We currently have more or less the following setup:
- Three individual MySQL database servers (individual Linux machines) with 15 to 50 logical databases and 20 to 50 GB of data
- Galera cluster (MariaDB) with 3 nodes and ~5 logical databases and currently around 10GB of data
- Load balancer for Galera cluster (Haproxy)
Our plan is to migrate the individual database servers to the cluster, i.e. move all data from the individual servers to the cluster.
What would be to best way to do this so that there is:
- No downtime for cluster users (individual node of course can be down since it does not cause downtime for the entire cluster)
- Minimal (or no) downtime for the individual servers
All the servers are in the same datacenter, so data moves quite quickly between the servers. However there is quite a lot of data to be moved...
Any ideas?