May 19, 2013

How to start a Percona XtraDB Cluster

Before version 5.5.28 of Percona XtraDB Cluster, the easiest way was to join the cluster using wsrep_urls in [mysqld_safe] section of my.cnf. So with a cluster of 3 nodes like this : node1 = 192.168.1.1 node2 = 192.168.1.2 node3 = 192.168.1.3 we defined the setting like this :

With that line above in my.cnf [...]

Timezone and pt-table-checksum

I recently worked through an issue with a client trying to detect data drift across some servers that were located in different timezones.  Unfortunately, several of the tables had timestamp fields and were set to a default value of CURRENT_TIMESTAMP.  From the manual, here is how MySQL handles timezone locality with timestamp fields: Values for TIMESTAMP columns are [...]

Debugging sleeping connections with MySQL

Have you ever seen connection in the SHOW PROCESSLIST output which is in “Sleep” state for a long time and you have no idea why this would happen ? I see if frequently with web applications and it is often indication of trouble. Not only it means you may run out of MySQL connections quicker [...]