Percona Server 5.6.21+ and MySQL 5.7.8+ offer the super_read_only option that was first implemented in WebscaleSQL. Unlike read_only, this option prevents all users from running writes (even those with the SUPER privilege). Sure enough, this is a great feature, but what’s the relation with GTID? Read on!

TL;DR

Enabling super_read_only on all slaves when using GTID replication makes your topology far less sensitive to errant transactions. Failover is then easier and safer because creating errant transactions is much harder.

GTID replication is awesome…

For years, all MySQL DBAs in the world have been fighting with positioning when working with replication. Each time you move a slave from one master to another, you must be very careful to start …