Upgrading with XDCR

When XDCR (Cross Data Center Replication) is implemented, the upgrade process depends on the XDCR scenario.

The xmem replication mode performs replication on a destination cluster with the memcached protocol. This is the default mode for Couchbase Server replications. The capi mode performs replications over a REST protocol.

  • xmem - only Couchbase Servers 2.2 and later support it.
  • capi - both Couchbase Servers 2.2 and earlier support it.

The following prerequisites need to be considered:

  • Network port 11210 needs to be open between nodes for xmem mode of replication to work.
  • In general, delete the replication, complete the upgrade, then recreate the replication.
  • When upgrading Couchbase Server, make sure that both the source and destination clusters support the desired replication mode.
  • To use XDCR data encryption with Secure Socket Layer (SSL), all nodes must be upgraded to at least Couchbase Server 2.5 Enterprise Edition.

Upgrade scenarios

Both source and destination clusters are pre-2.2 and both are upgrading to pre-2.2 versions.
This scenario is supported since both clusters use capi.
Both source and destination clusters are pre-2.2 and the destination is upgrading to 2.2.
This is a safe upgrade path since the source cluster communicates via capi to the destination cluster.
The source cluster is upgrading to 2.2 or later and the destination is pre-2.2.
This is a safe upgrade path because the source cluster can communicate via capi or xmem to the destination cluster.
Both source and destination clusters are upgrading from pre-2.2 to 2.2.
This is a safe upgrade because the XDCR protocol remains the same (capi).
The source cluster is upgrading from pre–2.2 to 2.2 or later and the destination cluster is Elasticsearch.
Since the source cluster must use capi for replication:
  1. Delete all XDCR replications on your source cluster.
  2. Upgrade the source cluster to 2.2 or later.
  3. Re-create the XDCR replications using Version 1 for the XDCR protocol. Version 1 is capi replication.
Both source and destination clusters are upgraded from pre-2.2 to 2.5 or later.
This is not a safe upgrade path because the cluster upgrades are not synchronized. If the source upgrade completes prior to destination upgrade, incorrect data replication and failures in conflict resolution can occur.
  1. Delete all XDCR replications on your source cluster.
  2. Upgrade the source cluster to 2.5 or later.
  3. Upgrade the destination cluster to 2.5 or later.
  4. Re-create the XDCR replications using Version 2 for the XDCR protocol. Version 2 is xmem replication.