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
