How to run load test Scenario once every hour? - visual-studio

Question

I have a loadTest with several scenarios, running for 12 hours.
I want to add another scenario, that will run once a hour, by 10 virtual users.
The ugly solution I'm using is to have 12 additional scenarios, each one has its own "delayed start", with 1 hour interval.
This is an ugly solution.
How can I tell a specific scenario to run once a hour.
Note: For this case I don't need it to run sharp each hour. The main idea is to have a task that run +/- every hour.

Answer 1

I suggest having a load test with two scenarios, one for the main user load, the other for the hourly 10-user case. Then arrange that the number of virtual users (VUs) for the 10-user is set to 10 at the start of every hour and reduced as appropriate. The question does not state how long the 10-user tests runs each hour.
The basic way of achieving this is to modify m_loadTest.Scenarios[N].CurrentLoad, for a suitable N, in a load test heartbeat plugin. The heartbeat is called, as it name suggests, frequently during the test. So arrange that it checks the run time of the test and at the start of each hour assign m_loadTest.Scenarios[N].CurrentLoad = 10 and a short time later set it back to 0 (i.e. zero). I believe that setting the value to a smaller value than its previous value allows the individual test executions by a VU to run to their natural end but the VUs will not start new tests that would exceed the value.
The plugin code then could look similar to the following (untested):
public class TenUserLoadtPlugin : ILoadTestPlugin
{
const int durationOf10UserTestInSeconds = ...; // Not specified in question.
const int scenarioNumber = ...; // Experiment to determine this.
public void Initialize(LoadTest loadTest)
{
m_loadTest = loadTest;
// Register to listen for the heartbeat event
loadTest.Heartbeat += new EventHandler<HeartbeatEventArgs>(loadTest_Heartbeat);
}
void loadTest_Heartbeat(object sender, HeartbeatEventArgs e)
{
int secondsWithinCurrentHour = e.ElapsedSeconds % (60*60);
int loadWanted = secondsWithinCurrentHour > durationOf10UserTestInSeconds ? 0 : 10;
m_loadTest.Scenarios[scenarioNumber].CurrentLoad = loadWanted;
}
LoadTest m_loadTest;
}
There are several web pages about variations on this topic. Searching for terms such as "Visual Studio custom load patterns". See this page for one example.