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rastech1's avatar
rastech1
Occasional Contributor
14 years ago

I need the exact values added in Average Process Time in Load Testing Analysis Page..

Hi,

I got a realy hard problem here while analysing my results. 

Still some values in the log result pages are not clear for me..For example Average Process Time in the Laod Testing Analysis Page,

 in the helps the statement for Avg.Process value in the Analysis log page is this

"Average virtual user life time (in seconds) during the test run."



In te Help page named "HTTP Load Testing - Timing Task Execution", all times in the log results page is defined but not his one..

I mean, I can not find same exact definitions for the Analysis page columns, especialy for average process time..



it is not mentioned anywhere, whether some other times included in it or not.

such as

test engine initializaiton time or Time needed to log the results



And my problem is related to this;



In my load tests, I always see "Response Time" values are very very low for any request, such as like 0.01., 0,02 0,03 seconds etc.



So, I am not sure Response Time corresponds to TTLB (Time To Transfer Last Byte) as told to me before, this is still also a big gap for me to analysis my test results.. Something must be wrong in thesedefiniton..



In order to be sure, I make a load test for 1user up to payment page with 17 request, (only aspx requests), again response time are very low



Avg. Process time 3.5 seconds, and it is much much bigger than the total of response times..



and When I sum up all time-taken values in the IIS logs this is smaller than Avg.Process Time (time-taken values in IIS logs is also decsribed as TTLB officialy)

These are the times for a test with 17 request which only consists of aspx pages.

OK, here is the results I get,



Avg. Process Time = 3.85 (in Analysis Page)

Sum of Process Time of Test Complete Logs = 0.3

Sum of time-taken values from IIS log = 1.473



Someone please tell me this situation ??



What else included it Avg.Process time and how can I calculate real value ? I mean which value I have to decrease from that Avg.process times ?



What I want to do is, when I have run some load tests, and a result analysis page, can I show somebody those Avg.Process times as real times taken by users ?



It seems , it is not possible to get real real time of test without parsing IIS logs ??

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  • rastech1's avatar
    rastech1
    Occasional Contributor
    14 years ago

    Ok, lets go Step by Step

    According to "Load Testing Analysis Page"

    Avg Process Time column stores the average virtual user life time 

    and According to the "HTTP Load Testing - Timing Task Execution"

    the life time of virtual users contains of three parts,as below

      

    1.    Load testing engine initialization time.

    2.      Time needed to simulate connections (see below).

    3.      Time needed to log results and calculate the summary.


    And The life time of a connection consists of the following components:


    1.      Load testing engine initialization time.

    2.      Connection initialization time (this time is shown in the Initialization Time (s) column of the Connections section of the Load Testing log page). 3.      Time needed to simulate requests and receive responses (see below).

    4.      Connection finalization time.

    5.      Time needed to log results.



    --> At this point, for 1 and 5 in connection times, arent they also included in first step in 1 and 3 ??

    ------------

    And lets cintunie from help it says that


    As you can see, the time taken by items 1, 2, 4 and 5 is the difference between the connection time and the sum of request's and response's times.


    -- > So here is my case again, for a typical test with 1 user and 17 request,



    Avg. Process Time = 3.85 (in Analysis Page)

    Sum of all ResponseTimes in the same test, = 0.3 (I dont mention request times, they are always 0)



    And when I want to calculate that difference in order to learn the time taken by items 1,2,4,5



    3.85 - 0.3 = 3.55



    So, thats it ?? You mean by test actulay 0.3 seconds and all 3.5 seconds spend for initialization and log writing ? Are you kidding..

  • AlexanderM's avatar
    AlexanderM
    Staff
    14 years ago

    Hello Rasim,





    You mean by test actulay 0.3 seconds and all 3.5 seconds spend for initialization and log writing ?


    Yes, you are correct with the calculations. This is the way the Load Testing engine currently works - the initialization and finalization phases may take quite some time.





    can I show somebody those Avg.Process times as real times taken by users ?


    The times shown by TestComplete cannot be used to predict the real page loading time in a web browser (at least, with acceptable accuracy). The only thing you can tell about the page loading time in a web browser, is that it cannot be shorter than the total of the "Request Execution Summary" column in the Connections grid for all requests that are needed to load a page (when the server is under the same load).





    When loading a web page, a web browser not only receives the server responses (like TestComplete does), it also parses the HTML code, renders the page, fires events, and executes client-side event handlers.





    So, what you are getting from TestComplete as the "Time needed to simulate requests and receive responses" value, is a characteristics of the server-side part's performance, which may be different from the client-side UI performance. Measuring the client-side UI performance is a different type of testing, not directly related to Load Testing, and the results will greatly depend on the web browser you are using on the client.





    So, in general, the numbers you are getting in the Load Testing logs, should be used for performance testing, but not as absolute values. They are relative to each other. You run a test several times with different scenarios (different VU number, different server settings, different web application versions, different web server hardware, etc.) and compare the times you got in the Test Logs with each other to understand how the server's performance depends on the usage scenario. For example, if the response time doubles when you increase the load by 50%, then, probably, it is not good, and you are approaching the server capacity limit in terms of simultaneously working users.