RE: [WEB400] New System Development Tomcat Tuning

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

Joe,

I am using a standard Tomcat build with the default settings with the
exception that the startup script that I use specifies more memory.
I compiled everything to level 40 per IBM's recommendation and
include the native jar files. It takes me about 15 minutes to set this

up on a new system (not including the compile time). The tuning
steps I followed are in the iSeries Java performance FAQ and
should be followed for any Java program. Tomcat tuning is
pretty much deciding how many threads to start, what you want
to load on startup, what resources Tomcat will manage like
connection pools, and how you want JSPs compiled. From
experience with Tomcat, Oracle, and DB2, I would Tomcat
at about 1/10 of DB2, and 1/30th of Oracle.

Since I can't run your tests, would you be interested in setting
up a standalone Tomcat build on your system and trying it out?
I could get you started pretty quickly.

I did use jMeter when I tested Tomcat against WebSphere last year.
That was on a system that was constrained for memory and Tomcat
performed far better, which I would expect.

David Morris


>>> joepluta@PlutaBrothers.com 05/10/02 10:45AM >>>
> From: David Morris
>
> What version of Tomcat? I use 4.0.3. We have significantly more
> than 20 users and never see the kind of response that you are
> experiencing. I built my own startup scripts that give Tomcat
> the memory it needs to run -- what values did you use? Do you
> use native access? I am running Tomcat standalone, which is
> supposed to run slower than IBM's installation but I wouldn't bet
> on it (what do they have to gain by optimizing Tomcat?).

I'm using the version of Tomcat that is shipped with the AS/400.
Remember
that in my tests every user is hitting the enter key every 500ms, which
is a
far higher load than a real application ever sees.  Have you tried
using a
stress testing package?  I use WebRoller and it works quite well, and
it
gets rid of any subjective measurements.

Again, as to settings, I'm using the default settings for both
WebSphere and
Tomcat.  I don't claim to be an expert at tuning, but I also don't want
to
become an expert at tuning.  Same reason I prefer DB2 over Oracle.  An
Oracle DBA can tune Oracle to perform extremely well, but that means I
need
an Oracle DBA.  Perhaps I can tune Tomcat, but that means I have to
learn
how to tune Tomcat.  Don't wanna.


> How hard would it be for me to duplicate your test on my system?

Pretty much impossible.  It's my product development environment.