Understanding Local_Quorum

Question

We have a 3 DC\'s[US,EU,ASIA] with 3 nodes each, so totally 9 nodes.We are experimenting anyways, so we can increment if we need to.

We are planning to use a RF of 2 pe

Answer 1

Quorum as you mentioned is majority (1/2 + 1). In the case of RF=2, majority is 1+1=2. That means you need 2 acknowledgements from your replica nodes in order for the request to be successful. Thus, if one of your two replicas goes down, you cannot achieve consistency and the request will fail.

To be able to handle an outage and still do quorum, I suggest upping replication factor to 3.