There is no documentation, because there is no fixed limit - it
depends on the test plan, OS, JVM, hardware, network etc..
The only way to determine the limit is to try. For example, if it
works OK for a particular scenario with 10 threads but not with 15,
then the limit is somewhere between 10 and 15.
Having said that, 2000 or more threads is a pretty large number, so
I'm not entirely surprised that there are memory problems. Some OSes
have limits to the number of open sockets, even if memory is not a
problem.
That number of threads is also potentially a huge load on whatever
server is under test - do you really need to run with 7000 threads?
As a work-round:
- use non-GUI mode
- remove all but one listener
- use CSV output
- minimise assertions
- use multiple independent jobs, and combine the results.
On 09/05/07, Sonam Chauhan <[EMAIL PROTECTED]> wrote:
Hi -
Can someone point me to documentation on the maximum number of threads a
single JMeter instance can handle? (I cannot find this information on
Google or the wiki.)
I have a problem with a testcase that has a large number of threads - it
has 2 thread groups with 2000 and 5000 threads each. On a Windows XP SP2
system with 2GB of RAM, java.exe grows to about 350MB before throwing
this exception:
-------------------------
Exception in thread "Thread-1" java.lang.OutOfMemoryError: unable to
create new native thread
at java.lang.Thread.start0(Native Method)
at java.lang.Thread.start(Thread.java:574)
at
org.apache.jmeter.engine.StandardJMeterEngine.run(StandardJMeterEngine.j
ava:387)
at java.lang.Thread.run(Thread.java:595)
-------------------------
The JMeter version is 2.1.1 and the Java version is "1.5.0_10"
-------------------------
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_10-b03)
Java HotSpot(TM) Client VM (build 1.5.0_10-b03, mixed mode)
-------------------------
I tried tweaking two JMeter run script settings: HEAP and NEW. I started
small, and increased the numbers proportionally up until Xmx=1024m but
it was little use - the more I increased HEAP size, the faster I got the
outOfMemory errors.
I also came across some interesting information here about the maximum
number of threads per process:
http://blogs.msdn.com/oldnewthing/archive/2005/07/29/444912.aspx
I tried using '-Xss128k' to reduce stack size per Java thread, but that
did not help either.
Kind regards,
Sonam Chauhan
--
Corporate Express Australia Ltd.
Phone: +61-2-93350725, Email: [EMAIL PROTECTED]
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
