how to monitor mysql

Jorge Salamero Sanz <jsalamero@serverdensity.com>

29 October 2015

obviously ;-)

WhenProcess_count (/usr/sbin/mysqld)

!= 1alert

● Load● CPU● Memory● Swap● Network

● Read/Write requests● IO queue length● Average IO wait● Average R/W time● Read/Write bandwidth

Is MySQL available?

● Uptime● Threads_connected● Connection usage %● Aborted_connects

Typical points of failure:

● Errors in mysql.log● Are logs being rotated?● Deleted files with FD still open?● Enough disk space?

Are queries actually being run?

● Questions/s● Queries/s● Read/Writes● Commands

The bad queries (not necessarily):

● Slow_queries● Select_full_join● Created_tmp_disk_tables● Full table scans

Caches, buffers and locks:

● Innodb_row_lock_waits● Innodb_buffer_pool_wait_free● Open_tables● Long running transactions● Deadlocks

$ mysql$ mysqladmin$ innotop$ mysqlreport

Percona Monitoring Plugins

● Nagios, Cacti, Zabbix● can be used as CLI tools together

with Percona Toolkit

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