tuning java

[gajowi]

Can you please add some information on:

• passing java options
• choosing/tuning java options to pass
  and set some default java options that are sufficient to run ncwms if/when it is enabled (maybe -Xmx2G).

I've found that setting JAVA_OPTS in the environment is picked up by tomcat. This can be done with the docker run --env option or the docker-compose environment configuration option. It might be good to define JAVA_OPTS in the dockerfile(s), as a reference as well as a means of setting hyrax-docker specific defaults. Rece

Note that it is well known that java in docker/containers can't easily determine how much memory is available/allowed so there is an implicit expectation that the environment will have to be tuned for given use-cases.

I don't think it will help much for me to alter the README and make a PR. I'm willing to do so if you ask.

Gareth

cross-ref: https://groups.google.com/a/opendap.org/forum/#!topic/support/xLoTzkg6s6A

[gajowi]

I just tried shifting to one of the latest "c7" builds and find that JAVA_OPTS no longer works. With a bit of poking about and trial and error I find CATALINA_OPTS now works.
I think java has changed - perhaps JAVACMD_OPTS is now expected - but a "catalina" setting seems more appropriate in any case so I'm personally happy to stick with that.
You might update the README...