Github user markap14 commented on the issue: https://github.com/apache/nifi/pull/2445 @alopresto thanks, that's a great catch! I pushed a new commit that should address both of these issues. We were not properly shutting down the connections on the Processor was stopped. As a result, those Consumers were also not closed and so any prefetched messages were not rolled back. This caused you to also receive no more messages because the messages were all prefetched by the unclosed Consumers.