I have an application that started showing a lot of HTTP/971 error codes. Never had heard of these HTTP codes, looked online, didn't find anything.
Then I found in the UI that it referred to "Canceled". After some more searches, found a page in the documentation, in that these errors are specific to Dynatrace RUM 🙂
They are the following:
They can be configured to not affect Apdex, which they do by default in Applications created after version 1.238
As always, I also got this exotic. Does anyone know some undocumented JS agent flags like cux = 0 that could help in this case and remove this status codes from application\affecting application?
Customer faced with problem that these JS codes impact on customer "best frontend code ever".
I have already removed this rule, but it didn't help. Customers code works only without JS agent loaded on page. Problem related to file uploading when agent is injected and customer code look like works without "No response" http codes.
Customer wan't change his "very good code" because it's insanely expensive.
I have already checked behavior with extended log of JS agent loaded on page. Already checked all information from support archive and HAR sessions of problematic behavior.
Also - I have tried to exclude this page with injection rule. It also didn't help
Then you should open support ticket for that. Most likely the application is written in a way that including the RUM breaks it. The 97x errors are just the effect of the application itself not working.
I'd not recommend turning off the capture of 97x errors.