Why Multi-AZ?

This morning a sales colleague asked me this question: why set up a multi-availability zone deployment, of 2 or even 3 sites?

I hesitated a bit, I mean in today’s world where CSPs are super reliable and having extremely high uptime and Service Level Agreements, we kind of forget that the downtime of an availability zone is still possible.

In this short article, I just want to list out the key reasons why set up a multi-AZ architecture.

1. High availability in case a major failure in an entire AZ (single point of failure sucks!)
2. No I/O delays during backups, as backups are taken from the standby instance
3. No interruptions to I/O when applying patches or performing upgrades for maintenance purposes
4. Increase in responsiveness when load balancing is used. If one AZ is constrained, the instances in other zones can digest the traffic.

Quick trivia, do you know that AWS have 7 times less downtime than the next biggest cloud services provider a.k.a Microsoft Azure?

Well that is all for today, have a great week ahead!