We have a few Percona Clusters setup 3 server node clusters with Percona 8.x Cluster and MySQL 8. If I wanted to use Commvault or some other backup utility, could I back 1 of the servers up in the cluster using that MySQL backup method? Or is there a special way I would have to go about it? Do I need to backup all 3? In addition to this, what is the best way to tell if all 3 nodes have the same data on them? What file is that Galera file or?
You only need to backup 1 MySQL server in a 3-node PXC as all 3 nodes should have the same data.
This is difficult as there is no built-in mechanism for this. Data integrity is really only checked between nodes when a write transaction takes place, and the integrity is only checked for the rows within the trx.
There is nothing in the protocol that checks every row on some sort of routine basis. Instead, check out pt-table-checksum which has support for PXC to validate all nodes have the same data.
Hey Matt thank you for this! Was just looking for some insight and you have provided that. Thank you!