Oh I forgot to mention. Currently, the max thread size is 3000.
Note that both the client processes will run simultaniously. One with
more threads runs for long and one with less number of threads stops
quickly.
Moreover if tomcat runs out of threads then it will clearly put the info
in the log telling that 'you are running out of threads'
Bhaskar
Allistair Crossley wrote:
Hi,
I would think that is because Tomcat's max threads by default is usually around 75. I you fire 10 at it then they all get serviced immediately.
If you send 1000, all 75 get taken up, meaning a queue forms for the 1000-75 remaining threads until Tomcat has spare threads for them.
Allistair
-----Original Message-----
From: Bhaskar [mailto:[EMAIL PROTECTED]
Sent: 13 July 2005 09:26
To: Tomcat Users List
Subject: Re: Perf Issue: HttpClient.executeMethod takes more time if
there are more number of threads in the process
In my testbox, both of the following processes are running
simultaniously:
java testprocess 1: 1000 threads (avg time to execute the
executeMethod:1723.61 ms)
java testprocess 2: 10 threads (avg resp time to execute the
executeMethod: 32 ms)
If it is to do with max processor attribute of Tomcat server
side then
how come I am seeing good response with another test java
process which
had less number of threads ?
More over in tomcat, I am seeing the average response time as
12 to 20
ms. If there is a problem in tomcat side, then i might have seen huge
numbers here.
Bhaskar
Allistair Crossley wrote:
Complete stab in the dark here ... Tomcat serves a maximum
number of threads at a time (request processing threads). It
may be that Tomcat's timings are accurate for the threads
*when* it executes them, but your HTTP Client will be seeing
a queue when Tomcat has no spare request thread capacity. You
can tweak this with the max processors attribute for Tomcat's
connectors.
Just a guess, take with pinch of salt.
Allistair
-----Original Message-----
From: Bhaskar [mailto:[EMAIL PROTECTED]
Sent: 13 July 2005 08:09
To: Tomcat Users List
Subject: Perf Issue: HttpClient.executeMethod takes more
time if there
are more number of threads in the process
Hi,
I am running tomcat 5.0.28 on Linux (2.6.9-5.ELsmp #1 SMP Wed Jan 5
19:29:47 EST 2005 x86_64 x86_64 x86_64 GNU/Linux).
I am having another test box which runs java process with 1000
threads(each thread will send 10000 http requests to above
tomcat server
in the delay of 1 ms). This test process uses the
HttpCommon api's to
make use of http connection pool's keep alive capability.
Each thread in the above test process will send the post
request to the
tomcat using HttpClient.excecuteMethod.
If I check the avg response time in the tomcat server it is
somewhere
around 12 to 20 ms
But in the test process, the time taken to execute the
HttpClient.executeMethod varies between 3 ms to 21855 ms
(avg: 1723.61 ms)
Parallely (still above test process is running) I start same test
process from the same test box with 10 threads (each thread
will send 10
http requests to above tomcat in the delay of 1 ms). Now I
see the time
taken to execute the HttpCleint.executeMethod varies between
9ms to 146
ms (avg: 32.47 ms).
The difference between first process and second process is
number of
threads. I am trying to understand the reason on why
HttpClient.executeMethod is taking more time if I have more
number of
threads trying to send the http request?
Do I need to fine tune something to make it better? Is it a
expected
behaviour ? if yes, any reason?
Or I am doing something wrong my code ?
TIA,
Bhaskar
PS: java version "1.4.2-02"
Java(TM) 2 Runtime Environment, Standard Edition (build
Blackdown-1.4.2-02)
Java HotSpot(TM) Client VM (build Blackdown-1.4.2-02, mixed mode)
At some point if I check the number of established connections thru
netstat in test box, I see the following figure:
# netstat -a|grep tomcatserver|grep ESTABLISHED|wc -l
528
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