The documentation does not say that Solr uses the zk client 3.4.11. It says, "Solr currently uses Apache ZooKeeper v3.4.11.” That is on the page titled "Setting Up an External ZooKeeper Ensemble” in the section "Download Apache ZooKeeper”. Maybe that is supposed to mean “The Solr code uses the 3.4.11 client, use whatever server you want”, but I read that as a recommendation to use the 3.4.11 server.
http://lucene.apache.org/solr/guide/7_4/setting-up-an-external-zookeeper-ensemble.html#download-apache-zookeeper wunder Walter Underwood wun...@wunderwood.org http://observer.wunderwood.org/ (my blog) > On Jun 29, 2018, at 11:54 AM, Zimmermann, Thomas <tzimmerm...@techtarget.com> > wrote: > > Thanks Shawn - I misspoke when I said recommendation, should have said > ³packaged with². I appreciate the feedback and the quick updates to the > Jira issue. We¹ll plan to proceed with 3.4.12 when we go live. > > -TZ > > On 6/29/18, 11:38 AM, "Shawn Heisey" <apa...@elyograg.org> wrote: > >> On 6/28/2018 8:39 PM, Zimmermann, Thomas wrote: >>> I was wondering if there was a reason Solr 7.4 is still recommending ZK >>> 3.4.11 as the major version in the official changelog vs shipping with >>> 3.4.12 despite the known regression in 3.4.11. Are there any known >>> issues with running 7.4 alongside ZK 3.4.12. We are beginning a major >>> Solr upgrade project (4.10 to 7.4) and want to stand up the most recent >>> supported versions of both ZK/Solr as part of the process. >> >> That is NOT a recommendation. >> >> The mention of ZK 3.4.11 in Solr's CHANGES.txt file is simply the >> version of ZK that Solr ships with. ZK is included with Solr mostly for >> the client functionality. The regression is in the server code, and >> unless you run the embedded ZK server, which is not recommended for >> production, the ZK library that ships with Solr will not experience the >> regression. >> >> I am not aware of anywhere in Solr or its reference guide that makes a >> recommendation about a specific version of ZK. The reference guide does >> mention version 3.4.11, but that's only because that's the version that >> Solr includes. The version number in the documentation source code is >> dynamic and will always match the specific version that Solr includes. >> >> The compatibility goals of the ZK project indicate that you can run any >> 3.4.x or 3.5.x version of ZK on the server side and be compatible with >> the ZK 3.4.x client that's in Solr. >> >> Look for "Backward Compatibility" on this page: >> >> https://cwiki.apache.org/confluence/display/ZOOKEEPER/ReleaseManagement >> >> We have an issue for upgrading the version of ZK in Solr to 3.4.12. I >> have uploaded a new patch on that issue to try and clear up any >> confusion about what version of ZK is recommended for use with Solr: >> >> https://issues.apache.org/jira/browse/SOLR-12346 >> >> Thanks, >> Shawn >> >
