Hi All, in a recent PR I try to fix an issue we found with Suhas Dantkale in ZOOKEEPER-2146 (see https://github.com/apache/zookeeper/pull/1254). The problem is that in ZooKeeper 3.5+ some quorum members can not rejoin to the quorum after a restart if the server configs are set like this:
zoo.cfg in server 1: server.1=0.0.0.0:2888:3888 server.2=some.fqdn-2.com:2888:3888 server.3=some.fqdn-3.com:2888:3888 zoo.cfg in server 2: server.1=some.fqdn-1.com:2888:3888 server.2=0.0.0.0:2888:3888 server.3=some.fqdn-3.com:2888:3888 I am not exactly sure about the use case behind this config, but people claim they need it for specific dockerized environments (see the comments in the jira ticket). Is anyone familiar with such use cases? We never used such configs in production as far as I can tell. The above config worked without a problem in ZooKeeper 3.4.x, but not perfectly for 3.5.x. It would be logical to keep supporting it. Still, I think after the introduction of the dynamic reconfig, we kind of assume that all the servers have the same server address configurations. So maybe the config is not even valid anymore? Using the 'quorumListenOnAllIPs' config property instead the 0.0.0.0 in the configs might solve the issue. But if it is the case, then we definitely should highlight this in the wiki / documentation. Maybe even printing out a warning during ZooKeeper startup. What do you think? Kind regards, Mate
