Re:Immutable Infrastructure: No SSH
by axelfontaine on Monday July 13, 2015 @08:06AM
(#9877568)
"Availability Zones (AZs) are within a DC" => not really
See this Re:Invent 2014 talk about AWS Innovation At Scale http://mvdirona.com/jrh/talksandpapers/JamesHamiltonReInvent... => Slide 9: "Each AZ is 1 or more DC, No data center is in two AZs, Some AZs have as many as 6 DCs"
Sorry - you are right, with the scale of Amazon they are within a region. But that is still not Geo-Redundant. If a hurricane takes out Virgina, you are still going to loose your data.
AZ's are typically 5-15miles apart. Needs to be a pretty large hurricane that far in land to take out all the various datacenters.
Also, just to clarify, you can do multi-region RDS read-replicas for MySQL: https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_...
It is an multi-AZ DB, which is very different to multi-region. (Availability Zones (AZs) are within a DC, regions are separate DCs)