Re: sluggish java program

["Mike Silvers" <msilvers@xxxxxxxxxxx>]

You are correct..... when the java class is instanced, the java program is
created on the iSeries.  It is created using the command defaults for the
CRTJVAPGM command.  If you did not change these defaults, the optimization
level is at 10.  I believe that this causes the iSeries java program to be
compiled at different times (I'm not sure what the criteria is for
compiling).  If you compile the jar file at optimization level 40, the java
program will only recompile when the class file is changed.  There is a give
and take for the different optimization levels.  At level 40 there is almost
no debugging supported.  At level 10 all debugging is supported.

Mike


----- Original Message -----
From: "Urbanek, Marty" <Marty_Urbanek@stercomm.com>
To: <java400-l@midrange.com>
Sent: Thursday, November 15, 2001 12:55 PM
Subject: Re: sluggish java program


> I thought that once the class has been implicity compiled and a java
program
> object created, that it should not have to be compiled again via
CRTJVAPGM.
> Therefor the slowness should only occur once.
>
> I have a java program that behaves similarly. I subscribe to the slow
class
> loading theory. If possible, perhaps you could run your server
interactively
> and start your JVM with the -V option so it will display the classes as
they
> are loaded. This was very enlightening for me. It is amazing how many
> classes it has to load. It takes significant time, at least on my program.
I
> am seeking a way to "pre-load" all this stuff so it will be ready when a
> real request comes in.
>
> -Marty
>
> -------- original message -------------
>
>
> One thing about using jar files... to enhance performance, compile the jar
> files before they are used (CRTJVAPGM).  I always submit these compile
jobs
> to batch because it is a big job.  If you do not compile these before
using
> them, the classes will be compiled the first time they are instanced.
This
> might be what is happening....
>
> Mike
>
> ----- Original Message -----
> From: <AAnuszewski@hammer.net>
> To: <java400-l@midrange.com>
> Sent: Thursday, November 15, 2001 12:06 PM
> Subject: Re: sluggish java program
>
>
> >
> >
> >
> > No.  It is a simple tcp/ip socket server.  It does use the jt400.jar to
> manage
> > connections with a data area and some data queues.
> >
> > Amy
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