On 4/29/2019 6:46 AM, Bernd Fehling wrote:
while going to change my JAVA from Oracle to openJDK the big question is
which distribution to take?
Currently we use Oracle JDK Java SE 8 because of LTS.
Next would be JDK Java SE 11 again because of LTS but now we have to
change to openJDK.
Any recommendations about openJDK 11 distributions?
( https://www.baeldung.com/oracle-jdk-vs-openjdk )
Also any pros and cons about the different distributions
OpenJDK 8 should work well for any recent Solr release. I think OpenJDK
11 should also be OK as long as the Solr version is very recent.
For the 7.0 release, Java 9 was officially announced as supported. Some
of the early 7.x releases had problems starting with Java 10 or later,
but if you got it running, you were probably OK. The startup problems
were resolved by one of the later 7.x releases.
What about the SOLR components (Tika, UIMA, Zookeeper, Jetty, ...)
are they all tested with openJDK 11?
( https://wiki.openjdk.java.net/display/quality/Quality+Outreach )
Solr is automatically tested with different Java versions. Much of the
dependencies are also tested. If we have a test for it, it's probably
OK. This testing includes Java versions that haven't been released yet,
so hopefully we can support each new major Java version as soon as it is
released.
The goal with tests in the Solr codebase is to make sure that Solr and
all of its dependencies are working correctly. There may be things that
are not being tested that SHOULD be tested ... as these are found, they
are slowly fixed.
Java's accelerated release schedule, license changes, and trying to
document what's supported has been a topic of discussion among the Solr
committers. Here's the current status:
https://wiki.apache.org/solr/SolrJavaVersions
What about the recommendation in the Solr Ref Guide?
They point to Oracle:
...
If you don’t have the required version, or if the java command is not
found, download and install the latest version from Oracle at
http://www.oracle.com/technetwork/java/javase/downloads/index.html
...
Shouldn't they better point to openJDK?
The documentation for Solr 8.0 is being updated to match the info on the
wiki page that I linked above.
Thanks,
Shawn
