From the initial release, one of the biggest complaints I had about Group Replication is that it allowed “stale” reads and there was no way to prevent them or to even know that you read “stale” data. That was a huge limitation. Thankfully, Oracle released features to control the consistency levels, and it was exactly a year ago! I don’t know about you, but I personally was confused by naming it group_replication_consistency=’AFTER’ or ‘BEFORE’.
So now I want to try to make sense of it and share my understanding (even if it is one year later).
- 3 Node Percona Server for MySQL 8.0.18 running in …