Recovery of Async replication
Pre-requisits
Make sure both Rome and Lisbon Clusters are deployed using the Async Deployment manual!
Recovery detached cluster
If relation between clusters was removed and one side went into detached/blocked state: simply relate async replication back to restore ClusterSet.
Recovery lost cluster
If a Cluster has been lost and the ClusterSet need new member: deploy new db application and init async replication. The data will be copied automatically and the new Cluster will join ClusterSet.
Recovery invalidated cluster
A cluster in the cluster-set gets invalidated when async replication auto-recovery fails on a disconnection event or when a failover is run against another cluster-set member while this cluster is unreachable. If the invalidated cluster connections is restored, it’s status will be displayed in juju status as:
App Version Status Scale Charm Channel Rev Address Exposed Message
db2 8.0.36-0ubuntu0.22.04.1 active 3 mysql 8.0/edge 234 10.152.183.241 no
Unit Workload Agent Address Ports Message
db2/0 active idle 10.1.124.208
db2/1* active idle 10.1.124.203 Primary (standby, invalidated)
db2/2 active idle 10.1.124.200
Which indicates that connectivity is possible, but replication channel is stopped. To restore replication operation, run:
juju run db2/leader rejoin-cluster cluster-name=rome
Being rome the name of the invalidated cluster.