I am migrating to Amazon Web Services. I have a production site and associated mySQL Database, and I also have a staging site to try out changes prior to pushing to production.
In terms of AWS RDS, how do I manage these two databases? Should they both exist in the same instance, or should they each have their own instance?
My staging site does not have to be continuously available, does this change which option is best suited?
I think those databases should live in different instances. Production DB should definitely have its own instance. There are many reasons to that:
What happens if you have a bug in staging and you spam your instance with CPU-eating queries? If it is the same instance your production DB might be effected.
It is good to have instance monitoring only for production.
You will be able to set up configuration on the production instance that should not be set on staging such as multi-az availability.
You can stop the staging instance when ever you want and re-start it with just the data it had when you stopped it.
All in all, no reason to mix the two into the same instance. One for production, one for staging.
