Please check out Backward Compatibility section in https://cwiki.apache.org/confluence/display/ZOOKEEPER/ReleaseManagement.
A few other comments inline. On Tue, May 22, 2018 at 2:47 PM, Shawn Heisey <apa...@elyograg.org> wrote: > Somebody on the solr-user mailing list has posed a question about > whether they can use ZK 3.4.12 on the server side and a specific version > of Solr on the client side. The specific version of Solr they're asking > about includes ZK 3.4.10 for its client code. > > I would not anticipate any issues running with 3.4.10 on the client side > and 3.4.12 on the server side, so I think I can safely answer their > question, but I have a more general question to ask. > > Are there ANY mixed version matchups that present problems, assuming the > server is running a newer version than the client? I would never advise > running a server version that's older than the client. > If the mixed versions are not compatible (see the reference in the link), there might be problems. > > The very first release of Solr to feature ZK integration was 4.0-ALPHA, > and eventually the stable 4.0.0 release, which included ZK 3.3.6. The > subsequent version of Solr, which was 4.1.0, included ZK 3.4.5. We > expect to include ZK 3.4.12 with the next release of Solr - 7.4.0. > > I did a simple test with Solr 4.0.0 against a single ZK 3.4.12 server. > It started just fine. The testing was not exhaustive, but I saw zero > problems. > > What I intend to say on the solr-user thread is that ZK 3.4.12 can be > used with ALL SolrCloud versions, but I thought I should sanity-check > that statement here before I make it. > ZK 3.4.x is compatible with ZK 3.3.y releases (major.minor is compatible with major.(minor-1)), so in your case this statement should be true. > Thanks, > Shawn > >
