On 11/09/2009, Jakub Białek <[email protected]> wrote: > Obviously JMeter supports much more than 30 threads. But if you use > JMeter to simulate e.g. 200 concurrent users to check load and > response time of your application then you can use e.g.: > - 1 jmeter instance with 200 threads or > - 2 jmeter instances with 100 threads each or > - 4 jmeter instances with 50 threads each or > - 8 jmeter instances with 25 threads each > ...... > The last solution is the best if you want simulate real load that can > be generated by 200 real users. The first solution is the worst. I'll > explain it below. > Let's assume that you have 1 core CPU. Some facts: > - at the moment on your cpu can run only one process/thread to > simulate multitasking OS gives small amount of time to each > process/thread and changes the process/thread context > - changing/switching process cost several cpu cycles because cpu > registers have to be filled with corresponding data > - changing/switching thread is cheaper > - not only jmeter runs on your machine also many other > application/process bounded to the OS, so jmeter is often dispossess > and waiting for cpu cycles > - not only workers threads of jmeter runs, also other java threads > e.g. GCThread, all those threads compete for cpu > - when one thread/process is running others are sleeping/waiting > - process/thread can by disposed at any time of execution
These are all true, but: > Conclusion: > - 200 jmeter threads don't mean 200 concurrent users, load generated > by those jmeter instances will be much less than this by 200 > concurrent real users That's not a valid conclusion unless JMeter is running out of CPU. In general, a single JMeter thread can generate *more* load than a single user, because it can send requests much faster than a human. > - more jmeter threads more time spent on switching context, less time > used by jmeter worker threads > - any worker thread can be disposed (and wait when rest 199 threads > will take their cpu time) after receiving answer from server but > before calculate time that call to server took so this time will be > incorrect > > So if your goal is to simulate as good as possible load generated by > many users then use so much jmeter instances (computers) as you can > with as less as possible threads on each jmeter instance. Otherwise > your results can be far from reality and you can be surprised why your > application can't handle with those users even though jmeter stress > tests passed. Again, I disagree with this. > If someone is interested in comparison how performance of my > application changes depending on jmeter configuration (number of > threads and number of instances) I can do that test. I have 10 servers > with 2 CPU each and each CPU with 4 core. Those servers can be used as > a JMeter clients. > > > Best regards, > Jakub > > > W dniu 11 września 2009 15:54 użytkownik sebb <[email protected]> napisał: > > > On 11/09/2009, Jakub Białek <[email protected]> wrote: > >> How about tomcat is it on linux or windows machine? Make sure that OS > >> doesn't limit the max number of inbound connection. > >> > >> Jakub > >> > >> BTW. I think that 200 thread on 1 jmeter instance are to many if you > >> don't have cpus that support 64 threads simultaneously ;) . I usually > >> use no more than 50 on 8 core system. > >> > > > > A single JMeter instance can support many more than 50 threads, > > depending on the test plan. > > > >> > >> 2009/9/11 Mytho Logic <[email protected]>: > >> > Hi, > >> > > >> > I tried with 550 threads in tomcat for 500 concurrent users. But not > >> > succeed. > >> > > >> > Jmeter Client:- > >> > System: Windows XP Professional Verison 2002 SP2 > >> > Computer: Intel(R) Core(TM)2 CPU 6300 @ 1.86 Ghz 1.86 GHz, 1.97 GB of > RAM > >> > > >> > Jmeter Server:- > >> > System: Windows XP Professional x64 Edition Verison 2003 SP2 > >> > Computer: Intel(R) Xeon(R) CPU 5130 @ 2.00 Ghz 2.00 GHz, 8.00 GB of RAM > >> > > >> > Thanks > >> > Maumita > >> > > >> > > >> > 2009/9/11 Jakub Białek <[email protected]> > >> > > >> >> If you have 500 (truly) concurrent users then you need at least 500 > >> >> threads in tomcat, try with 550 thread. > >> >> > >> >> You run jmeter on windows or linux os? > >> >> > >> >> Best regards, > >> >> Jakub > >> >> > >> >> 2009/9/11 Mytho Logic <[email protected]>: > >> >> > Hi, > >> >> > > >> >> > I changed the maxthreads limit in tomcat server.xml to 400 and > tried the > >> >> > same testplan again..but few sample requests gets failed and throws > >> >> > exception. > >> >> > what should I do to solve the problem. > >> >> > > >> >> > Exception:- > >> >> > > >> >> > java.net.ConnectException: Connection refused: connect > >> >> > at java.net.PlainSocketImpl.socketConnect(Native Method) > >> >> > at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333) > >> >> > at > java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195) > >> >> > at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182) > >> >> > at java.net.Socket.connect(Socket.java:519) > >> >> > at java.net.Socket.connect(Socket.java:469) > >> >> > at sun.net.NetworkClient.doConnect(NetworkClient.java:157) > >> >> > at sun.net.www.http.HttpClient.openServer(HttpClient.java:382) > >> >> > at sun.net.www.http.HttpClient.openServer(HttpClient.java:494) > >> >> > at sun.net.www.http.HttpClient.<init>(HttpClient.java:231) > >> >> > at sun.net.www.http.HttpClient.New(HttpClient.java:304) > >> >> > at sun.net.www.http.HttpClient.New(HttpClient.java:316) > >> >> > at > >> >> > > >> >> > sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:817) > >> >> > at > >> >> > > >> >> > sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:769) > >> >> > at > >> >> > > >> >> > sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:694) > >> >> > at > >> >> > > >> >> > org.apache.jmeter.protocol.http.sampler.HTTPSampler.sample(HTTPSampler.java:431) > >> >> > at > >> >> > > >> >> > org.apache.jmeter.protocol.http.sampler.HTTPSamplerBase.sample(HTTPSamplerBase.java:1021) > >> >> > at > >> >> > > >> >> > org.apache.jmeter.protocol.http.sampler.HTTPSamplerBase.sample(HTTPSamplerBase.java:1007) > >> >> > at > org.apache.jmeter.threads.JMeterThread.run(JMeterThread.java:290) > >> >> > at java.lang.Thread.run(Thread.java:595) > >> >> > > >> >> > Thanks > >> >> > Maumita > >> >> > > >> >> > > >> >> > On Fri, Sep 11, 2009 at 3:07 PM, sebb <[email protected]> wrote: > >> >> > > >> >> >> On 11/09/2009, Mytho Logic <[email protected]> wrote: > >> >> >> > Hi, > >> >> >> > > >> >> >> > In tomcat server.xml, I changed the maxtheads limit to 300 and > kept > >> >> >> > JAVA_OPTS=-Xms512m -Xmx1024m > >> >> >> > > >> >> >> > But not succeed.I am getting same "java.net.ConnectException: > >> >> Connection > >> >> >> > refused: connect" exception. Am I missing anything to change in > >> >> >> server.xml > >> >> >> > file. > >> >> >> > The machine on which tomcat server is running has 2 GB RAM. > >> >> >> > > >> >> >> > Please help on this. > >> >> >> > >> >> >> This appears to be a Tomcat configuaration issue. > >> >> >> > >> >> >> Read the Tomcat documentation carefully, and if that does not > answer > >> >> >> your query, then post a question on the Tomcat user list. > >> >> >> > >> >> >> > Thanks > >> >> >> > Maumita > >> >> >> > > >> >> >> > > >> >> >> > On Fri, Sep 11, 2009 at 10:15 AM, Deepak Shetty > <[email protected]> > >> >> >> wrote: > >> >> >> > > >> >> >> > > Hi > >> >> >> > > http://tomcat.apache.org/tomcat-5.5-doc/config/http.html > >> >> >> > > There are three thread related properties in server.xml . You > seem > >> >> to > >> >> >> have > >> >> >> > > run into maxThreads limit > >> >> >> > > Note that if your server cant handle the load that is a > server/OS > >> >> >> problem , > >> >> >> > > you are more likely to get help on a tomcat forum. Jmeter is > >> >> >> generating the > >> >> >> > > load correctly. > >> >> >> > > regards > >> >> >> > > deepak > >> >> >> > > > >> >> >> > > On Thu, Sep 10, 2009 at 9:38 PM, Mytho Logic < > >> >> >> [email protected] > >> >> >> > > >wrote: > >> >> >> > > > >> >> >> > > > Hi, > >> >> >> > > > > >> >> >> > > > I am using jmeter version 2.3.2. > >> >> >> > > > To test my application for 200 concurrent users I have used > >> >> >> distibuted > >> >> >> > > > testing set up. > >> >> >> > > > It works fine for 200 users. > >> >> >> > > > The test plan was - > >> >> >> > > > 1. 200 concurrent users will first hit the home page > >> >> >> > > > 2. After that 200 concurrent users will hit the products > page > >> >> >> > > > 3. After that 200 concurrent users will hit the product > Detail > >> >> page > >> >> >> > > > > >> >> >> > > > For concurrent user setup I have used 'Synchronizing Timer' > above > >> >> >> the > >> >> >> > > > thread > >> >> >> > > > groups and mentioned 200. > >> >> >> > > > It works fine and I got the result. > >> >> >> > > > > >> >> >> > > > Setup:- > >> >> >> > > > > >> >> >> > > > Tomcat server, Jmeter client and Jmeter server all are in 3 > >> >> >> different > >> >> >> > > > machine. > >> >> >> > > > > >> >> >> > > > Tomcat Server > >> >> >> > > > ------------- > >> >> >> > > > JAVA_OPTS=-Xms1024m -Xmx1024m > >> >> >> > > > > >> >> >> > > > Jmeter Client > >> >> >> > > > ------------- > >> >> >> > > > HEAP=-Xms512m -Xmx1024m > >> >> >> > > > > >> >> >> > > > Jmeter Server > >> >> >> > > > ------------- > >> >> >> > > > HEAP=-Xms512m -Xmx4096m > >> >> >> > > > > >> >> >> > > > Using the same configuration and same setup,when i tried > for 220 > >> >> >> > > concurrent > >> >> >> > > > users for few few sample requests I got > >> >> >> > > > "java.net.ConnectException: Connection refused: connect: > >> >> exception. > >> >> >> > > > Sometime I succeded for 220 concurrent users without any > >> >> errors.But > >> >> >> next > >> >> >> > > > time whne I again run the test plan for > >> >> >> > > > 220 concurrent users I got exception. > >> >> >> > > > > >> >> >> > > > What is the reason behind this exception and how can I solve > >> >> this? > >> >> >> > > > I need to load my application upto 500 concurrent users. > Please > >> >> >> suggesst > >> >> >> > > > how > >> >> >> > > > can I do this? > >> >> >> > > > > >> >> >> > > > This is an urgent requirement. > >> >> >> > > > > >> >> >> > > > Thanks > >> >> >> > > > Maumita > >> >> >> > > > > >> >> >> > > > >> >> >> > > >> >> >> > >> >> >> > --------------------------------------------------------------------- > >> >> >> 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] > >> > >> > > > > --------------------------------------------------------------------- > > 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]
