Finding out how far behind are the slaves using Seconds_Behind_Master

When managing a large number of MySQL slaves, often one needs to view a summarized list of the seconds by which the slaves are falling behind. Here is a small script that will allow you to do just that.

#!/usr/bin/bash
cat /list/slaves | while read i ; do echo $i; mysql -h $i -e "SHOW SLAVE STATUS \G" | grep "Seconds_Behind_Master" ; done

To use it create a list of slave hosts and place it in /list/slaves or wherever you like. Then create a script /scripts/slave_behind_all and paste the above code in it.