Hi @md1,
Couchbase and all SDKs can take a single IP address and discover all the other nodes within a cluster. So in XDCR when you enter in a single IP, we are using that to discover the cluster topology but we don’t use that as a funnel for replication. If a node fails, typically auto failover kicks in a fails over the node and XDCR will pick up intelligently from where it left off with the new cluster topology.
Hope that clears the confusion.
thanks
-cihan