Re: JVM initialization memory concerns..?

On Wed, Apr 22, 2009 at 1:16 PM, Jonathan Keeney <jonkeeney@xxxxxxxxx> wrote:

- Am I right in thinking that a new JVM is initialized for each interactive
job that will be calling this new module?  I've read that the JVM is
integrated with i5/OS in a unique way that makes it function differently
from JVMs in other OSes, but I'm not well-versed enough in these things to
understand the repercussions of that.

Correct, each job gets it's own JVM.

- If this is the case, is it reasonable to expect that our i5 would be
overly taxed by having a large number (25? 30?) of these jobs running at
once?

Depends on the i5 and how much memory you have. But it's possible (likely?).

- Is there any way to initialize one JVM and have all these sessions share
it?  Would that even be beneficial if it were possible?

Sure, consider having a job running non-stop in batch handle the Java
code, communicate with it using data queues.

So your interactive (and batch) programs would call a procedure that
puts an entry into a data queue and waits for a reply. The server job
would pick up the entry, make the required java calls and place the
reply back onto a data queue.

You could even code it so that as the queue gets backed up, more jobs
are started to process the requests.

Should find plenty of examples of this technique on the web and in the archives.

HTH,
Charles