How do you reset the GroupCoordinator's stored session timeout for a group before the session timeout actually expires?
We have an emergency situation where we need to reduce the session timeout for a consumer group. The old session timeout was 12 hours (a temp hack to get around another problem), and now we want to reduce it back to a few minutes. Some of the consumers had a hard failure while the session timeout was set to 12 hours, so the GroupCoordinator is waiting 12 hours for those consumers to time out... we are on kafka 0.10.0, so the background heartbeat does not exist and hard failures only discovered through expiration of the session timeout. Obviously we do not want to wait 12 hours for the session to timeout, so I'm trying to figure out how to "reset" the consumer group's session timeout. We tried stopping all the consumers, then shutting down the broker that was the group coordinator. I was hoping that forcing the GroupCoordinator to migrate to a new broker would reset the session timeout. But as best I can tell, that doesn't work, because when we lowered the session timeout and then started the consumers again, they are stuck on re-joining, far beyond their new session timeout. 1) Does anyone know for sure if shutting down the group coordinator while it thinks there are active consumers even though we've stopped them, will the existing session timeout be migrated to whichever broker becomes the new GroupCoordinator? 2) Is there any way to force the GroupCoordinator to clear the session timeout or are we stuck waiting out the 12 hours? (or migrating offsets to a new consumer group name and starting the consumers again under a new name) -- *Jeff Widman* jeffwidman.com <http://www.jeffwidman.com/> | 740-WIDMAN-J (943-6265) <><
