topic Re: Service settings - HTTP error detection in Real User Monitoring

Service settings - HTTP error detection

josef_solnicky — Mon, 26 Apr 2021 10:41:34 GMT

In customer application there are sometime coming HTTP 431 errors "Request Header Fields Too Large". Developers would like to get alert when it happens.

I was trying to add it to server side response code definition in service HTTP error detection - see attached screenshot, but nothing happened. From documentation it is even not clear how the syntax should look like.

Any experience with it ?

Re: Service settings - HTTP error detection

Enrico_F — Wed, 04 Nov 2020 09:18:46 GMT

IMO there should be no need to add the 431 response code as shown in the screenshot as Dynatrace will already mark such requests as failed by default unless you have configured related exceptions under "Ignore exceptions".

I suspect your problem is rather with choosing the right anomaly detection settings for the responsible service so that problems are detected and notifications sent (if configured). In particular make sure you understand the implications of the settings in section "Detect increases in failure rate":

HTH

Enrico

Re: Service settings - HTTP error detection

josef_solnicky — Thu, 05 Nov 2020 09:49:20 GMT

Thank you Enrico,

I feel/understand from https://www.dynatrace.com/news/blog/improved-failure-detection-functional-errors-based-request-attributes/ - the Dynatrace is alerting only server side errors (first box in alert detection). Then I am trying to add "431" there.

@Michael K. - can you please comment it ? BR, Josef