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Greg Harris commented on KAFKA-15372: ------------------------------------- Hi [~durban] Thanks for the bug report. Is this reproducible with 3.5.0 and `dedicated.mode.enable.internal.rest` set to `true`? This configuration was added in [https://cwiki.apache.org/confluence/display/KAFKA/KIP-710%3A+Full+support+for+distributed+mode+in+dedicated+MirrorMaker+2.0+clusters] . > 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 > Priority: Major > > 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)