I was recently struck by a problem which is unusual. In order to keep an eye on the database server I use nagios, cacti, merlin (http://www.mysql.com/products/enterprise/monitor.html" target="_blank) and some local scripts to monitor the database instance and ensure that it is working properly. That normally works fine. The different monitor processes do various things, one of which is to monitor the replication status of a slave, and warn me if the replication is not working or if it’s behind. This is done with the command
SHOW SLAVE STATUS.
The server I was looking at runs some large local batch jobs aggregating data. Unfortunately, I was experiencing that replication was interfering with these batch jobs so decided to see if things would perform better if[Read more...]