Alleluia !! a Load Test tool for Silverlight 4 that gives results within 5 min ! {download, install and running the tests included}

After many searches, having read many people complaining about Load testing a Silverlight applications, watching nice demo of "Hello World" cases, installed commercial tools {but was stuck at some configuration points. See the notes at the end where I listed some of my tests}, and I finally …. gave up tonight !!



But thanks to a final search on Fiddler2 fields {because it gave me the most promising results}, I came across stresstimulus tool. So sorry for those of you who already know this free Fiddler add-on, and also may be its limitations {in which case, please tell us your view points}.

For the purists, I don't want to test Silverlight UI as such {i.e. for this type of test, I am not interested in Visual Studio 2010 Coded UI}, since it runs Client-side. Rather, I wanted to validate that, once deployed into production, this RIA will not put our IIS servers down. Hence, I want to simulate the load on Server-side, by generating lots of various calls to our web services easily.

For my first trial of this tools, I chose a complex Line Of Business application
{ Disclaimer for those who recognizes this application /!\ I just did it gently so that I do not break it}.




Within the next 5 min I got the detailed results !! I could have nearly cried so much it was easy and … cheap !! {I am moving to the Pro version since I checked that it works fine on our real application, even with STS WIF and WCF binary activated !! which seams to be so difficult to handle for other tools}.






Here are some results
Performance Graphs: Number of simultaneous users, request per seconds, Average response time, Bytes received per seconds, Errors per seconds.


A summary page: 

Test Summary Test Case Summary File Name: Thavonekham-Tests.ssconfig Primary Pages: 2 URLs : 39

Test Parameters Think time between base pages: As recorded Iteration timing: Think time between iterations - 2s Load pattern: Constant load Users: 5 Browser Type: IE8 Network Type: Dial-Up 56k Complete test after: 5 iterations Warm-up time: 0 seconds Test Run Information Date: Oct-1 2011 Start Time: 21:46:34.19 End Time: 21:48:00.11 Warm-up (s): 0 Aggregate Session time (s): 851.53 Test run duration (s): 85.92

Overall Result Status: Completed Max User Load: 5 Total bytes sent: 138,960 Total bytes received: 41,191,492 Bytes sent/sec: 1,617.292 Bytes received/sec: 479,409.064 Errors Http Errors: 0 Total Timeouts: 0 Page Timeouts: 0 Missed Goals: 0 Test Iterations Iterations Started: 5 Iterations Completed: 5 Avg. iteration time (s): 78.76 Requests (HTTP transactions) Total requests: 195 Requests/sec: 2.27 Avg. response time (s): 4.37

Page detailed {in terms of *.aspx for instance}: 



Request details {including resources such as xaml, png, xap, svc, …}


And finally
Iteration Details



And it does really stress my Windows 8 computer ! {I only ran the test below for 30 seconds}


At least one limitation: The generated reports do not track down to a specific WebMethod…. except on the example above. Indeed, the calls to WebMethods were passed within the Query String.


Monitoring the load on the Database:
As a complementary tool, use Microsoft SQL Server Profiler {in profiling mode, with a filter set to the name of your database to filter out unwanted SQL queries}. When you play back your tests with StresStimulus, it does call my Web services WCF bin and generated large amount of hits on the database. Now, just spot your top slower queries, and here you go ! Optionally, you could save your trace and run SQL Tuning Advisor.

HOWEVER it is NOT a win yet, I have to try on our real life project. Indeed, I love Silverlight it is just a great RIA, but I also I apply even more the proverb “A bird in the hand is worth two in the bush”.
Finally, it seams that with Silverlight we are left behind within the .Net world {eg. Unit Testing, CodeCoverage, proper ALM, …}

If you find better tools, please let me know.




TIPS / IDEAS / Alternative solutions for testing SL apps|: 

• http://www.infoq.com/articles/Silverlight-Load-Testing
• http://www.astaticstate.com/2010/06/silverlight-ria-services-load-and.html
• http://blog.dynatrace.com/2011/09/28/to-load-test-or-not-to-load-test-that-is-not-the-question 
• http://social.msdn.microsoft.com/Forums/en/vstswebtest/thread/417bdf50-fef7-4035-811a-050998ee370d 
• http://blogs.codes-sources.com/thavo/archive/2011/10/01/sl4-alleluia-enfin-un-outil-de-load-test-pour-silverlight-4-qui-marche-en-5-min-download-install-et-execution-compris.aspx
• Great and Free account, based on AZURE http://www.cloudnetcare.com

NB : If you want to know what other tools I tried "{ and start to feel the pain I went through}  see below:

Re: Load Testing vis Silverlight Client? 1 hour, 16 minutes ago | LINK Hi, I also struggled finding a proper load testing tool for Silverlight 4 {I know plenty of smart people would claim that there is no need to test RIA, but I want to test the WCF that my SL is using} : Plenty of "Hello World" nice and sunny video, ... but the reality is so different. 1> Despite the fact I was using VS 2010 ultimate, it seams not to work "out of the box" for SL ! {despite its price} 2> I successfully used Fiddler2 {free of charge} to record aspx calls, and most importantly the binary WCF calls { svc}. Fiddler2 offers the surprising ability to "SAVE AS VISUAL STUDIO WEB TEST" [Visual Studio WebTest http://www.fiddler2.com/fiddler/help/WebTest.asp]. The only problem I had is that VS 2010 did not understand the binary messages that was recorded ! Damned !! I guess I unfortunately have to add an plain text endpoint. That was my most promising experience in Load testing with SL. 3> Otherwise you can find at least 2 CodePlex projects {http://wcfloadtest.codeplex.com/ and http://teamtestplugins.codeplex.com/}. that seams to be OK, but they are not really maintained. My first go with those tools did not succeed all the way through. only partially. 4> It seams HP Loadrunner 11 supports Silverlight 3 and 4 with WCF bin mode {but not advanced bindings, which is fine with me}. I will try that in the following months {just the time for me to sort out the license and first install}. 5> Selenium Silverlight http://code.google.com/p/silverlight-selenium/updates/list and www.neotys.com If you are more lucky with EASY tools {i.e. I know my VS 2010 would work with plenty of cheats and "CodePlexes" }, please HEEELLLLPPPPP !! UPDATE > alleluia I just tried a Free {but with limited Virutal Users} add on to the great Fiddler2 beta. It is stresstimulus > Follow the link here http://memoprojects.blogspot.com/2011/10/alleluia-load-test-tool-for-silverlight.html. Vincent THAVONEKHAM. SL4LoadTest@thavo.com www.thavo.com

( Vincent THAVONEKHAM, Team Foundation Server 2010 Trainer - ALM with TFS 2010 and Scrum - Paris. www.Thavo.com )