Page History

...

Once the Zookeeper quorum is down, brokers could result in a bad state and could not normally serve client requests, etc. Although when Zookeeper quorum recovers, the Kafka brokers should be able to resume to normal state automatically, there are still a few corner cases the they cannot and a hard kill-and-recovery is required to bring it back to normal. Hence it is recommended to closely monitor your zookeeper cluster and provision it so that it is performant.

Also note that if Zookeeper was hard killed previously, upon restart it may not successfully load all the data and update their creation timestamp. To resolve this you can clean-up the data directory of the Zookeeper before restarting (if you have critical metadata such as consumer offsets you would need to export / import them before / after you cleanup the Zookeeper data and restart the server).

Why does controlled shutdown fail?

...