Question

I am new on Load Testing (and in general, testing) with visual studio 2010 and I am dealing with several problems.

My question is, is there any way possible, to add a custom test variable on the Load Test Results?

I have the following UnitTest:

[TestMethod]
public void Test()
{
    Stopwatch testTimer = new Stopwatch();
    testTimer.Start();
    httpClient.SendRequest();
    testTimer.Stop();

    double requestDelay = testTimer.Elapsed.TotalSeconds;
}

This UnitTest is used by many LoadTests and I want to add the requestDelay variable to the Load Test Result so I can get Min, Max and Avg values like all others Load Test Counters (e.g. Test Response Time).

Is that possible?

Answer 1

Using the link from the @Pritam Karmakar comment and the walkthroughs at the end of my post I finally managed to find a solution.

First I created a Load Test Plug-In and used the LoadTestStarting Event to create my Custom Counter Category and add to it all my counters:

void m_loadTest_LoadTestStarting(object sender, System.EventArgs e)
{        
    // Delete the category if already exists   
    if (PerformanceCounterCategory.Exists("CustomCounterSet"))
    {
        PerformanceCounterCategory.Delete("CustomCounterSet");
    }

    //Create the Counters collection and add my custom counters 
    CounterCreationDataCollection counters = new CounterCreationDataCollection();
    counters.Add(new CounterCreationData(Counters.RequestDelayTime.ToString(), "Keeps the actual request delay time", PerformanceCounterType.AverageCount64));
    // .... Add the rest counters

    // Create the custom counter category
    PerformanceCounterCategory.Create("CustomCounterSet", "Custom Performance Counters", PerformanceCounterCategoryType.MultiInstance, counters);
}

Then, in the LoadTest editor I right-clicked on the Agent CounterSet and selected Add Counters… In the Pick Performance Counters window I chose my performance category and add my counters to the CounterSet so the Load Test will gather their data:

Finally, every UnitTest creates instances of the Counters in the ClassInitialize method and then it updates the counters at the proper step:

[TestClass]
public class UnitTest1
{
    PerformanceCounter RequestDelayTime;

    [ClassInitialize]
    public static void ClassInitialize(TestContext TestContext)
    {
        // Create the instances of the counters for the current test
        RequestDelaytime = new PerformanceCounter("CustomCounterSet", "RequestDelayTime", "UnitTest1", false));
        // .... Add the rest counters instances
    }

    [TestCleanup]
    public void CleanUp()
    {
        RequestDelayTime.RawValue = 0;
        RequestDelayTime.EndInit();
        RequestDelayTime.RemoveInstance();
        RequestDelayTime.Dispose();
    }

    [TestMethod]
    public void TestMethod1()
    {
         // ... Testing
         // update counters
         RequestDelayTime.Incerement(time);
         // ... Continue Testing
    }
}

Links:

• Creating Performance Counters Programmatically
• Setting Performance Counters
• Including unit test variable values in load test results