Monitoring and Taking Care of MySQL Replication

If you get your slave into production soon, your should make sure that you know how take care of it when something goes wrong. 

Knowing that the slave is stuck can monitored using open source tools like Nagios and its MySQL plugins. In general it is wise to have such a tool to monitor all your system and business aspect including the web server and login rates.

How do I know that my slave is stuck or not?

1. Connect to MySQL on the slave using permitted user.
2. Run the show slave status\G command.
3. The result should include the following lines with a Yes value. If any of them is No, there is a problem:

Slave_IO_Running: Yes
Slave_SQL_Running: Yes

It is stuck, What should I do?

1. Connect to the file system with a permitted user.
2. Check the values of the replication error log and take care according to it (tail -n 50 /var/lib/mysql/responder3.spd.co.il.err).

Bottom Line
Get into production!


Keep Performing,

Moshe Kaplan