Hey Abraham, We've been using 3.4.11.
That's great news the reverse lookup has already been taken out in 3.5! We found another ticket https://issues.apache.org/jira/browse/ZOOKEEPER-2858 that suggested there were some workarounds but hadn't found that one (and hadn't had a chance to test 3.5). This raises an interesting question for us, admitted ZK neophytes, is ZK 3.5 "safe" to use in production? On Fri, Nov 17, 2017 at 3:11 PM, Abraham Fine <[email protected]> wrote: > This change occurred due to > https://issues.apache.org/jira/browse/ZOOKEEPER-2171 > > On Fri, Nov 17, 2017, at 15:10, Abraham Fine wrote: > > Hi Ben- > > > > What version of ZooKeeper are you using? In my testing it looks like 3.4 > > does a reverse lookup when creating the server principal > > (https://github.com/apache/zookeeper/blob/branch-3.4/src/ > java/main/org/apache/zookeeper/ClientCnxn.java#L1011) > > but 3.5/master do not > > (https://github.com/apache/zookeeper/blob/branch-3.5/src/ > java/main/org/apache/zookeeper/ClientCnxn.java#L1104). > > > > Let me know if that helps. > > > > Thanks, > > Abe > > > > On Fri, Nov 17, 2017, at 12:01, Ben Wood wrote: > > > Hey Folks, > > > > > > My team and I are working on a containerized Zookeeper service on top > of > > > DC/OS. We're running into an issue with Kerberos in the following > > > scenario. > > > > > > Simplified, we have a zk server with the DNS address zk-server.dcos > (e.g. > > > the dns address of the ZK task) and actual hostname zk-server.aws > > > (Shortened here, but really a standard resolvable AWS private dns > > > address) > > > and a kafka broker, kafka.dcos. > > > > > > We can easily setup our Zookeeper and Kafka services to work together, > > > until we try to enable Kerberos. ZK itself works just fine with > Kerberos, > > > but the Kafka broker is not able to connect to the ZK server: > > > > > > 0. kafka.dcos is started with a zk server list of zk-server.dcos. > > > 1. kafka.dcos starts up, initializing its ZK client. > > > 2. kafka.dcos then attempts to retrieve a ticket from the KDC in order > to > > > talk to zk-server.aws, however the only zk principal known to the kdc > is > > > zk-server.dcos. > > > > > > From reading the source ( > > > https://github.com/apache/zookeeper/blob/master/src/ > java/main/org/apache/zookeeper/client/StaticHostProvider.java#L112) > > > it appears that the zk client is winding up with the actual hostname of > > > the > > > ZK server. > > > > > > Being new to the codebase, is this because of a client reverse lookup? > Or > > > because the zk server is telling the client about its hostname? It > > > appears > > > to be the former. > > > > > > Thanks! > > > Ben > -- Ben Wood Software Engineer - Data Agility Mesosphere
