Hi Omid, That is an interesting question.. This paragraph was written some time ago and we have not test ZK failure / resume since, and it is hard to tell if these cases still exist or not.
One thing we can do is to add different ZK quorum failure scenarios to the system test to have it covered over time. Could you file a JIRA? Guozhang On Tue, Feb 3, 2015 at 4:23 AM, Omid Aladini <omidalad...@gmail.com> wrote: > Hi, > > Reading the official FAQ, I bumped into this paragraph: > > 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. > > > What are the corner cases exactly? Any JIRA tickets to explore? How do the > corner cases relate to the ZooKeeper cluster being "performant" and > "closely monitored"? I'm specifically interested in the inevitable scenario > that the ZK leader exits / dies and the quorum goes down momentarily (due > to hardware failure, rolling restart, etc). > > Thanks, > Omid > -- -- Guozhang
