RE: Java extensions directory vs Excel generation

Unless Java via QSH re-uses a single JVM, I'd call that the opposite of efficient. If it does re-use a single JVM, then it suffers from all the same issues.


"Plus I can call as many Java processes as needed while also switching the JVM in a current job."
Please explain. AFAIK, the one JVM per job is an OS restriction.




-----Original Message-----
From: Richard Schoen [mailto:Richard.Schoen@xxxxxxxxxxxxxxx]
Sent: Monday, January 22, 2018 12:00 PM
To: midrange-l@xxxxxxxxxxxx
Subject: RE: Java extensions directory vs Excel generation

"Plus I can call as many Java processes as needed while also switching the JVM in a current job."

Until the JVM crashes or runs out of memory, then your job has to be restarted. Seen that a bit. Ouch..

If you want to keep Java resident. Better to create a Java based simple app server then to call and consume Java stuff via REST. Queue Dieter...

That keeps Java in memory but also out of process so RPG can do it's thing by sending data queue entries possibly or using REST calls to the Java process which is much easier than mapping Java methods to RPG. Yuk...

BTW: Calling Java via QSH is pretty efficient these days but I agree you want to limit too many simultaneous calls depending on the app needs.

Regards,
Richard Schoen
Director of Document Management
e. richard.schoen@xxxxxxxxxxxxxxx
p. 952.486.6802
w. helpsystems.com
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message: 1
date: Mon, 22 Jan 2018 14:34:17 +0000
from: Justin Taylor <JUSTIN@xxxxxxxxxxxxx>
subject: RE: Java extensions directory vs Excel generation

I assume by "single instance issues", you mean the fact that each job only gets a single JVM, which can't be changed or restarted.

Using Java as your driving language is a viable option, but (for performance reasons) you certainly won't want a ton of RUNJVA from RPG/CL.

"Plus I can call as many Java processes as needed while also switching the JVM in a current job."
Please explain. AFAIK, the one JVM per job is an OS restriction.