Mailing-List: contact jmeter-user-help@jakarta.apache.org; run by ezmlm
Message-ID: <3F55AF26.7040202@bmjgroup.com>
Date: Wed, 03 Sep 2003 10:06:46 +0100
From: "Duncan Frostick" <dfrostick@bmjgroup.com>
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To: JMeter Users List <jmeter-user@jakarta.apache.org>
Subject: Re: Memory / CPU usage
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That's Java for you. As great as the portability and libs are, it's such 
a painfully slow lang for performance tasks. I have a Solaris server 
with 2GB of RAM and it can't do 100 threads without giving me stupidly 
high response times (of close to an hour...) on some requests.

Its a pity because JMeter is such a fantastically good tool when it 
works, its just let down by performance issues. If you want to load test 
at anything like a high load with JMeter you need several high powered 
servers doing it in unision to spread the threads.
 
I was trying to use the GCJ compiler - which claims to compile java 
bytecode to machine code - to increase performance but I couldn't get it 
working, that could be a possible performance boost. My general rule of 
thumb is that for anything above 75 users JMeter/Java is too resource 
hungry to give accurate results on my hardware.

And now I'm trying high-loads, thats a problem. However, IBM have a 
nifty if hard to configure tool called 'stress'. It's written in C so it 
performs very well, just lacks a lot of JMeters great functionality. You 
can find it online if you serach for IBM Web Performance Tools.

Perhaps a port of JMeter to C++ should be considered? I know this would 
involve doing a lot of painfully boring networking and threading code 
but the performance gain would be huge.

Cheers, Duncan


Mark McWhinney wrote:

>Hi all,
>
>I am a long time LoadRunner user but am new to JMeter.  I am impressed with
>its functionality.  It is a lot closer to LoadRunner than many of us in the
>LoadRunner community realize.
>
>I am going through the usual newbie issues but am actually reading the
>manual and figuring it out.
>
>I ran a test with one thread group with 30 threads that had six HTTP
>requests with a 5 second wait time between each request.  I maxed out the
>CPU at about 20 to 25 users on a 800 MHz Windows 2000 machine.  Memory
>utilization was about 350 Mbytes.  Is that typical?  I am really going to
>need 10 machines to do a 250 user load test or am I missing something?
>
>
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