sounds like there is a memory leak some where. generally speaking, if a webapp is well written, the memory percent should should a regular pattern. I generally prefer to have the memory percent below 60%.
based on your description, it sounds like the application is either memory hungry, or it may have a slow leak. Your conclusion is correct. At this point, using a profiler is the only way to track the problem down. the monitor is very basic and simple, so it won't help diagnose memory leaks. I mainly use borland optimizeIt to profile tomcat and have had good luck with it. I hear yourkit is also a good product. good luck peter On 7/21/06, Andy Dawson <[EMAIL PROTECTED]> wrote:
Hi Peter, As always thanks for your reply. I assumed there was a good reason for the choice - I did google before posing the question, is there a more appropriate search that might prevent (my) duplicate questions? My more detailed search just now pulled up your blog on the topic. The application that I am load testing keeps dropping out unexpectedly over time, I was finding that a reported memory % that continually bounces around 90% from beginning to the end of a test with steadily increasing number of threads (end being when the server stops responding), didn´t tell me what I expected, hence the change to my local set up. I deduce I should investigate using a profiler rather than tweaking the monitor and getting (potentially) erroneous or misleading results (due to local changes). Thanks & regards, Andy Peter Lin wrote: > The reason for using (total - free)/total is that max value is not > accurate. > the only cases where max is more useful is if someone wants to know how > close to Max they are and they've set an explicit Max heap. > > other people have asked about this in the past. For example, on linux or > solaris, if one were to use top to see the memory used by tomcat, > often it > won't match the max value. Therefore it's not accurate and doesn't really > help. > > tomcat could crash before ever reaching the max. Most of the cases > where I > see servlet container crash is a sudden spike, which ends up looking > like a > spike in jmeter tomcat monitor. hopefully that explains the rationale > behind using (total - free)/total > > peter > > > > On 7/20/06, Andy Dawson <[EMAIL PROTECTED]> wrote: >> >> Hi All, >> >> I have a simple jsp application I am currently testing and Tomcat is >> installed with all the defaults. After noticing that the memory load was >> always above 50% according to JMeter I wondered if this was reporting >> what I was expecting. >> >> With the defaults, and for low/no load, the server reports something >> like: >> Free Memory: 13300000 >> Total Memory: 32000000 >> Max Memory: 66600000 >> >> The documentation implies, as is clear from the code, that the memory >> load percentage is calculated as >> Load = (Total - Free)/Total >> >> I was expecting it to be: >> Load = (Total - Free)/Max >> >> Do I understand correctly the intended meaning of server Memory Load? >> >> Thanks in advance, Regards, >> >> Andy >> PS. I´ve already changed the code in my install to do the above. >> Ref: >> http://jakarta.apache.org/jmeter/usermanual/build-monitor-test-plan.html >> >> >> --------------------------------------------------------------------- >> 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]
