Galera

Galera cluster to AWS Aurora migration & HA_ERR_FOUND_DUPP_KEY

In this post we will see a case study of a Galera Cluster migration to AWS Aurora and quick solution to the replication issue. A friend received an error in a Master-Master replication as follows: Could not execute Write_rows event on table _database._table; Duplicate entry ’65eJ8RmzASppBuQD2Iz73AAy8gPKIEmP-2018-08-03 08:30:03′ for key ‘PRIMARY’, Error_code: 1062; handler error HA_ERR_FOUND_DUPP_KEY; the event’s master log mysql-bin-changelog.000010, end_log_pos 1107814 We talked about it and I immediately started blabbering cons of writing on both masters, how to handle, roles of apps and so on. He intervened and revealed, it is Galera Cluster replicated to Aurora and he is...

MySQL to Galera Cluster Migration, Deadlock, Back to basics

This post is a lab experiment learning from migration to the Percona Xtradb Cluster (Galera) and a very unexpected DEADLOCK scenario which took me back to basics. (root@localhost) [test]>insert into app values (1); ERROR 1213 (40001): Deadlock found when trying to get lock; try restarting transaction Little background: We needed to work on migrating the standard MySQL replication to a Galera (Percona Xtradb Cluster). Previous configuration being one Master with two slaves detailed as follows: server-1: MySQL community 5.6 serving as Master server-2: MySQL community 5.6 serving as Slave server-3: MySQL community 5.6 serving as Slave We wanted to migrate...