Migrating databases from One PXC environment to another

Question

We have two PXC environments, both in production. One of the PXC has three databases with not too much data though. Our plan to is to move these three databases to be part of the other PXC environment so we can remain with a single PXC environment in production. But during the moving process, there should not be any downtime. How can we go about achieving this?

One of the thoughts we had was doing a dump on these three databases, then have them restored on their new env via replication.

Any suggestion or solutions on how we can go about achieving this without any downtime?

Answer 1

"One of the PXC has three databases with not too much data though" -> How much data are we talking about? 10GB? 100GB? 1TB? More?

Trying to do a migration like this without downtime is admirable, but you have to wonder how bad a planned downtime is for your application. Will your clients run away when you schedule a couple hours of downtime in the middle of the night? Unless your a global service provider, you should have a window somewhere during the night, no?

There probably are solutions to migration this without downtime, but is that worth all the hours you'll have to put in to make this work? Don't take on the stress if it's not worth it.

Source: someone who did take on the stress for similar things, and no they were not worth it.