How to pause Replication safely

MySQL & MariaDB Percona XtraDB Cluster 5.x
1

I need a way to temporary pause any replication events, such that any changes made on a node that’s been “paused” will eventually propagate through the cluster (assuming no conflicts are introduced in the mean time).

I have tried setting the wsrep_on variable to 0, however, this appears to ensure any changes are ignored entirely and no attempt is made to replicate these changes once wsrep_on is set to 1.

The difficult part of my requirement is that I need to be able to still connect to the server and perform various tasks (SELECT, UPDATE, INSERT, etc.) while replication is disabled, so simply shutting the server down is not an option.

I cannot seem to locate any useful information in the documentation. Any help would be appreciated.

Thanks!

2

This is simply not how Galera works, I’m afraid. Write availability with partition tolerance is not a trivial problem to solve.

Galera handles multi-node writing via synchronous replication which establishes global ordering. Global ordering is the only way to “merge” writes from multiple sources easily, but Galera nodes must be connected for this to work. It would be non-deterministic to re-merge hypothetical writes from a disconnected node into the global replication order of another portion of the cluster, hence Galera (and PXC) does not allow it.