Month: June 2013

I’ll be honest, I’m surprised at how quickly this has come together. I didn’t even know if I could make it work when I began, and I’ve managed to fit it in with doing full time performance testing and living life as an international contractor.

It’s not “finished” but then nothing ever really is in AutomationSolutions-world. There is scope to extend beyond the 15 or 16 runs it currently caters for. I can make that ticker a bit less intrusive too I expect. But the fact is that it works… and it works rather well.

It’s not the prettiest spreadsheet in the world, and there are other features I’d like to add to allow for user configuration. But they’re my changes. You’re going to have to ask nicely for them. Or you can use v1.0, the basic scheduler. Which is provided here:

LR_Batch_Scheduler

It’s taken a little over a week to build that and roll it out in Belgium, we’re using it this evening for the next cycle of tests. If there’s no update on this following that, you’d be safe to assume that it works as reliably as I think it does.

I hope it’s usage is fairly self-explanatory since I haven’t prepared any sort of documentation yet, and I’m not likely to unless someone screams.

From the previous post, it should be possible to see that the next_tick function which counts the time is our trigger for execution.
Specifically this loop and if combination:

For i = 0 To UBound(ArrTimes)
If [A1].Value = ArrTimes(i) Then
Application.StatusBar = "Running test id: " & Range("A" & i + 6).Value

End If
Next i


Since I first wrote that last week, I’ve added a field to state that a run has been “done”. And I’ve built in a little tolerance by checking if the current time is greater than the execution start time – stored as ArrTime(n).

I’ve also borrowed some code from VBA Express to terminate a running process. Now I’m not terminating the process, I’m just checking if WLRun.exe aka the controller is running.

So the latest code looks like this:

For i = 0 To UBound(ArrTimes)
If [A1].Value >= ArrTimes(i) And Range("F" & i + 6) <> "DONE" Then

End If
Next i


I’ve just replaced the existing section with that, but I’ll post the full deliverable at some point (when it’s finished 🙂 )

I’ve also defined the module to call the controller.

Sub StartTest(Scenario_Path, Results_Path)

End Sub

At the moment it just message_boxes the command string for testing purposes.

So now, we have:

A time-based system within Excel which will run a defined scenario at the appropriate time. I haven’t figured out yet what I’d like to do if WLRun is still running, but it’s coming together and I think that’s the last thing. I think I’ll add a minute on to all future runs to delay the system.

I also added an autoschedule function, mostly for testing purposes. I’ll document that in a future post, it’s not really important.

I’ve made a start on the Loadrunner Batch Scheduler – There is still a long long way to go, but the basis of the underlying code and the basic design is done, I guess.

The Dashboard

The Code

The code below implements a timer – showing the current time in cell A1.

Pushing the start button fires StartBtn_Click, which reads our run variables into an array, and starts the timer.
StopBtn_Click stops the timer.
Then there is next_tick which checks our array of times against the current time. If it takes longer than a second to parse the array I suppose it’s possible to not fire the code, but I’m only allowing for 14 runs at the moment.

I’ll look to build 10 seconds of tolerance into it at some point, but then it will need to know that it’s executed on the 1st second so as not to try to fire on the 9 subsequent ones. (A “done” flag essentially).


Dim ArrTimes(14)

I should add by way of a disclaimer, I have absolutely no idea if this is going to work at all, let alone reliably, at this point. But It’s a promising start in my opinion. Oh, and I do indent my code in the IDE, but WordPress or this theme, wipe that out. My code is pretty, honestly.

So, following on from the previous article / rant…

I managed to re-build the excel spreadsheet & macro functionality within VB6. I’d provide more details but it’s largely bespoke and unlikely to aid anyone, including me, in the future.

The app makes a call to openssl in order to generate, encrypt and/or decrypt a user certificate.
It’s all called from the command line, and that was interesting to build and a pain to test.

In any case, for reference, to build an application in VB6 without any forms:

Go to project properties (for the entire project, not just a module) and select startup object as a sub – in my case SUB MAIN.

Define SUB MAIN as a standard module and either call all your code within it, or add you code within it directly.


Public Sub Main()

End Sub


Testing is a pain because once you’ve made the executable, it only accepts the command line variables passed in (sArgs). So you end up putting a duplicated call in with hard-coded values – like the above.
And then you forget, make the executable and run it. It works – of course – because it’s using the hard coded variables.
And then you have to fire up the IDE, fix it, recompile, rebuild and retest.

And if you’re using loadrunner and the system command to test this, it can take a while:

The call:

strcpy(commandstring, lr_eval_string("C:\\Matt\\TestStubATE{vUserID}.exe "));
strcat(commandstring, lr_eval_string(" {sessionId}"));
strcat(commandstring, lr_eval_string(" {randomSalt}"));
strcat(commandstring, lr_eval_string(" {path_to_certificate}"));
strcat(commandstring, lr_eval_string(" {IngID}"));

rc = system(commandstring);


This particular script uses a certificate generated by OpenSSL from Loadrunner. Only the certificate was missing a newline / carriage return, line feed. Easy enough to fix in code I thought. Well in C in Loadrunner it was a pain – seriously I spend half my life battling with string manipulations in C, why isn’t there a mid function, an instring, a substring function etc? And don’t get me started with StrTok.
So I built that in VBS:


Const ForReading=1
Const ForWriting=2

It looks for a line with DEK-Info on it and appends a new line onto it.
LR calls that in much the same way:

strcpy(commandstring, "C:\\Matt\\TestStub_Repo\\EditPemFile.vbs ");
strcat(commandstring, buffer);
system(commandstring);


Buffer contains the path to the certificate file.

So 2 test stubs to workaround issues identified, no great problem there. Except the vb6 one is an executable, and I have no idea how threadsafe or reliable that’s going to be. It’s command line only so the memory and cpu footprint is minimal but better safe than sorry. Especially when performance testing so I created another VBS to copy the teststubAte executable and rename it an teststubAteN.exe where N will represent the vUser ID within the injector.
I find out tomorrow if that works when my POC for this project is built.

Is it sad that I’ve enjoyed the complexity of all this? It’s not. Is it going to be annoying when someone tells me it was all unnecessary, that I could have done it another better way. Well, yes, it will be. IF it happens.