… need consistent performance. But dropping tables is known to cause stalls that exhibit themselves as reduced QPS during the table drops or stalls. Percona Server since version 5.1 has a feature know as “Lazy Drop Table…
Post: DROP TABLE and stalls: Lazy Drop Table in Percona Server and the new fixes in MySQL
June 22, 2012 By 33 Comments
Comment: DROP TABLE and stalls: Lazy Drop Table in Percona Server and the new fixes in MySQL
June 22, 2012 By 33 Comments
I think the most important metric is the max stall during DROP TABLE. Prior to getting any fixes from Oracle or Percona it … for my variation of the DROP TABLE improvement, I only measured throughput. I should have measured max stall duration too. Perhaps you can learn from my mistake. Without a fix our servers stall for ~1 second during DROP TABLE and…
Comment: DROP TABLE and stalls: Lazy Drop Table in Percona Server and the new fixes in MySQL
June 22, 2012 By 33 Comments
…This reduces the peak drop from 100% to 25%. Now consider ten pools, the maximum drop during a lock of …version of drop table relies on taking the buffer pool mutex and a mutex on the flush list, “Lazy Drop Table” … flush list mutex is still going to cause stalls.’ I find your reply to my question to …
Post: MySQL Backup tools used by Percona Remote DBA for MySQL
March 13, 2013 By 8 Comments
… data to be removed or overwritten A table (or entire schema) was dropped accidentally Your InnoDB table was corrupt and mysql shuts down… used Almost no locking, if not using myisam tables Built in compression Each table is dumped to a separate file. This is… a guardian process that runs during a backup. It then kills any process that causes a stall of the flush. We are…
Comment: MySQL Partitioning - can save you or kill you
June 28, 2012 By 45 Comments
… be a killer of INSERT rates on huge tables. His table is much larger than his RAM, so…out this operation; InnoDB periodically “stalls“.) In either engine, even without dropping the unused indexes, a 1-day… reasons. (1) DELETE via DROP PARTITION, and (2) no I/O thrashing during the inserts. He may …
Post: Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
…can be found here. Same as during last time I will provide my… mean there can be quite significant stall waiting for the page which is…used for these non-mysql processes drops rapidly when you increase the amount … like to keep tables small enough, “sharding” to many tables before they become so…
Post: Performance impact of complex queries
January 17, 2007 By 11 Comments
…queries which were taking milliseconds to stall for few seconds, especially in certain…happens. Disk Starvation As Cache efficiency drops more requests have to hit the… you use Innodb tables and so do not suffer from table locks reporting … to do something intense do it during the lowest load. Do not …
Post: Realtime stats to pay attention to in Percona XtraDB Cluster and Galera
November 26, 2012 By 4 Comments
…Seeing high values here may indicate you have nodes frequently dropping out and rejoining the cluster and you may …queue activity, and I find this is common except during cluster stalls. There are clearly a fair amount of … on the third. I had to decrease my table size from 250k to 2.5k to start …
