thank you for your detailed reply.   sorry if i am digging this up, but i followed have a similar problem (topic partition 5 referencing a non-existent leader broker) and a replication factor of 1   i think this happened during a move of the topic from my colleagues.   anyhow i followed your instructions* and enabled the unclean leader election before restarting kafka as cloudera service via manager.   however, i am still receiving this line in the log of the supposedly new leader:   Broker xxx received LeaderAndIsrRequest with correlation id 1 from controller 1 epoch 1035 for partition [mytopic,5] but cannot become follower since the new leader [ID] is unavailable.  where ID is probably an old broker (i wouldnt know) but clearly not an active broker id (of which i have 3).   * with the exception that i did not generate a json file but wrote it myself, since only 1 partition needed id-correction and i entered the broker that already holds the partition data on disk ... View more