… it’s time to take off the gloves. I claim that somewhere around of 99% of advice about tuning MySQL‘s key… ratio is a waste of time! The Oracle folks arrived at this conclusion a long time before the MySQL world started to come around… above to pass without controversy. But really, it’s time to stop with the bad advice about counter ratios. The sooner we…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 5 Comments
…you close connection MySQL can clean them up. Killing connections (or stopping related applications… Com_stmt_send_long_data to see whenever sending long data feature …: 16384 INDEX_LENGTH: 0 CREATE_TIME: NULL UPDATE_TIME: NULL *************************** 2. row *************************** SESSION_ID:…
Post: Recovering Linux software RAID, RAID5 Array
August 27, 2011 By 2 Comments
…with MySQL you might need to deal with RAID recovery every … for a chance to write instructions for recovery for long time and finally I had gotten the problems with my …, or drive being resynced) as missing: ReadyNAS1:/# mdadm –stop /dev/md2 mdadm: stopped /dev/md2 mdadm –verbose –create /dev/md2 …
Post: Multiple purge threads in Percona Server 5.1.56 and MySQL 5.6.2
May 3, 2011 By 13 Comments
…subsequent purge work is ensured by a long-running transaction with a REPEATABLE READ …penalize further TPS. MySQL 5.6.2 Results Now let’s test MySQL 5.6.2… 5.6.2 completely fail to stop the history list growth, but at …other hand, TPS does slightly drop with time in the second half of the experiments…
Post: Data mart or data warehouse?
July 15, 2010 By 14 Comments
… outside of summarized form often takes a very long time. Is there a particular schema design which lends… mart”. Maybe this is because they provide one stop shopping for all the information about the particular… it may be on MySQL, but it is definitely possibly to use MySQL as long as the right tools…
Post: How to Monitor MySQL with Percona's Nagios Plugins
February 22, 2012 By 11 Comments
…happen at inconvenient times. The pmp-check-mysql-file-privs plugin checks whether MySQL owns every file… getting stuck, has long-running transactions, or other problems. The pmp-check-mysql-innodb plugin …LOCK_open contention. Replication is delayed or stopped. Our plugins are structured to monitor …
Post: Actively monitoring replication connectivity with MySQL's heartbeat
December 29, 2011 By 2 Comments
… or high latency peaks were not detected for a long period of time or not detected at all. We needed an active… to setup with negligible overhead: mysql_slave > STOP SLAVE; mysql_slave > CHANGE MASTER TO MASTER_HEARTBEAT_PERIOD=1; mysql_slave > START SLAVE; MASTER_HEATBEAT… do I have? The heartbeat check period time and the number of beats received. mysql_slave > SHOW STATUS LIKE ‘%heartbeat%’; +—————————+——-+ | Variable_name…
Post: The case for getting rid of duplicate “sets”
May 17, 2011 By 2 Comments
…, of course. Did you stop to add up the number one 10 times, and then then ten times more? Of course not. You… DEFAULT CHARSET=latin1 | +——-+—————————————————————————————————–+ 1 row in set (0.00 sec) mysql> select count(*) from ex1; +———-+ | count(*) | +———-+ | 73027220 | +———-+ 1 row in set…, notice that it takes a long time to delete. There is no index on this table. mysql> delete from data where val=16…
Post: MySQL Backup tools used by Percona Remote DBA for MySQL
March 13, 2013 By 8 Comments
…pull binary logs in real time to another server using “mysqlbinlog … –read-from-remote-server –raw –stop-never” Useful to mirror the… of restores Strategies on retention dailies weeklies, long term backups Decompressing Percona XtraBackup for MySQL in parallel using all your resources available…
Post: Living with backups
November 6, 2008 By 28 Comments
… same block again. That happens for as long as it does not get flushed. MySQL obviously takes advantage of this functionality just… by the system in memory and kept there for a long time. Since memory access is way faster than any disk access… running a simple copy operation from MySQL data directory will result in a total disaster after MySQL stops responding to the incoming queries…
