Thank you for the response. Will follow the recommendation for the update. So with Read=LOCAL_QUORUM we should see some latency, but not failures during RF change right?
We do mitigate the issue of not seeing writes when set to Local_one, by having a Retry logic in the app ________________________________ From: Leena Ghatpande <lghatpa...@hotmail.com> Sent: Friday, May 22, 2020 11:51 AM To: cassandra cassandra <user@cassandra.apache.org> Subject: any risks with changing replication factor on live production cluster without downtime and service interruption? We are on Cassandra 3.7 and have a 12 node cluster , 2DC, with 6 nodes in each DC. RF=3 We have around 150M rows across tables. We are planning to add more nodes to the cluster, and thinking of changing the replication factor to 5 for each DC. Our application uses the below consistency level read-level: LOCAL_ONE write-level: LOCAL_QUORUM if we change the RF=5 on live cluster, and run full repairs, would we see read/write errors while data is being replicated? if so, This is not something that we can afford in production, so how would we avoid this?
