>> Out of curiousity, could you try opening up your jmeter.bat and >> increasing the values in the HEAP variable. Sepecifically, change >> -Xmx512m up to -Xmx2048m in hopes that you're running into a >> limitation with the default memory settings. > >Agreed.
The test results I observed were after setting up the value to heap to a higher value than the default value. I had tried values from -Xmx1024m to -Xmx2048m but there was only a very slight improvement. Also at the instant just before the JMeter crash, there was ample amount of free memory, both RAM and VM. The systems had 3 GB RAM and 10-15 GB of available VM. The VM usage was not so high that we could expect a "swap space" error, and hence the concern at our end. >> On a hunch, maybe one of the samplers or its dependencies allocates >> enough memory to hold the file, or the file upload process is >> allocating a String/StringBuffer that temporarily holds a MIME-Encoded >> version of the file. When you get enough threads on the same upload >> step, you suddenly have 30 threads holding 30MB of data each. This >> could be the reason that it rarely happens on the 10MB files -- the >> chances of 60 threads being on the same sampler are much lower. This >> is all idle speculation, though. > >Could well be true. Looks like a possibility. As a cross check I will try this from Load Runner. I know, in the past a few teams have successfully tested such scenarios using LR. I think I should give it a try to see he behavior. > Ramp-up should be set to limit how quickly the threads are started. > 5-10 per second should be fine, 100/s is almost certainly too high. Okay I will keep this is mind when running tests in future. > > These error are not of one common nature. But most of them were due to > > "Regular Expression Extractor" not being able to extract the data from > > previous response. > This is presumably because the response was not as expected, which > probably means that the server was returning different data. Either > there are variations in the output that the test plan does not allow > for, or the server is misbehaving under load. Agreed. But them we should see the same error in case we run 70 users from 1 system. But actually, if we run 70 from 1 system, we get no errors. But with 35 from 2 systems, each governed by a central server, we see 50% error. Any clues? Or more tests that you could suggest to isolate the cause? > Which Http Sampler are you using? HttpClient or the default Java one? We are using HTTP Request Sampler of JMeter. But I am not sure if I understood the question correctly. Thanks for all the suggestions and help. Gaurav sebb-2-2 wrote: > > On 16/01/2009, Thomas Johnson <[email protected]> wrote: >> On Fri, Jan 16, 2009 at 4:21 AM, GeeTee <[email protected]> >> wrote: >> > >> > Hi sebb, >> > >> > Thanks for your response. Following are the details: >> > >> >>>What is the exact Java error message? >> >>>AFAIK,"swap space" is an OS error rather than a JVM error >> > Exception java.lang.OutOfMemoryError: requested 36052328 bytes for >> > promotion. >> > Out of swap space? >> >> >> Out of curiousity, could you try opening up your jmeter.bat and >> increasing the values in the HEAP variable. Sepecifically, change >> -Xmx512m up to -Xmx2048m in hopes that you're running into a >> limitation with the default memory settings. > > Agreed. > >> Run "java -X" for more information on these, or open "bin/jmeter" in a >> text editor >> >> On a hunch, maybe one of the samplers or its dependencies allocates >> enough memory to hold the file, or the file upload process is >> allocating a String/StringBuffer that temporarily holds a MIME-Encoded >> version of the file. When you get enough threads on the same upload >> step, you suddenly have 30 threads holding 30MB of data each. This >> could be the reason that it rarely happens on the 10MB files -- the >> chances of 60 threads being on the same sampler are much lower. This >> is all idle speculation, though. >> > > Could well be true. > >> > This is shown on the console launched by jmeter.bat. Please let me >> know how >> > I can see the JVM error. >> > >> >> The full exception details might be visible in jmeter.log > > Probably not, as running out of memory may well stop logging from > working... > >> >> >>>Ramp-up should not be set as low as this or JMeter may have problems >> > starting. >> > >> > Okay. So what is the minimum ramp up that we should set? We had been >> asked >> > to load test for 800 users accessing the online service >> simultaneously. As >> > such we had set up 8 instances of JMeter on different systems and had >> 100 >> > users with 1 sec. ramp up on each (Please note that this was one of >> the >> > tests on which more than 10 MB of file upload would cause swap space >> error >> > for 30 users or more). Please provide your inputs on how we should >> have >> > proceeded. >> > > > Ramp-up should be set to limit how quickly the threads are started. > 5-10 per second should be fine, 100/s is almost certainly too high. > >> >>> What errors are these? >> > These error are not of one common nature. But most of them were due to >> > "Regular Expression Extractor" not being able to extract the data from >> > previous response. > > This is presumably because the response was not as expected, which > probably means that the server was returning different data. Either > there are variations in the output that the test plan does not allow > for, or the server is misbehaving under load. > >> > This happened on running 35 threads from 2 systems >> > controlled by a single server. For heavier loads (70 users from 2 >> machines >> > controlled by a single server) I did not see the response as I had >> disabled >> > the "View Results Tree" listener as it is quite memory intensive, and >> > instead used "Aggregate Graph" listener. I did not log the results. >> > > > Aggregate Graph is also memory intensive. Use Summary Report instead. > >> > Just to add to my previous post, we have seen this problem only with >> scripts >> > that upload a file to the online service server. For other services, >> that do >> > not upload anything and rather just hit the various servlets / JSPs, >> we have >> > not seen this error. >> > > > Which Http Sampler are you using? HttpClient or the default Java one? > >> > Thanks again for the help. >> > Gaurav >> > >> > >> > >> > sebb-2-2 wrote: >> >> >> >> On 11/01/2009, GeeTee <[email protected]> wrote: >> >>> >> >>> Hi everyone, >> >>> >> >>> We wanted to load test our online services using JMeter but were >> unable >> >>> to >> >>> load test for heavy loads due to JMeter crashes with "swap space" >> error. >> >>> I >> >> >> >> What is the exact Java error message? >> >> AFAIK,"swap space" is an OS error rather than a JVM error. >> >> >> >>> had a look at other such threads over here and we have already >> tried out >> >>> those suggestions with no success (e.g. setting heap correctly in >> >>> jmeter.bat) >> >>> >> >>> I will give you some insight into out online application. It is >> actually >> >>> a >> >>> hybrid application, i.e. it is an online application embedded in a >> >>> desktop >> >>> client. It is basically a set of Servlets and JSPs and uses a >> custom >> >>> "XML >> >>> over HTTP" protocol for communication (please note that we do not >> use >> >>> SOAP). >> >>> Using these services a user can upload videos and stills to >> different >> >>> websites (some of our own and some third-party). We have faced 2 >> issues >> >>> that >> >>> seem to be related to each other. >> >>> >> >>> PROBLEM1: >> >>> We had been asked to test for total 200-800 simultaneous (i.e. ramp >> up = >> >>> 1 >> >>> sec) users. >> >> >> >> Ramp-up should not be set as low as this or JMeter may have problems >> >> starting. >> >> >> >>> After reading a few documents we decided on running 50-75 >> >>> threads from a single machine and have a central controller >> >>> (jmeter-server.bat method). We were unsuccessful in our attempts. >> For >> >>> example, at one instance we tried to run 35 threads from 2 machines >> >>> (total >> >>> 70 threads only) controlled by a JMeter server. We received 50-60% >> >>> errors. >> >> >> >> What errors are these? >> >> >> >>> Then we ran 70 threads from 1 machine. Result - 0% error. Since the >> >>> service >> >>> was same in both the cases, it seems to be a problem related to >> JMeter. >> >>> Even >> >>> with 25 users per system from 2 systems, the problem exists. >> >>> >> >>> Machine config: Pentium Dual Core machines 2.8 GHz, 3 GB RAM, 320 >> GB >> >>> Hard >> >>> Disc, 10 GB Virtual Memory, Win XP Professional SP2. The systems >> had no >> >>> other softwares installed. JMeter version was 2.3.1 (we also tried >> 2.3.2 >> >>> but >> >>> observed the same results) >> >>> >> >>> PROBLEM2: >> >>> Due to Problem1, we decided that we will run the scripts from 8-10 >> >>> separate >> >>> systems by manually triggering them. And would later collate the >> >>> response >> >>> timings from each system. We wanted to upload files (present on >> hard >> >>> disc) >> >>> to the websites for which the service had been written. File size >> varied >> >>> from 4MB to 60MB. Using file size = 4MB, I was able to run 100 >> threads >> >>> from >> >>> 1 system without problem. But with file size = 30MB or more, even >> 10 >> >>> threads >> >>> would cause JMeter to crash frequently. On Vista, the situation was >> >>> slightly >> >>> better but still I could not go beyond 20 users for 30 MB files. As >> such >> >>> we >> >>> have not been able to load test for heavy files. >> >> >> >> Which Http Sampler are you using? >> >> >> >>> Machine Config: Same as that for Problem1 >> >>> >> >>> Sorry for such a lengthy email. I wanted to provide all the >> information >> >>> that >> >>> I had with me. >> >>> >> >>> Thanks, >> >>> Gaurav Tripathi >> >>> >> >>> -- >> >>> View this message in context: >> >>> >> http://www.nabble.com/Jmeter-crashes-with-%22swap-space%22-error-for-us-tp21402014p21402014.html >> >>> Sent from the JMeter - User mailing list archive at Nabble.com. >> >>> >> >>> >> >>> >> --------------------------------------------------------------------- >> >>> 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] >> >> >> >> >> >> >> > >> > -- >> > View this message in context: >> http://www.nabble.com/Jmeter-crashes-with-%22swap-space%22-error-for-us-tp21402014p21491893.html >> > Sent from the JMeter - User mailing list archive at Nabble.com. >> > >> > >> > --------------------------------------------------------------------- >> > 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] >> >> > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > > > -- View this message in context: http://www.nabble.com/Jmeter-crashes-with-%22swap-space%22-error-for-us-tp21402014p21505427.html Sent from the JMeter - User mailing list archive at Nabble.com. --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
