RE: Optimizing Native Java

The most important thing is to understand where the time goes. Situations
when there are no bottlenecks and every class contributes to poor
performance in equal measure are pretty rare. What you need is to a)
understand what threads are primarily involved in productive work and then
b) draw a chart describing what each of these thereads is busy doing (e.g.
50% of the time spent waiting for JDBC queries and 50% of the time doing XML
processing). You can hardly achieve this without Java performance analysis
tools for System i. IBM Job Watcher is what immediately springs to mind, but
JW data is not easy to analyse, to say the least. There are other tools,
some of them pretty good, but none of them in the Open Source domain, as far
as I know.  

As for the magic button, there is none, I'm afraid. I would be suprised if
memory alone could make you happy. That is, unless you're running your JVM
in a 50MB pool.  

Lo
-----Original Message-----
From: albartell
To: 'Java Programming on and around the iSeries / AS400'
Sent: 10/16/06 4:12 PM
Subject: Optimizing Native Java

Hi All,
 
I am just completing a project where I wrote a Java proxy of sorts and
there
were a bunch of third party jar files involved in the mix. To make a
long
story short we are not satisfied with the performance we are getting out
of
the Java processes on the iSeries (note the Java is running in it's own
job
listening to a data queue - only one JVM startup).  We have run the
CRTJVAPGM against all .class and .jar files involved and are wondering
are
there any other mechanisms to look at concerning getting more speed on
the
Java end?
 
Obviously one solution would be to throw more memory at it, but is there
a
way to section off the memory so this Java process gets sole use of it
(similar to how you can do the same for Websphere Application Server)?
 
Any other idea's?
 
Aaron Bartell
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