This blog we describe an issue with MySQL 5.7’s super_read_only feature when used alongside with GTID in chained slave instances.
Background
In MySQL 5.7.5 and onward introduced the gtid_executed table in the MySQL database to store every GTID. This allows slave instances to use the GTID feature regardless whether the binlog option is set or not. Here is […]
This blog post will discuss how to use the MySQL super_read_only system variable.
It is well known that replica servers in a master/slave configuration, to avoid breaking replication due to duplicate keys, missing rows or other similar issues, should not receive write queries. It’s a good practice to set
read_only=1 on slave servers to prevent any […]
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 […]
