Behavior of "specific number of times" rule setting

[Marcin]

Hello,

Pretty new to Fiddler, I'm using Fiddler Everywhere 5.21.0 .

What I'm trying to achieve is to replace the status code of a call to an identity server with 401, but just once.

I've created a following rule

Conditions:

When any of these conditions are met specific number of times: 1

URL Contains [Identity Server]/connect/token

 

Actions:

Update status code: 401

 

However, live traffic shows that when a /connect/token request is sent out, its status code is 200.

Only when I increase

When any of these conditions are met specific number of times: 2

A /connect/token request (a singular one, based on the Live Traffic view) will have its status code replaced to 401.

Why is that the case? Does the Live View actually filter out some traffic?

 

Thanks for bearing with my silly questions.

[Zhivko]

Hello Marcin,

Thank you for reporting that issue. Actually it appeared to be a bug on our side. We are currently working on some changes to the rules for our next release that will fix the faulty behaviour. As a temporary workaround, you can add a match condition Status code is not 401. This will resolve the issue. The reason it only works when you set it to 2 is that we match the same session twice (once we receive the request from the client and once the server returns a response. The workaround fixes it by only matching when we receive the response, not on the request).

The live traffic view will not filter any traffic by default, it only filters based on your applied filters and rules.

Hopefully, our next release will make the rules much easier and clearer.

Regards, Zhivko Progress Telerik

[Marcin]

Hi Zhivko,

Thanks for explaining the process - actually it does now make sense. I'd even be alright with this behaviour if it was communicated a bit clearer. Nevertheless, your workaround does work perfectly - many thanks! :D Looking forward to the next release.

Best,

Marcin