… mode); same MySQL queries executed inside …threads) Cisco UCS C250 (12cores/24 cpu threads) Dell PowerEdge R720 (16 cores/32 cpu threads…the mix, limitations of read…time=120 –max-requests=0 –percentile=99 –mysql-user=root –mysql-db=sbtest8t1M –mysql-table-engine=INNODB –mysql-socket=/tmp/mysql…
Post: Replication in MySQL 5.6: GTIDs benefits and limitations - Part 1
May 21, 2013 By 8 Comments
…. However you should keep in mind some limitations of the current implementation. This post is …time, replication on slave #1 will stop: 2013-05-17 13:32:08 2563 [ERROR] Slave I/O: The slave IO thread…the master: mysql> create table test.t (id int not null auto_increment primary key); Executing SHOW …
Post: Galera Flow Control in Percona XtraDB Cluster for MySQL
May 2, 2013 By 5 Comments
…cluster might be: mysql> set global wsrep_provider_options=”gcs.fc_limit=500; … transaction briefly stalling an applier thread. However, it is possible to … conflicts more likely and therefore time-consuming to the application. How …easily see flow control if I execute a FLUSH TABLES WITH READ LOCK …
Post: High-load problems? Investigate them with 'pt-query-digest'
April 23, 2013 By 2 Comments
…stalk to trigger a capture if Threads_running went above a known ‘…, or if there was another limiting factor in the workload that … up having a much better execution plan, but that is beyond…time without issues. If you regularly work with MySQL databases, getting familiar with Percona Toolkit for MySQL…
Post: Evaluating IO subsystem performance for MySQL Needs
March 5, 2008 By 23 Comments
… system. What I usually look for MySQL is performance in random reads and … I/O mode Doing random read test Threads started! Time limit exceeded, exiting… Done. Operations performed: 773835…percentile: 0.0001s Threads fairness: events (avg/stddev): 773835.0000/0.00 execution time (avg/stddev): …
Post: Virtualization and IO Modes = Extra Complexity
March 21, 2011 By 12 Comments
….06ms Threads fairness: events (avg/stddev): 1343.0000/0.00 execution time (avg/stddev): 0.0808/0.00 Ignore response times here as it times…, Enabled. Using synchronous I/O mode Doing random write test Threads started! Time limit exceeded, exiting… Done. Operations performed: 0 Read, 33900 Write…
Post: How to debug long-running transactions in MySQL
March 8, 2011 By 6 Comments
… query the tables, and if something is blocked, find its thread ID. Match this up with the ID in SHOW PROCESSLIST… INNER JOIN information_schema.processlist p on b.trx_mysql_thread_id = p.ID LIMIT 1′) if [ "${host}" ]; then echo “Host ${host} is… times. Alas, there are some cases where it won’t work. If the offending transaction is idle, and not continuing to execute…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…execute…thread_handlingblogpercona.commanual thread_stackblogpercona.commanual Threads_cachedblogpercona.commanual Threads_connectedblogpercona.commanual Threads_createdblogpercona.commanual Threads_runningblogpercona.commanual time_formatblogpercona.commanual time_zoneblogpercona.commanual timed…
Post: Can't Create Thread: Errno 11 (A Tale of Two Ulimits)
February 4, 2013 By 12 Comments
…boot time by SysV initscripts are not affected by changes to these limits files.[…thread limit: (root@revolution 23:59:37)# service mysql restart Shutting down MySQL (Percona Server)… SUCCESS! Starting MySQL…”service mysql restart” is executed from a session that has picked up the modified limits. […
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
… @ localhost [] # Thread_id: 1 Schema: test Last_errno: 0 Killed: 0 # Query_time: 0.117904 Lock_time: 0…. such as the total query execution time and the average query execution time, the number of tmp tables … query execution plan used by MySQL. The end result might be that you end up limiting the …
