I'm curious to hear what others think about this as well. I run some WordPress sites in containers and I give each one it's own DB instance. I just create the root account with a strong password, give it to WordPress and call it a day. Makes ops much simpler although it's probably not the best use of resources (e.g. memory).
Any big downsides to doing things this way? I'm no DBA so I appreciate any insights.
It may be more cost effective to use the same db instance, but that has it's own issues, like 1 site dragging everyone down, all sites need to handle the same db version and upgrade together..
I guess it's also just more instances to manage in total, instead of 1 + n it's 2n.
You _could_ run the dbs on the same instance but not using the same DB process, via containerisation perhaps. That way you could reduce your instance count while still keeping (somewhat) operational separation..
Scaling, durability and backup. Your single small container DB may not be able to serve high requests per second. It depends on the architecture and caching, though. If it goes down, your app goes down, no failover or replicas. And it is difficult to backup many isolated DB instances.
Any big downsides to doing things this way? I'm no DBA so I appreciate any insights.