Various Questions


#1

Hi folks, I’m trying to verify my understanding of couchbase and have a few questions.

Questions:

  1. When A Document is written to a node, (it will be replicated async to n or more nodes configured within the ‘bucket definition’)
    so…if the number of replicas is set to 1, then in the SDK (Java) if you specify replicateTo.ONE, the future will report done only after it has replicated to 1 ‘local’ node? correct?

  2. If XDCR is enabled, does the ReplicateTo function imply (local replication, or xdcr replication or both??)…ie. is there a way to verify the document as been replicated cross dc?
    in the XDR case if the bucket is listed with 1 replica, would we specifying ReplicateTo.TWO verify it was copied to the remote DC as well?

  3. If a node with a document goes offline, another node with the document is ‘promoted’ to active, I assume this means that node can accept writes to that document as well?

  4. If (all nodes) with document A go offline in a cluster, and that ‘cluster’ receives a read/write request, will the request be forwarded to other cluster? (assuming XDCR is in play) or does it simply fail? i.e. do the clusters delegate requests to other clusters if for some reason it cannot service the request locally?

  5. Reading up on replication, it indicated replication only occurs after the data has been persisted (at least in the XDCR docs)…what if the bucket type is memcached? which has no persistence? Is XDCR not supported on membached buckets?

Thanks
Dan