Thanks Shawn. Looks like Java 11 is the way to go with -XX:+UseNUMA. Do you see any backward compatibility issue for Solr 8 with Java 11? Can we run Solr 8 built with JDK 8 in Java 11 JRE, or need to rebuild solr with Java 11 JDK?
Best, Wei On Sat, Sep 26, 2020 at 6:44 PM Shawn Heisey <apa...@elyograg.org> wrote: > On 9/26/2020 1:39 PM, Wei wrote: > > Thanks Shawn! Currently we are still using the CMS collector for solr > with > > Java 8. When last evaluated with Solr 7, CMS performs better than G1 for > > our case. When using G1, is it better to upgrade from Java 8 to Java 11? > > From > https://lucene.apache.org/solr/guide/8_4/solr-system-requirements.html, > > seems Java 14 is not officially supported for Solr 8. > > It has been a while since I was working with Solr every day, and when I > was, Java 11 did not yet exist. I have no idea whether Java 11 improves > things beyond Java 8. That said ... all software evolves and usually > improves as time goes by. It is likely that the newer version has SOME > benefit. > > Regarding whether or not Java 14 is supported: There are automated > tests where all the important code branches are run with all major > versions of Java, including pre-release versions, and those tests do > include various garbage collectors. Somebody notices when a combination > doesn't work, and big problems with newer Java versions are something > that gets discussed on our mailing lists. > > Java 14 has been out for a while, with no big problems being discussed > so far. So it is likely that it works with Solr. Can I say for sure? > No. I haven't tried it myself. > > I don't have any hardware available where there is more than one NUMA, > or I would look deeper into this myself. It would be interesting to > find out whether the -XX:+UseNUMA option makes a big difference in > performance. > > Thanks, > Shawn >
