Amazon RDS Pros/Cons of Multiple DBs per instance
- by Joe Flowers
I run two completely independent websites.  I am moving their MySQL databases to Amazon RDS. 
I'm not going to do Multi A/Z deployment - let's remove that variable from this question.
I'm not sure whether to create a single RDS instance with two databases, or two Amazon RDS instances with a single database.  Ignore cost for the sake of this question.  I will not hit the 1 TB data limit so let's ignore that.  However, it is extremely important that crashing one of the websites doesn't impact the other.  
Based on this document -
http://docs.amazonwebservices.com/AmazonRDS/latest/UserGuide/Concepts.DBInstance.html
I'm assuming that if I write terrible code that crashes one of the databases in a given RDS instance, it could possibly take down the entire RDS instance (and thus inadvertantly affect the other database).  Is that correct?
Thanks