Normal operation

Nagios should accurately report that the cluster is operating normally. In case you would like additional verification, the following are manual diagnostics to be certain of normal operation.

On denoted systems {master, slaves}:

• master, slaves - # lsof -i | grep LISTEN | grep mysql shows mysqld listening on correct interface(s)
• master, slaves - mysql> show variables like 'read_only'; shows read_only is OFF for master and ON for slaves
• master, slaves - # mysqladmin status processlist shows a process on each host for replication
• master - mysql> show master status\G shows one returned line of output.
• slaves - mysql> show slave status\G shows one row of output with approximately 50 headers, including:

             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes 

• master - # pt-table-checksum --defaults-file=/etc/mysql/pt_checksum.cnf --replicate=percona.checksums --ignore-databases mysql --no-check-binlog-format
• master - # ls -l /var/log/mysql/binlog.* returns a list of files; binlog.index and the most recent file should all have been written very recently today.
• master, slaves - should be clean # ls -l  /var/log/mysql.err