Daniel Urban created KAFKA-15372: ------------------------------------ Summary: MM2 rolling restart can drop configuration changes silently Key: KAFKA-15372 URL: https://issues.apache.org/jira/browse/KAFKA-15372 Project: Kafka Issue Type: Improvement Components: mirrormaker Reporter: Daniel Urban
When MM2 is restarted, it tries to update the Connector configuration in all flows. This is a one-time trial, and fails if the Connect worker is not the leader of the group. In a distributed setup and with a rolling restart, it is possible that for a specific flow, the Connect worker of the just restarted MM2 instance is not the leader, meaning that Connector configurations can get dropped. For example, assuming 2 MM2 instances, and one flow A->B: # MM2 instance 1 is restarted, the worker inside MM2 instance 2 becomes the leader of A->B Connect group. # MM2 instance 1 tries to update the Connector configurations, but fails (instance 2 has the leader, not instance 1) # MM2 instance 2 is restarted, leadership moves to worker in MM2 instance 1 # MM2 instance 2 tries to update the Connector configurations, but fails At this point, the configuration changes before the restart are never applied. Many times, this can also happen silently, without any indication. -- This message was sent by Atlassian Jira (v8.20.10#820010)