If its IP address got changed, then you hit a known bug https://issues.apache.org/jira/browse/ZOOKEEPER-1506 and you need to bounce the cluster.
Thanks, Daniel -----Original Message----- From: Ian Spence <[email protected]> Sent: Thursday, January 24, 2019 2:36 PM To: [email protected] Subject: ZK Server does not join quorum after restart Hello We have a cluster of 5 ZK servers, all running ZK 3.4.6 on Java 1.8 on CentOS 6. These are physical devices, not virtual machines. One server required hardware maintenance, and was restarted. When the zk software was restarted, it did not rejoin the quorum as a follower. Running “stat” or “mntr” commands returns: “This ZooKeeper instance is not currently serving requests” I googled this message and came across this bug: https://urldefense.proofpoint.com/v2/url?u=https-3A__issues.apache.org_jira_browse_ZOOKEEPER-2D2164&d=DwIGaQ&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=JE3yjNS4hXa8nS9n2uFCwEqMvv18hzzEnqunUhCoEns&m=S_8TazqwUbEfRtAYQCn8kA7F2tiGUBaVr3c_nj0Fh8A&s=FGIs9YOjwdYrzBH8om70Jx11KemHKRDsMY_kZK6cpK0&e= Does anybody know if there is a work-around to this issue? We’ve seen this problem multiple times in the past and our current solution is to bring down the zk cluster (which is a huge outage-causing pain). Thanks - Ian
