Couchbase in AWS with replicas and server groups per AZ


#1

We have a “Best Practices” question around how the latest version of Couchbase behaves with respect to AWS availability zones.

If we deploy a single couchbase cluster (9 nodes) across 3 availability zones in AWS where each AZ has it’s own Couchbase server group defined. What happens if we lose an entire availability zone in AWS (~ 3 nodes) assuming we have just 1 replica?

Are we safe to perform a rebalance of the last remaining 6 nodes because of the “Server Group” functionality which should guarantee that all the replicas exist in one of the other availability zones?


#2

@bryan,

Yes, that is my understanding of how rack zone awareness (i.e. Couchbase node groups) works - https://developer.couchbase.com/documentation/server/5.0/architecture/cluster-manager.html#concept_ydh_lmj_vs__RZA