Yeah, 3.4.x upgrades were pretty strainght-forward. The 3.5.5 upgrade was trickier, but the problems were in the admin UI. The admin UI uses several “4 letter words” to do its ZooKeeper reporting, and that required explicit permissions, but IIRC that all only affected the admin UI reporting about Zookeeper. There were a _lot_ of Solr changes, but that was mostly cosmetic and mostly in the test code.
Best, Erick > On Feb 13, 2020, at 4:07 PM, Rahul Goswami <rahul196...@gmail.com> wrote: > > Thanks Eric. Also, thanks for that little pointer about the JIRA. Just to > make sure I also checked for the upgrade JIRAs for other two intermediate > Zookeeper versions 3.4.11 and 3.4.13 between Solr 7.2.1 and Solr 7.7.2 and > they didn't seem to contain any Solr code changes either. > > On Thu, Feb 13, 2020 at 9:26 AM Erick Erickson <erickerick...@gmail.com> > wrote: > >> That should be OK. There were no code changes necessary for that upgrade. >> see SOLR-13363 >> >>> On Feb 12, 2020, at 5:34 PM, Rahul Goswami <rahul196...@gmail.com> >> wrote: >>> >>> Hello, >>> We are running a SolrCloud (7.2.1) cluster and upgrading to Solr 7.7.2. >> We >>> run a separate multi node zookeeper ensemble which currently runs >>> Zookeeper 3.4.10. >>> Is it also required to upgrade Zookeeper (to 3.4.14 as per change.txt >> for >>> Solr 7.7.2) along with Solr ? >>> >>> I tried a few basic updates requests for a 2 node SolrCloud cluster with >>> the older (3.4.10) zookeeper and it seemed to work fine. But just want to >>> know if there are any caveats I should be aware of. >>> >>> Thanks, >>> Rahul >> >>