if replication factor is 1. we have 2 nodes. if one node goes down. other node data will become active. But what about replication. Since its set to 1 with one node running,should not it give error that replication set to 1 but no other node to replicate. what will happen in this case can some one explain me in detail. will the other node which is running will also come down or nothing will happen until we add the node back again. I am talking in terms of replication.
When you have auto-failover turned on, and a node fails, then the replica documents on other nodes will become active. However, with fewer than 2 nodes, auto-failover is disabled.
If you don’t have enough nodes to support the configured replication, you will see an error message on the Couchbase Web Console. Something like “Fail Over Warning: At least two servers with the data service are required to provide replication!” You can also setup Alerts to receive email notification when various fail-over events occur.
You can read more about alerts here: https://developer.couchbase.com/documentation/server/current/settings/configure-alerts.html
You can read more about Intra-cluster Replication here: https://developer.couchbase.com/documentation/server/current/architecture/high-availability-replication-architecture.html