On 12/10/23 20:36, Jim Morgan wrote:
Now we're looking at java. Its currently running on openjdk-8. I've tried
upgrading to openjdk-11 and openjdk-13. The process, as this is Ubuntu is
basically.
Don't use Java 13. It is a non-LTS release. Non-LTS releases are only
supported for 6 months, so that version has been out of support for more
than three years -- support ended in March 2020.
Java 11 is a good solid choice. Java 17 seems to perform a little
better than 11 on Solr 9.x, but I haven't actually measured it. Java 8,
11, 17, and 21 are the current LTS releases.
https://en.wikipedia.org/wiki/Java_version_history
I personally wouldn't trust Solr 8.x with Java 17, as that's a jump of 9
major Java versions ... but others have done it and I haven't seen
reports of problems. I use Java 17 with Solr 9.x on Ubuntu.
With Java 11 or later, I think it would be a good idea to switch garbage
collection to ZGC. I have this in my /etc/default/solr.in.sh:
GC_TUNE=" \
-XX:+UnlockExperimentalVMOptions \
-XX:+UseZGC \
-XX:+ParallelRefProcEnabled \
-XX:+ExplicitGCInvokesConcurrent \
-XX:+AlwaysPreTouch \
-XX:+UseNUMA \
"
Side note: You should be using update-java-alternatives instead of
update-alternatives. It will update ALL of the binaries for java, not
just /usr/bin/java.
Showing available options:
elyograg@smeagol:~$ update-java-alternatives -l
java-1.11.0-openjdk-amd64 1111
/usr/lib/jvm/java-1.11.0-openjdk-amd64
java-1.17.0-openjdk-amd64 1711
/usr/lib/jvm/java-1.17.0-openjdk-amd64
java-1.8.0-openjdk-amd64 1081
/usr/lib/jvm/java-1.8.0-openjdk-amd64
You would then follow that with something like:
update-java-alternatives -s java-1.11.0-openjdk-amd64
If Solr will not start with Java 11, look in solr.log and
solr-NNNN-console.log for info about why it failed.
Thanks,
Shawn
