Question

I’m using WCAT to load test my app, and I want to see the traffic in fiddler.

When I run the WCAT script, it runs OK,but I don’t see any of the traffic in fiddler… Do I need to configure fiddler to proxy WCAT traffic?

The web app I am testing is on my local machine, but I’m not addressing it with “localhost”, I’m using the name of my machine in my settings config. I don’t have any filters set up in fiddler either.

EDIT:

Here’s my transaction I’m testing with (the ipv4.fiddler is a recent addition as per a suggestion below):

transaction
{
    id = "add a new user";
    weight = 1;

    request
    {
            verb = POST;
            postdata = "Name=Bob+Smith&Gender=M&DateOfBirth=01%2F01%2F1970&Email=testuserdude" + rand("1","1000") + rand("1","1000") + "@example.com&Password=123456&ConfirmPassword=123456";
        url         = "http://ipv4.fiddler/TokenBasedLoginTests/Account/Register";
        statuscode  = 302;
    }
    close
    {
        method      = ka;
    }
 }

Thanks

Matt

Answer 1

Per http://blogs.iis.net/thomad/archive/2010/05/11/using-the-wcat-fiddler-extension-for-web-server-performance-tests.aspx,

WCAT requests won’t show up in Fiddler
nor can a proxy server be used with
WCAT.

The former part of that statement is implied by the latter part. It suggests that the WCAT team specifically removed the ability to use a proxy server, which seems like an odd choice, but might make sense if they thought the load would take down a proxy.

If you wanted, you could configure Fiddler to run as a reverse proxy, and then point WCAT at that reverse proxy; you’d see the traffic then, and Fiddler would redirect inbound requests to their actual destination. See http://www.fiddler2.com/redir/?id=reverseproxy

You might consider using the Visual Studio Web Test tools instead, as they do properly use the proxy (and hence Fiddler).