Are you upgrading your Kafka servers or your applications' client libraries? We upgraded our client libraries and then ran into an incompatibility when the upgraded client ran with an older broker cluster. But the issue was fixed by simply adding an ACL for IdempotentWrite on the brokers. This page was a very valuable explanation of this issue:
https://kpow.io/articles/kafka-producer-breaking-change/ -- Patrick Taylor Sr. Principal Software Engineer ptay...@snaplogic.com Mobile: 303-594-8979 Boulder, Colorado (US Mountain Time) <http://www.snaplogic.com/about-us/jobs> *SnapLogic Inc | 1825 South Grant Street | San Mateo CA | USA * This message is confidential. It may also be privileged or otherwise protected by work product immunity or other legal rules. If you have received it by mistake, please let us know by e-mail reply and delete it from your system; you may not copy this message or disclose its contents to anyone. The integrity and security of this message cannot be guaranteed on the Internet.