When server authentication is used, some test cases may require users that have certain permissions. Therefore there is a need to map certain VUs' credentials to certain test cases. In StresStimulus, this is implemented using User Groups. Every VU credential is assigned to a user group, and every test case runs with a selected user group. Here is how to use these user group:

  1. In the Authentication section, input all the credentials.
  2. Set the Show user group column? to Yes (a), and the User Group column (b) appears in the authentication grid.
  3. In each credential record, write in the group name that the record will belong to.

  4. In the Managing Test Case section, select a test case (or test case group) and set the User Group property to the group name that this Test Case will use.

VU to credentials mapping 

By default, every new VU will be mapped to a row of that VU's number. So VU1 → row 1, VU2 → row 2, ... VU10 → row 10, etc...

If the number of VUs exceeds the number of credentials, then they are assigned using a round-robin algorithm. For example, if you have 10 rows in the Authentication grid and emulate 20 VUs, then VU1 and VU11 → row 1, VU2 and VU12 → row 2, etc...

Imagine a test with 2 test cases (TCA and TCB), and each test case uses a different User Group. Since VUs are distributed between TCA and TCB in an unpredictable order, there may be VUs mapped to the same credentials row and some other credential rows not mapped to any VU.

In order to fix this problem set the VU-to-row mapping property to On-Demand

This will assign credential rows to VUs on a first-come basis. Since the rows are assigned on-demand, there is no way to tell ahead of time which credential row will be assigned to which VU.

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