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VS Load testing for Services:- Test mix percentage based on Virtual users RRS feed

  • Question

  • I am doing load test for services. I have three test methods to target in the load with 600 users each.

    I have set up the load test with Test mix percentage based on Virtual users mode. And in the constant load pattern, constant user count I put 1800, Assuming that the three tests share about 600 virtual users.

    But when I ran the test the test aborted with that many user. If I use 600 user and run one test at a time, it works. but I wanted to set up and run the tests all together rather than doing individually one at time.

    Can any body help on this?

    One more question, When I use lets say 600 users , constant load pattern setting,  Does it mean 600 concurrent users? that is my understanding,  is that right?

    Thank you!!

    Abi

    Thursday, September 15, 2016 5:34 PM

Answers

  • Hi ABi21,

    According to the error message which indicates the required performance of the load test exceeds performance of the machine itself. This situation could result in OOM exception.

    According to your description, the test run successfully with 600 v-users for one test but 1800 v-users for three tests. Although you have set the distribution of 1800 v-users, but during the test time, the machine need to do the test for 1800 v-users completely. And if you test one method with 600 v-users in one time. The former performance pressure is greater than the second.

    Based on the number of v-users mode is to determines the percentage of virtual users who will run a particular Web performance or unit test. At any point in the load test, the number of users who are running a particular test matches the assigned distribution. Use this test mix model when you are basing the test mix on the percentage of users who are running a particular test.

    Please refer to the following MSDN document:

    https://msdn.microsoft.com/en-us/library/bb514186(v=vs.120).aspx#PercentageBasedonVirtualUsers

    Sincerely,

    Oscar


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    Friday, September 16, 2016 6:02 AM
    Moderator

All replies

  • 1800 users is quite high for one computer to support. With that load I would consider using 2 or 3 or even  4 agent computers. You say that a test with 600 users works. What do the graphs of CPU percentage and of memory usage show when that test runs? Is there enough spare to handle three times the load?

    You said that the test with 1800 users aborted. What error messages were produced? Why did the test abort? When did it happen? How long did the test run before it aborted? What did the graphs show? If the test aborted very quickly and there are no load test graphs then run task manager (with fast updates selected) or Perfmon to monitor CPU and memory of the computer running the tests. Then rerun the test and see what the graphs show.

    You could also try running with other smaller numbers of users to try and understand more about why the test aborted and how to continue.

    Regards

    Adrian

    Thursday, September 15, 2016 8:31 PM
  • Thanks Adrian for the explanation!!

    I got  "Unable to start load test thread: Exception of type 'System.OutOfMemoryException' was thrown" with 1800 users.

    But What makes me confuse is that  I have three test methods and the 1800 users divided for these three test method calls with each about 600 users as I am using Test mix percentage based on Virtual users mode. Is my understanding correct? or can you explain how the distribution works with Test mix percentage based on Virtual users mode.

    Thanks!

    Abi

    Thursday, September 15, 2016 10:49 PM
  • Hi ABi21,

    According to the error message which indicates the required performance of the load test exceeds performance of the machine itself. This situation could result in OOM exception.

    According to your description, the test run successfully with 600 v-users for one test but 1800 v-users for three tests. Although you have set the distribution of 1800 v-users, but during the test time, the machine need to do the test for 1800 v-users completely. And if you test one method with 600 v-users in one time. The former performance pressure is greater than the second.

    Based on the number of v-users mode is to determines the percentage of virtual users who will run a particular Web performance or unit test. At any point in the load test, the number of users who are running a particular test matches the assigned distribution. Use this test mix model when you are basing the test mix on the percentage of users who are running a particular test.

    Please refer to the following MSDN document:

    https://msdn.microsoft.com/en-us/library/bb514186(v=vs.120).aspx#PercentageBasedonVirtualUsers

    Sincerely,

    Oscar


    We are trying to better understand customer views on social support experience, so your participation in this interview project would be greatly appreciated if you have time. Thanks for helping make community forums a great place. Click HERE to participate the survey.

    Friday, September 16, 2016 6:02 AM
    Moderator
  • Hi ABi21,

    Have the above replies help you resolved the issue? If yes, please mark them as answer, if not, please feel free to let me know your latest results. Thank you very much.

    Have a nice day :).

    Sincerely,

    Oscar


    We are trying to better understand customer views on social support experience, so your participation in this interview project would be greatly appreciated if you have time. Thanks for helping make community forums a great place. Click HERE to participate the survey.

    Tuesday, September 20, 2016 8:48 AM
    Moderator