If you read Changes and Improvements in MariaDB 11.4 you might think there are no MariaDB Galera Cluster changes in this long-term series, maintained until May 2029, but this is far from the truth. There are a few things that you can totally benefit from in MariaDB Galera Cluster, and this series continues from Why MariaDB Galera Cluster 10.11?.

When one executes SHOW FULL PROCESSLIST, there is more information about the connection state now:

• waiting to execute in isolation – connection is executing DDL via wsrep_osu_method=TOI, operation is waiting for concurrent operations to finish first, so DDL is executed in isolation.
• waiting for TOI DDL – connection must wait for DDL statement to finish since another connection is executing a TOI.
• waiting for flow control – transactions paused due to flow control, connection is waiting for cluster to catch up. (consider this replication lag!)
• waiting for certification – connection is committing the transaction, but waiting for other cluster nodes to certify the transaction.

We also have a wsrep_status_file=galera_status.json variable for the my.cnf – this is a machine-readable JSON file to be used by monitoring tools, e.g. Galera Manager.

If you would like progress reporting for backups, don’t forget to set:

[mariadb]
wsrep_sst_method=mariabackup

[sst]
progress=1
rlimit=100m

In the above example, it is sent to the error.log (STDERR), but you can also set it to have a path. rlimit is to rate limit in bytes, and in this case it is m (megabytes). There is also k (kilobytes), g (gigabytes) and t (terabytes). Don’t forget that you are required to have pv on Linux for this to work.

There is also automatic SST user account management with Galera Cluster, so you never have to create an account for this; it is done internally for you.

Small, useful changes, and we have more in the pipeline, just that it has not been merged yet!

Don’t forget, we also have a MariaDB Galera Cluster webinar coming up on 19 February 2025!