’ and the cost of interruptions? (without looking like an arrogant ass or a weirdo)

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• Creating and maintaining Orchard translations

  - by Bertrand Le Roy

  Many volunteers have already stepped up to provide translations for Orchard. There are many challenges to overcome with translating such a project. Orchard is a very modular CMS, so the translation mechanism needs to account for the core as well as first and third party modules and themes. Another issue is that every new version of Orchard or of a module changes some localizable strings and adds new ones as others enter obsolescence. In order to address those problems, I've built a small Orchard module that automates some of the most complex tasks that maintaining a translation implies. In this post, I'll walk you through the operations I had to do to update the French translation for Orchard 1.0. In order to make sure you translate all the first party modules, I would recommend that you start from a full source code enlistment. The reason is that I'll show how you can extract the default en-US translation from any source code enlistment. That enables you to create a translation that is even more up-to-date than what is currently on the site. Alternatively, you could start by downloading the current en-US translation. If you decide to do so, just skip the relevant paragraphs. First, let's install the Orchard Translation Manager. I'm starting from a vanilla clone of the latest in the code repository. After you've setup the site, go into the dashboard and click on Gallery. Locate the Orchard Translation Manager in the list of modules and click "Install". Once the module is installed, you need to enable its one feature by going into Configuration/Features and clicking "Enable" next to Vandelay.TranslationManager. We're done with the setup that we need in order to start our translation work. We'll now switch to the command-line and to our favorite text editor. Open a command-line on the Orchard web site folder. I found the easiest way to do this is to do a SHIFT+right-click on the Orchard.Web folder in Windows Explorer and to click "Open command window here". Type bin\orchard to enter the Orchard command-line environment. If you do a "help commands" you should see four commands in the list that came from the module we just installed: extract default translation, install translation, package translation and sync translation. First, we're going to generate the default translation. Note that it is possible to generate that default translation for a specific list of modules and themes by using the /Extensions: switch, which should facilitate the translation of third party extensions, but in this tutorial we're going to generate it for the whole of the Orchard source code. extract default translation /Output:\temp .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 should have created an Orchard.en-us.po.zip file in the temp directory. Extract that archive into an orchard.po folder under \temp. The next step depends on whether you have an existing translation that you want to update or not. If you do have an existing translation, just extract it into the same \temp\orchard.po directory. That should result in a file structure where you have the default en-US translation alongside your own. If you don't have an existing translation, just continue, the commands will be the same. We are now going to synchronize those translations (or generate the stub for a new one if you didn't start from an existing translation). sync translation /Input:\temp\orchard.po /Culture:fr-FR After this command (where you should of course substitute fr-FR with the culture you're working on), we now have updated files that contain a few useful flags. Open each of the .po files under the culture you are working on (there should be around 36) with your favorite text editor. For all the strings that are still valid in the latest version, nothing changes and you don't need to do anything. For all the strings that disappeared from the default culture, the old translation will still be there but they will be prefixed with the following comment: # Obsolete translation Conveniently, all the obsolete strings will be grouped at the end of the file. You can select all those and delete them. For all the new strings, you will see the following comment: # Untranslated string This is where the hard work begins. You'll need to translate each of those new strings by entering the translation between the quotes in: msgstr "" Don't introduce hard carriage returns in the strings, just stay on one line (your text editor should do some reasonable wrapping so this shouldn't be a big deal). Once you're done with a file, save it. Make sure, and this is very important, that your text editor is saving using the UTF-8 encoding. In Notepad, that setting can be found in the file saving dialog by doing a "Save As" rather than a plain "Save": When all the po files have been edited, you are ready to package the translation for submission (a.k.a. sending e-mail to the localization mailing list). package translation /Culture:fr-FR /Input:\temp\orchard.po /Output:\temp You should now see a Orchard.fr-FR.po.zip file in temp that is ready to be submitted. That is, once you've tested it, which can be done by deploying it into the site: install translation \temp\orchard.fr-fr.po.zip Once this is done you can go into the dashboard under Configuration/Settings and click on "Add or remove supported cultures for the site". Choose your culture and click "Add". You can go back to settings and set the default culture. Save. You may now take a tour of the application and verify that everything works as expected: And that's it really. Creating a translation for Orchard is a matter of a few hours. If you don't see a translation for your culture, please consider creating it.

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• Help me solve my problem with NPR Media Player

  - by Calcipher

  First of, let me apologize for this getting a bit technical. Several weeks ago, I found that while using NPR's media player (e.g. click on 'Listen to the Show' - this is what I've been using as a test) the stream would suddenly halt after a minute or three. I could not get the stream to restart without reloading the page. Now, I assumed this was an issue with NPR's player and Linux (or just a bug in their stuff in general) so I began to dig, the following is what I have tried to date (please note, the tldr; option is to skip to the latest thing as I think I know what is causing the problem). Note: All testing has been done, for consistency purposes, on a clean install of Chromium with no pluggins running. My machine is Ubuntu 10.10x64. First thing I always try, I disabled all firewall stuff on the system (UFW, default deny all, allow ssh). No change, firewall back up for all additional tests unless otherwise noted. In any case, UFW is stateful, so connections it started on a non-specified on different ports will continue to work. I deleted my ~/.macromeda and ~/.adobe folders, restarted (just to be sure) and tried. Program still froze. I decided the problem might be with my install of flash, so I purged the version I had (and the home folders again). I installed the x64 version of flash from a PPA. This had no effect. I decided that the problem might be with the version of flash, so I purged the x64 version and installed the standard x32 version that comes with Ubuntu. No luck. Back to the x64 version for consistency, I decided to set up a 64-bit mini 'clone' of my system in VirtualBox. I was able to run the media player with no problem. I rsynced (in archive mode) my home directory from my real machine to the virtual machine (with bridged networking, so it was fully visible on the network). I also used a few tricks to install ALL of the same software (and repositories) from the real machine to the virtual machine. I was still able to listen to the player. I decided that the problem was with my install (after all, it had gone through two major version upgrades). As I have /home/ on a separate partition it was easy to reinstall and use the same trick from #6 to have my system up and running again within about an hour. I continue to have issues with the NPR Media Player. By this point the weekend had come. At work, I use a wired connection while at home I use a wireless connection. For some reason I forgot that I was having problems and used the NPR Media Player over the weekend. Low and behold it worked just fine at home on wireless (note: for various reasons, I could not test this on wired at home). Following from #6, I decided that the problem was either something with the network at work or still something with my account. As the latter was easier to test, I created a new account on my system and used that at work. The Media Player worked. At a loss, I decided to watch the traffic with tshark (the text based brother of wireshark) - X's to protect the innocent, I am the XXX.24.200.XXX: sudo tshark -i eth0 -p -t a -R "ip.addr == XXX.24.200.XXX && ip.addr == XXX.166.98.XXX" As you would expect, there were tons and tons of packets, but each and every time the player froze, this is what I got 08:42:20.679200 XXX.166.98.XXX - XXX.24.200.XXX TCP macromedia-fcs 56371 [PSH, ACK] Seq=817686 Ack=6 Win=65535 Len=1448 TSV=495713325 TSER=396467 08:42:20.718602 XXX.24.200.XXX - XXX.166.98.XXX TCP [TCP ZeroWindow] 56371 macromedia-fcs [ACK] Seq=6 Ack=819134 Win=0 Len=0 TSV=396475 TSER=495713325 08:42:21.050183 XXX.166.98.XXX - XXX.24.200.XXX TCP [TCP ZeroWindowProbe] macromedia-fcs 56371 [ACK] Seq=819134 Ack=6 Win=65535 Len=1 TSV=495713362 TSER=396475 08:42:21.050221 XXX.24.200.XXX - XXX.166.98.XXX TCP [TCP ZeroWindowProbeAck] [TCP ZeroWindow] 56371 macromedia-fcs [ACK] Seq=6 Ack=819134 Win=0 Len=0 TSV=396508 TSER=495713362 08:42:21.680548 XXX.166.98.XXX - XXX.24.200.XXX TCP [TCP ZeroWindowProbe] macromedia-fcs 56371 [ACK] Seq=819134 Ack=6 Win=65535 Len=1 TSV=495713425 TSER=396508 08:42:21.680605 XXX.24.200.XXX - XXX.166.98.XXX TCP [TCP ZeroWindowProbeAck] [TCP ZeroWindow] 56371 macromedia-fcs [ACK] Seq=6 Ack=819134 Win=0 Len=0 TSV=396571 TSER=495713425 08:42:22.910354 XXX.166.98.XXX - XXX.24.200.XXX TCP [TCP ZeroWindowProbe] macromedia-fcs 56371 [ACK] Seq=819134 Ack=6 Win=65535 Len=1 TSV=495713548 TSER=396571 08:42:22.910400 XXX.24.200.XXX - XXX.166.98.XXX TCP [TCP ZeroWindowProbeAck] [TCP ZeroWindow] 56371 macromedia-fcs [ACK] Seq=6 Ack=819134 Win=0 Len=0 TSV=396694 TSER=495713548 08:42:25.340458 XXX.166.98.XXX - XXX.24.200.XXX TCP [TCP ZeroWindowProbe] macromedia-fcs 56371 [ACK] Seq=819134 Ack=6 Win=65535 Len=1 TSV=495713791 TSER=396694 08:42:25.340517 XXX.24.200.XXX - XXX.166.98.XXX TCP [TCP ZeroWindowProbeAck] [TCP ZeroWindow] 56371 macromedia-fcs [ACK] Seq=6 Ack=819134 Win=0 Len=0 TSV=396937 TSER=495713791 08:42:30.170698 XXX.166.98.XXX - XXX.24.200.XXX TCP [TCP ZeroWindowProbe] macromedia-fcs 56371 [ACK] Seq=819134 Ack=6 Win=65535 Len=1 TSV=495714274 TSER=396937 08:42:30.170746 XXX.24.200.XXX - XXX.166.98.XXX TCP [TCP ZeroWindowProbeAck] [TCP ZeroWindow] 56371 macromedia-fcs [ACK] Seq=6 Ack=819134 Win=0 Len=0 TSV=397420 TSER=495714274 08:42:39.801738 XXX.166.98.XXX - XXX.24.200.XXX TCP [TCP ZeroWindowProbe] macromedia-fcs 56371 [ACK] Seq=819134 Ack=6 Win=65535 Len=1 TSV=495715237 TSER=397420 08:42:39.801784 XXX.24.200.XXX - XXX.166.98.XXX TCP [TCP ZeroWindowProbeAck] [TCP ZeroWindow] 56371 macromedia-fcs [ACK] Seq=6 Ack=819134 Win=0 Len=0 TSV=398383 TSER=495715237 08:42:59.032648 XXX.166.98.XXX - XXX.24.200.XXX TCP [TCP ZeroWindowProbe] macromedia-fcs 56371 [ACK] Seq=819134 Ack=6 Win=65535 Len=1 TSV=495717160 TSER=398383 08:42:59.032696 XXX.24.200.XXX - XXX.166.98.XXX TCP [TCP ZeroWindowProbeAck] [TCP ZeroWindow] 56371 macromedia-fcs [ACK] Seq=6 Ack=819134 Win=0 Len=0 TSV=400306 TSER=495717160 08:43:00.267721 XXX.24.200.XXX - XXX.166.98.XXX TCP 56371 macromedia-fcs [FIN, ACK] Seq=6 Ack=819134 Win=0 Len=0 TSV=400430 TSER=495717160 08:43:00.267827 XXX.24.200.XXX - XXX.166.98.XXX TCP 56371 macromedia-fcs [RST, ACK] Seq=7 Ack=819134 Win=65535 Len=0 TSV=400430 TSER=495717160 So, as you can see, my machine is sending out a ZeroWindow packet (which I think means some buffer or another filled up) which causes the Media Player to halt (unfortunately, terminally - no controls on it really do anything anymore). Any ideas, at all, what would cause this? Why only on eth0 under my main account?

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• techniques for an AI for a highly cramped turn-based tactics game

  - by Adam M.

  I'm trying to write an AI for a tactics game in the vein of Final Fantasy Tactics or Vandal Hearts. I can't change the game rules in any way, only upgrade the AI. I have experience programming AI for classic board games (basically minimax and its variants), but I think the branching factor is too great for the approach to be reasonable here. I'll describe the game and some current AI flaws that I'd like to fix. I'd like to hear ideas for applicable techniques. I'm a decent enough programmer, so I only need the ideas, not an implementation (though that's always appreciated). I'd rather not expend effort chasing (too many) dead ends, so although speculation and brainstorming are good and probably helpful, I'd prefer to hear from somebody with actual experience solving this kind of problem. For those who know it, the game is the land battle mini-game in Sid Meier's Pirates! (2004) and you can skim/skip the next two paragraphs. For those who don't, here's briefly how it works. The battle is turn-based and takes place on a 16x16 grid. There are three terrain types: clear (no hindrance), forest (hinders movement, ranged attacks, and sight), and rock (impassible, but does not hinder attacks or sight). The map is randomly generated with roughly equal amounts of each type of terrain. Because there are many rock and forest tiles, movement is typically very cramped. This is tactically important. The terrain is not flat; higher terrain gives minor bonuses. The terrain is known to both sides. The player is always the attacker and the AI is always the defender, so it's perfectly valid for the AI to set up a defensive position and just wait. The player wins by killing all defenders or by getting a unit to the city gates (a tile on the other side of the map). There are very few units on each side, usually 4-8. Because of this, it's crucial not to take damage without gaining some advantage from it. Units can take multiple actions per turn. All units on one side move before any units on the other side. Order of execution is important, and interleaving of actions between units is often useful. Units have melee and ranged attacks. Melee attacks vary widely in strength; ranged attacks have the same strength but vary in range. The main challenges I face are these: Lots of useful move combinations start with a "useless" move that gains no immediate advantage, or even loses advantage, in order to set up a powerful flank attack in the future. And, since the player units are stronger and have longer range, the AI pretty much always has to take some losses before they can start to gain kills. The AI must be able to look ahead to distinguish between sacrificial actions that provide a future benefit and those that don't. Because the terrain is so cramped, most of the tactics come down to achieving good positioning with multiple units that work together to defend an area. For instance, two defenders can often dominate a narrow pass by positioning themselves so an enemy unit attempting to pass must expose itself to a flank attack. But one defender in the same pass would be useless, and three units can defend a slightly larger pass. Etc. The AI should be able to figure out where the player must go to reach the city gates and how to best position its few units to cover the approaches, shifting, splitting, or combining them appropriately as the player moves. Because flank attacks are extremely deadly (and engineering flank attacks is key to the player strategy), the AI should be competent at moving its units so that they cover each other's flanks unless the sacrifice of a unit would give a substantial benefit. They should also be able to force flank attacks on players, for instance by threatening a unit from two different directions such that responding to one threat exposes the flank to the other. The AI should attack if possible, but sometimes there are no good ways to approach the player's position. In that case, the AI should be able to recognize this and set up a defensive position of its own. But the AI shouldn't be vulnerable to a trivial exploit where the player repeatedly opens and closes a hole in his defense and shoots at the AI as it approaches and retreats. That is, the AI should ideally be able to recognize that the player is capable of establishing a solid defense of an area, even if the defense is not currently in place. (I suppose if a good unit allocation algorithm existed, as needed for the second bullet point, the AI could run it on the player units to see where they could defend.) Because it's important to choose a good order of action and interleave actions between units, it's not as simple as just finding the best move for each unit in turn. All of these can be accomplished with a minimax search in theory, but the search space is too large, so specialized techniques are needed. I thought about techniques such as influence mapping, but I don't see how to use the technique to great effect. I thought about assigning goals to the units. This can help them work together in some limited way, and the problem of "how do I accomplish this goal?" is easier to solve than "how do I win this battle?", but assigning good goals is a hard problem in itself, because it requires knowing whether the goal is achievable and whether it's a good use of resources. So, does anyone have specific ideas for techniques that can help cleverize this AI? Update: I found a related question on Stackoverflow: http://stackoverflow.com/questions/3133273/ai-for-a-final-fantasy-tactics-like-game The selected answer gives a decent approach to choosing between alternative actions, but it doesn't seem to have much ability to look into the future and discern beneficial sacrifices from wasteful ones. It also focuses on a single unit at a time and it's not clear how it could be extended to support cooperation between units in defending or attacking.

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• The blocking nature of aggregates

  - by Rob Farley

  I wrote a post recently about how query tuning isn’t just about how quickly the query runs – that if you have something (such as SSIS) that is consuming your data (and probably introducing a bottleneck), then it might be more important to have a query which focuses on getting the first bit of data out. You can read that post here.  In particular, we looked at two operators that could be used to ensure that a query returns only Distinct rows. and The Sort operator pulls in all the data, sorts it (discarding duplicates), and then pushes out the remaining rows. The Hash Match operator performs a Hashing function on each row as it comes in, and then looks to see if it’s created a Hash it’s seen before. If not, it pushes the row out. The Sort method is quicker, but has to wait until it’s gathered all the data before it can do the sort, and therefore blocks the data flow. But that was my last post. This one’s a bit different. This post is going to look at how Aggregate functions work, which ties nicely into this month’s T-SQL Tuesday. I’ve frequently explained about the fact that DISTINCT and GROUP BY are essentially the same function, although DISTINCT is the poorer cousin because you have less control over it, and you can’t apply aggregate functions. Just like the operators used for Distinct, there are different flavours of Aggregate operators – coming in blocking and non-blocking varieties. The example I like to use to explain this is a pile of playing cards. If I’m handed a pile of cards and asked to count how many cards there are in each suit, it’s going to help if the cards are already ordered. Suppose I’m playing a game of Bridge, I can easily glance at my hand and count how many there are in each suit, because I keep the pile of cards in order. Moving from left to right, I could tell you I have four Hearts in my hand, even before I’ve got to the end. By telling you that I have four Hearts as soon as I know, I demonstrate the principle of a non-blocking operation. This is known as a Stream Aggregate operation. It requires input which is sorted by whichever columns the grouping is on, and it will release a row as soon as the group changes – when I encounter a Spade, I know I don’t have any more Hearts in my hand. Alternatively, if the pile of cards are not sorted, I won’t know how many Hearts I have until I’ve looked through all the cards. In fact, to count them, I basically need to put them into little piles, and when I’ve finished making all those piles, I can count how many there are in each. Because I don’t know any of the final numbers until I’ve seen all the cards, this is blocking. This performs the aggregate function using a Hash Match. Observant readers will remember this from my Distinct example. You might remember that my earlier Hash Match operation – used for Distinct Flow – wasn’t blocking. But this one is. They’re essentially doing a similar operation, applying a Hash function to some data and seeing if the set of values have been seen before, but before, it needs more information than the mere existence of a new set of values, it needs to consider how many of them there are. A lot is dependent here on whether the data coming out of the source is sorted or not, and this is largely determined by the indexes that are being used. If you look in the Properties of an Index Scan, you’ll be able to see whether the order of the data is required by the plan. A property called Ordered will demonstrate this. In this particular example, the second plan is significantly faster, but is dependent on having ordered data. In fact, if I force a Stream Aggregate on unordered data (which I’m doing by telling it to use a different index), a Sort operation is needed, which makes my plan a lot slower. This is all very straight-forward stuff, and information that most people are fully aware of. I’m sure you’ve all read my good friend Paul White (@sql_kiwi)’s post on how the Query Optimizer chooses which type of aggregate function to apply. But let’s take a look at SQL Server Integration Services. SSIS gives us a Aggregate transformation for use in Data Flow Tasks, but it’s described as Blocking. The definitive article on Performance Tuning SSIS uses Sort and Aggregate as examples of Blocking Transformations. I’ve just shown you that Aggregate operations used by the Query Optimizer are not always blocking, but that the SSIS Aggregate component is an example of a blocking transformation. But is it always the case? After all, there are plenty of SSIS Performance Tuning talks out there that describe the value of sorted data in Data Flow Tasks, describing the IsSorted property that can be set through the Advanced Editor of your Source component. And so I set about testing the Aggregate transformation in SSIS, to prove for sure whether providing Sorted data would let the Aggregate transform behave like a Stream Aggregate. (Of course, I knew the answer already, but it helps to be able to demonstrate these things). A query that will produce a million rows in order was in order. Let me rephrase. I used a query which produced the numbers from 1 to 1000000, in a single field, ordered. The IsSorted flag was set on the source output, with the only column as SortKey 1. Performing an Aggregate function over this (counting the number of rows per distinct number) should produce an additional column with 1 in it. If this were being done in T-SQL, the ordered data would allow a Stream Aggregate to be used. In fact, if the Query Optimizer saw that the field had a Unique Index on it, it would be able to skip the Aggregate function completely, and just insert the value 1. This is a shortcut I wouldn’t be expecting from SSIS, but certainly the Stream behaviour would be nice. Unfortunately, it’s not the case. As you can see from the screenshots above, the data is pouring into the Aggregate function, and not being released until all million rows have been seen. It’s not doing a Stream Aggregate at all. This is expected behaviour. (I put that in bold, because I want you to realise this.) An SSIS transformation is a piece of code that runs. It’s a physical operation. When you write T-SQL and ask for an aggregation to be done, it’s a logical operation. The physical operation is either a Stream Aggregate or a Hash Match. In SSIS, you’re telling the system that you want a generic Aggregation, that will have to work with whatever data is passed in. I’m not saying that it wouldn’t be possible to make a sometimes-blocking aggregation component in SSIS. A Custom Component could be created which could detect whether the SortKeys columns of the input matched the Grouping columns of the Aggregation, and either call the blocking code or the non-blocking code as appropriate. One day I’ll make one of those, and publish it on my blog. I’ve done it before with a Script Component, but as Script components are single-use, I was able to handle the data knowing everything about my data flow already. As per my previous post – there are a lot of aspects in which tuning SSIS and tuning execution plans use similar concepts. In both situations, it really helps to have a feel for what’s going on behind the scenes. Considering whether an operation is blocking or not is extremely relevant to performance, and that it’s not always obvious from the surface. In a future post, I’ll show the impact of blocking v non-blocking and synchronous v asynchronous components in SSIS, using some of LobsterPot’s Script Components and Custom Components as examples. When I get that sorted, I’ll make a Stream Aggregate component available for download.

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• The blocking nature of aggregates

  - by Rob Farley

  I wrote a post recently about how query tuning isn’t just about how quickly the query runs – that if you have something (such as SSIS) that is consuming your data (and probably introducing a bottleneck), then it might be more important to have a query which focuses on getting the first bit of data out. You can read that post here.  In particular, we looked at two operators that could be used to ensure that a query returns only Distinct rows. and The Sort operator pulls in all the data, sorts it (discarding duplicates), and then pushes out the remaining rows. The Hash Match operator performs a Hashing function on each row as it comes in, and then looks to see if it’s created a Hash it’s seen before. If not, it pushes the row out. The Sort method is quicker, but has to wait until it’s gathered all the data before it can do the sort, and therefore blocks the data flow. But that was my last post. This one’s a bit different. This post is going to look at how Aggregate functions work, which ties nicely into this month’s T-SQL Tuesday. I’ve frequently explained about the fact that DISTINCT and GROUP BY are essentially the same function, although DISTINCT is the poorer cousin because you have less control over it, and you can’t apply aggregate functions. Just like the operators used for Distinct, there are different flavours of Aggregate operators – coming in blocking and non-blocking varieties. The example I like to use to explain this is a pile of playing cards. If I’m handed a pile of cards and asked to count how many cards there are in each suit, it’s going to help if the cards are already ordered. Suppose I’m playing a game of Bridge, I can easily glance at my hand and count how many there are in each suit, because I keep the pile of cards in order. Moving from left to right, I could tell you I have four Hearts in my hand, even before I’ve got to the end. By telling you that I have four Hearts as soon as I know, I demonstrate the principle of a non-blocking operation. This is known as a Stream Aggregate operation. It requires input which is sorted by whichever columns the grouping is on, and it will release a row as soon as the group changes – when I encounter a Spade, I know I don’t have any more Hearts in my hand. Alternatively, if the pile of cards are not sorted, I won’t know how many Hearts I have until I’ve looked through all the cards. In fact, to count them, I basically need to put them into little piles, and when I’ve finished making all those piles, I can count how many there are in each. Because I don’t know any of the final numbers until I’ve seen all the cards, this is blocking. This performs the aggregate function using a Hash Match. Observant readers will remember this from my Distinct example. You might remember that my earlier Hash Match operation – used for Distinct Flow – wasn’t blocking. But this one is. They’re essentially doing a similar operation, applying a Hash function to some data and seeing if the set of values have been seen before, but before, it needs more information than the mere existence of a new set of values, it needs to consider how many of them there are. A lot is dependent here on whether the data coming out of the source is sorted or not, and this is largely determined by the indexes that are being used. If you look in the Properties of an Index Scan, you’ll be able to see whether the order of the data is required by the plan. A property called Ordered will demonstrate this. In this particular example, the second plan is significantly faster, but is dependent on having ordered data. In fact, if I force a Stream Aggregate on unordered data (which I’m doing by telling it to use a different index), a Sort operation is needed, which makes my plan a lot slower. This is all very straight-forward stuff, and information that most people are fully aware of. I’m sure you’ve all read my good friend Paul White (@sql_kiwi)’s post on how the Query Optimizer chooses which type of aggregate function to apply. But let’s take a look at SQL Server Integration Services. SSIS gives us a Aggregate transformation for use in Data Flow Tasks, but it’s described as Blocking. The definitive article on Performance Tuning SSIS uses Sort and Aggregate as examples of Blocking Transformations. I’ve just shown you that Aggregate operations used by the Query Optimizer are not always blocking, but that the SSIS Aggregate component is an example of a blocking transformation. But is it always the case? After all, there are plenty of SSIS Performance Tuning talks out there that describe the value of sorted data in Data Flow Tasks, describing the IsSorted property that can be set through the Advanced Editor of your Source component. And so I set about testing the Aggregate transformation in SSIS, to prove for sure whether providing Sorted data would let the Aggregate transform behave like a Stream Aggregate. (Of course, I knew the answer already, but it helps to be able to demonstrate these things). A query that will produce a million rows in order was in order. Let me rephrase. I used a query which produced the numbers from 1 to 1000000, in a single field, ordered. The IsSorted flag was set on the source output, with the only column as SortKey 1. Performing an Aggregate function over this (counting the number of rows per distinct number) should produce an additional column with 1 in it. If this were being done in T-SQL, the ordered data would allow a Stream Aggregate to be used. In fact, if the Query Optimizer saw that the field had a Unique Index on it, it would be able to skip the Aggregate function completely, and just insert the value 1. This is a shortcut I wouldn’t be expecting from SSIS, but certainly the Stream behaviour would be nice. Unfortunately, it’s not the case. As you can see from the screenshots above, the data is pouring into the Aggregate function, and not being released until all million rows have been seen. It’s not doing a Stream Aggregate at all. This is expected behaviour. (I put that in bold, because I want you to realise this.) An SSIS transformation is a piece of code that runs. It’s a physical operation. When you write T-SQL and ask for an aggregation to be done, it’s a logical operation. The physical operation is either a Stream Aggregate or a Hash Match. In SSIS, you’re telling the system that you want a generic Aggregation, that will have to work with whatever data is passed in. I’m not saying that it wouldn’t be possible to make a sometimes-blocking aggregation component in SSIS. A Custom Component could be created which could detect whether the SortKeys columns of the input matched the Grouping columns of the Aggregation, and either call the blocking code or the non-blocking code as appropriate. One day I’ll make one of those, and publish it on my blog. I’ve done it before with a Script Component, but as Script components are single-use, I was able to handle the data knowing everything about my data flow already. As per my previous post – there are a lot of aspects in which tuning SSIS and tuning execution plans use similar concepts. In both situations, it really helps to have a feel for what’s going on behind the scenes. Considering whether an operation is blocking or not is extremely relevant to performance, and that it’s not always obvious from the surface. In a future post, I’ll show the impact of blocking v non-blocking and synchronous v asynchronous components in SSIS, using some of LobsterPot’s Script Components and Custom Components as examples. When I get that sorted, I’ll make a Stream Aggregate component available for download.

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