…MySQL replication is asynchronous. What about semi-sync MySQL replication? It’s actually much worse than Galera. As I illustrated in a…in the local apply queue on their nodes will get a deadlock…
Post: Understanding Multi-node writing conflict metrics in Percona XtraDB Cluster and Galera
November 20, 2012 By 17 Comments
…-node writing causes unexpected deadlocks in PXC, at least, it is unexpected unless you know how Galera replication works. This is a complicated topic… the: Total number of local transactions that failed certification test. What is a local certification test? It’s quite simple: On COMMIT…
Post: How to Monitor MySQL with Percona's Nagios Plugins
February 22, 2012 By 11 Comments
… papers, you’ll see a pretty extensive list of suggestions for what to monitor in MySQL. Those are only suggestions; …deadlocks. Deadlocks (and lock wait timeouts, covered in another plugin) are frequent causes of serious errors in applications because the applications often don’t handle deadlocks…
Post: Logging Foreign Key errors
September 27, 2012 By Leave a Comment
…in order to have historical data. pt-fk-error-logger This is a tool very similar to pt-deadlock… to know what the problem is. 4- Let’s check what the tool has logged: mysql> select * …causes the error was: mysql> ALTER TABLE employees DROP PRIMARY KEY; Conclusion If you are having too many deadlock…
Post: A quest for the full InnoDB status
October 31, 2008 By 4 Comments
…in very long execution times for even simplest queries, or a huge deadlock. In…in MySQL data directory. Unfortunately this is a startup time parameter, so unless you set it early, it will not be available in…what MySQL…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… kinds of other things. In MySQL 5 number of Innodb performance counters were exported and now available in SHOW STATUS output. …a ;; *** WE ROLL BACK TRANSACTION (2) For last deadlock Innodb shows transactions which caused deadlocks, their state during deadlock, what locks they were holding and what…
Post: Test Drive of Solid
September 22, 2006 By 5 Comments
…a deadlock. Test 2: SELECT FOR UPDATE: mysql> begin; Query OK, 0 rows affected (0.00 sec) mysql…what we’ll see in final version. Current behavior is however very different from Innodb in…
Post: Announcing Percona XtraBackup 2.0.5
January 23, 2013 By Leave a Comment
…. This option specifies from what extra file to read the default MySQL options before the standard defaults… or stream in very small chunks which in return caused inefficient I/O. Fixed by using a 1M …t re-remove the suspend file, leading to a wait deadlock. Fixed by removing the stale xtrabackup_…
