Just an aside on that, it seems that Java can only open 2000 sockets so you will be limited there. That doesn't depend on available hardware. I get around that by executing multiple JVM's on the same machine. It works like a charm.
Cheers Oliver -----Original Message----- From: sebb [mailto:[EMAIL PROTECTED] Sent: Wednesday, 9 May 2007 21:52 To: JMeter Users List Subject: Re: maximum number of threads per JMeter instance 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
