I just noticed that all of our EC2 instances are in zone us-west-2b, but our Multi-AZ RDS instance is in us-west-2a.
Performance-wise everything seems to be okay, and it will be a hassle to "move" the instances to one place since you have to stop and re-create them all. However if either of the two zones goes down when we will have some downtime; if everything is in one zone then at least we have a higher chance of not being in the zone that has downtime...
Is this something worth fixing, or am I over-thinking it?
(I was about to purchase some EC2 Reserved Instances, which are tied to specific AZs, so I wanted to make sure before going through with it)
Thanks!
us-west-2a
right now, but that can change at any time. If the AZ it's in goes down, it's supposed to switch to another one automatically, so having your EC2s spread out should help with uptime rather than having them all go down ifus-west-2b
fails.