- When users upgrade an existing MM2 cluster they don’t need to change any of their current configuration If they are using the default
replication.policy.separatoras this proposal maintains the default behaviour for MM2 with the default configs.
- If users users upgrade an existing MM2 to 3.1.x, 3.2.x, 3.3.x, 3.4.x, or 3.5.x and they are using a customised
replication.policy.separatorthey need to provide a new version of `
DefaulReplicationPolicy` that override `ReplicationPolicy.offsetSyncsTopic`and `ReplicationPolicy.checkpointsTopic` methods
ReplicationPolicy(which can optionally subclass the
DefaultReplicationPolicyclass) that overrides the
ReplicationPolicy.checkpointsTopicmethods to use old topics if they still want to use the old internal topics. Related JIRA to this is discussed in KAFKA-15102.
1- Add new interface for internal policies, the reason to reject is to minimise the number of MM2 customised classes