Solrj 4.x will not work with collections created from Solr 5.0 but otherwise I am not aware of any incompatibility between 4.x and 5. There was a compat break in Solrj during 4.8 I think but it was due to a bug. The standard advise on upgrading is to upgrade the client first and then the server. Solrj 5.0 will work fine with Solr 4.x.
On Fri, Mar 27, 2015 at 6:26 AM, Karl Wright <daddy...@gmail.com> wrote: > Thanks, Shawn. > > We strive to be sure that the underlying dependencies of SolrJ are all the > correct versions. So my question revolved more around any known > dependencies between SolrJ and specific Solr API elements. We understand > that Solr Cloud moves quickly and we try to keep up by updating SolrJ. It > would be good to know that efforts were being made to assure backwards > compatibility so that a newer Solr Cloud would at least work properly > against an older Solr instance. > > If that cannot be assured, then it seems to me like the current > architecture needs revision in some way. Clients really aren't able to > re-release code on the same schedule as Lucene, and cannot be expected to > support multiple SolrJ libraries simultaneously. > > Karl > > > On Fri, Mar 27, 2015 at 9:10 AM, Shawn Heisey <apa...@elyograg.org> wrote: > >> On 3/27/2015 2:29 AM, Karl Wright wrote: >> > Now that Solr 5.0.0 has been released, the ManifoldCF project needs to >> > figure out the appropriate time to upgrade to a newer SolrJ. Can anyone >> > point me at the backwards-compatibility policy for SolrJ 5.0.0? Will it >> > work properly with Solr 4.x? >> >> We do strive for compatibility, but sometimes there is breakage, in >> order to achieve progress. >> >> If you are NOT running SolrCloud, compatibility between wildly different >> versions of Solr and SolrJ should be excellent. For my non-cloud >> install, I am using SolrJ 5.0.0 with Solr 4.7.2 and 4.9.1 with no >> problems. >> >> If you try to mix a 3.x version with a 4.x or 5.x version, or a 1.x >> version with anything later, changes in the typical client coding >> methods will probably be required, but it is extremely likely that it >> will be possible to make it work. >> >> SolrCloud is where the difficulty comes in. SolrCloud is evolving at an >> extremely rapid pace, and the coupling between SolrJ and the SolrCloud >> API (zookeeper in particular) is *extremely* tight. >> >> For the most part, if you are running a newer CloudSolrClient version >> than the server, things should work ... but for best results, I would >> not allow the version spread to get very wide, preferably not more than >> one minor release, maybe two. That means that SolrJ 5.0.0 will probably >> work well with SolrCloud 4.10.x, and maybe 4.9.x, but I would not be >> surprised to find incompatibilities even in a small version spread. You >> may find that a wide version spread works perfectly ... I have not tried >> it. >> >> Thanks, >> Shawn >> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org >> For additional commands, e-mail: dev-h...@lucene.apache.org >> >> > -- Regards, Shalin Shekhar Mangar.
