RE: AS/400 and Java (Tomcat on AS400)

["David Morris" <David.Morris@xxxxxxxxxxxxx>]

Alex,

We run a fairly high transaction site with Tomcat 4.1.12 and
find that it is substantially faster than 3.2.4. Many of the
performance improvements are in how Tomcat compiles
JSP pages and caches custom tags. If you are not using
these the increase may not be as great. The Coyote
connector is supposed to be faster even when running
standalone but I didn't see any difference.

In our case performance issues are generally influenced
by connection pooling working correctly, how we set up the JVM
(memory and garbage collection), subsystem configuration, jar
optimization (not supposed to matter but it does), whether
reloading is turned on, logging levels, and connection types
(native or non-native).  Since it sounds like you are running
the same stuff with the same connections etc. I would
concentrate on the JVM and subsystem configuration. Also
look at your server.xml file to make sure your logging isn't
at trace or something and reloading is off.

Beyond that, I have profiled that site and found several
opportunities to substantially reduce memory usage by
restructuring  a few classes. Two days of profiling in that
case led to a 25% performance improvement.

David Morris

>>> apinsky@aeropostale.com 12/11/02 12:53PM >>>
Hi,
I was able to start Tomcat4.1.12(stand alone) using startup.sh
script(Thanks Patrick). Works fine but it is still a bit slower than
IBM's version configured as in-process with Apache webserver. I wonder
if configure Tomcat4.1.12 as in-process will we see a performance
boost?
One more problem is that I can't distribute our app as a jar file. At
Tomcat startup time get an error message:
'Exception processing JAR at resource path /WEB-INF/lib/aeronet.jar'.
The same jar works fine under Tomcat3.2.4. When I deploy app as a set of
classes - works fine.
Any recommendations?
Thanks,
Alex Pinsky