Re: Mixing 4.x SolrJ and Solr.war - compatible?

[Gili Nachum <gi...@gmail.com>]

So, It seems I can't upgrade Solr beyond 4.7 as long as I'm running SolrJ
on Java6 JVM.
With any luck I might be able to compile SolrJ that's newer than 4.7 with
Java6. I'll check that next.
Thanks Shawn. That's very helping!

On Wed, Dec 31, 2014 at 6:54 PM, Shawn Heisey <ap...@elyograg.org> wrote:

> On 12/31/2014 6:23 AM, Gili Nachum wrote:
> > Can I use SolrJ v4.7 with the latest 4.x Solr.war?
> > Should I switch the writer from Javabin, back to XML to ensure
> > compatibility?
> >
> http://wiki.apache.org/solr/Solrj#SolrJ.2FSolr_cross-version_compatibility
> >
> > I'm using CloudSolrServer. My client is running on Java6 so I can't go
> > beyond 4.7.
>
> If you're running SolrCloud, I would not try it.  SolrCloud is evolving
> very quickly and so many things have changed that running mismatched
> versions is likely to break.  I have tried CloudSolrServer from 4.6.0
> against a SolrCloud running 4.2.1, and a simple query will not work
> because of changes in the data contained in zookeeper.
>
> If you're not using CloudSolrServer, it should work very well even with
> a wide version discrepancy.
>
> Switching to XML is not required.  The javabin version has only changed
> once, in version 3.1.0.  It has been stable since that time.
>
> Thanks,
> Shawn
>
>

Re: Mixing 4.x SolrJ and Solr.war - compatible?

[Shawn Heisey <ap...@elyograg.org>]

On 1/1/2015 6:34 AM, Gili Nachum wrote:
> So, It seems I can't upgrade Solr beyond 4.7 as long as I'm running SolrJ
> on Java6 JVM.
> With any luck I might be able to compile SolrJ that's newer than 4.7 with
> Java6. I'll check that next.
> Thanks Shawn. That's very helping!

Solr 4.8 and later (compared to 4.7) have a very large number of code
changes that will not compile under Java 6.  It would be a *major*
undertaking to change those back.  When the project declared that Java 7
was the minimum version, we weren't just making a statement ... it
really did become the minimum requirement.

Oracle has stopped providing support for Java 6.  Java 7 will also reach
end of support in April 2015, so you might actually want to consider
moving to Java 8, which has even more performance improvements over Java 7.

Along with the latest Java 7 or Java 8, you should probably change your
garbage collection tuning to G1.  With a lot of invaluable help from
Oracle employees, I've worked out a good set of parameters:

https://wiki.apache.org/solr/ShawnHeisey#GC_Tuning

Thanks,
Shawn