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
