…MySQL Server 5.5.30, 5.6.11 and Percona Server 5.5.30 and check… below: # Overhead Samples Command Shared Object # …….. ………. ……. ………………. …_connections=5000 table_open_cache=5000 table-definition-cache…
Post: Troubleshooting MySQL Upgrade Performance Regressions
February 15, 2012 By Leave a Comment
… INDEXES FROM for tables involved and check cardinality) Different stats can often cause different plans. Run ANALYZE TABLE on both MySQL Versions to see… stats may cause old MySQL Version to get slower plan instead of new one getting faster. Check stats sampling settings such as innodb…
Post: How to Monitor MySQL with Percona's Nagios Plugins
February 22, 2012 By 11 Comments
…Sample problems include starting two instances of MySQL on the same files in the data directory, and refusing to shut down MySQL…check-mysql-replication-delay plugin checks for excessive delay, and pmp-check-mysql-replication-running checks…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…to the amazing MySQL manual, especially the option and variable reference table. But just …sample_pagesblogpercona.commanual innodb_status_fileblogpercona.commanual innodb_strict_modeblogpercona.commanual innodb_support_xablogpercona.commanual innodb_sync_spin_loopsblogpercona.commanual innodb_table…
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
… data from 1988 to 2010′; mysql> use ontime1; Database changed mysql> show table status like ‘ontime_fact’G …05-10 04:26:14 Update_time: NULL Check_time: NULL Collation: latin1_swedish_ci Checksum:… innodb-stats-on-metadata=0 innodb-stats-sample-pages=256 innodb-stats-update-need-lock…
Post: How to convert MySQL's SHOW PROFILES into a real profile
February 20, 2012 By 12 Comments
…list” included with the Sakila sample database to demonstrate: mysql> SET profiling=1; mysql> pager cat > /dev/null mysql> SELECT * FROM nicer_but_… | | checking permissions | 0.000802 | 0.46 | 6 | 0.0001336667 | | Creating tmp table | 0.000548 | 0.32 | 1 | 0.0005480000 | | Opening tables | …
Post: MySQL extensions for hosting
April 24, 2008 By 11 Comments
…SHOW TABLE_STATISTICS, SHOW INDEX_STATISTICS and SHOW USER_STATISTICS. The first two can interest anyone to periodically check …most traffic to help you with some strategic decisions. Sample outputs: mysql> SHOW USER_STATISTICS LIKE ‘hosting2′\G *************************** 1. row …
Post: The story of one MySQL Upgrade
October 8, 2010 By 8 Comments
…. Another table remained though. We used mk-table-sync –print as a diff tool for MySQL to see what is different in the tables… get sample read traffic from both master and slave. –sample=50 (or similar) option is important to check only limited number of samples for… from Percona Server 5.1 back to MySQL 5.0 and performed the same checks again – happily replication worked and there were…
Post: How much memory Innodb locks really take ?
July 13, 2006 By 11 Comments
… I used the same sample table as yesterday: CREATE TABLE `sample` ( `i` int(10)… DEFAULT CHARSET=utf8 mysql> show table status like “sample” \G; *************************** 1. row *************************** Name: sample Engine: InnoDB …:31:51 Update_time: NULL Check_time: NULL Collation: utf8_general…
Post: What to tune in MySQL Server after installation
September 29, 2006 By 118 Comments
…crash. table_cache – Opening tables can be expensive. For example MyISAM tables mark MYI header to mark table as … Values from 32M to 512M normally make sense. Check it however after a while and see if…can analyze workload. P.S Note MySQL distribution contains bunch of sample my.cnf files which may be…
