Removal of Async replication

WARNING: it is an internal article. Do NOT use it in production! Contact Canonical Data Platform team if you are interested in the topic.

Pre-requisits

Make sure both Rome and Lisbon Clusters are deployed using the Async Deployment manual!

Detach Cluster from ClusterSet

Note: It is important to switchover the Primary Cluster before detaching it from ClusterSet!

Assuming the Lisbon is a current Primary and we want to detach Rome (for removal or reuse):

juju remove-relation async-primary db2:async-replica

The command above will move cluster Rome into the detached state blocked keeping all the data in place.

Rejoin detached cluster into previous ClusterSet

At this stage, the detached/blocked cluster Rome can re-join the previous ClusterSet by restoring async integration/relation:

juju switch rome
juju integrate async-primary db1:async-replica

Removing detached cluster

Remove no-longer necessary Cluster Rome (and destroy storage if Rome data is no longer necessary):

juju remove-application db1 # --destroy-storage

New ClusterSet from detached Cluster

Convert Rome to the new ClusterSet keeping the current data in use:

juju run -m rome db1/leader recreate-cluster