I’ve seen this error in our logs:

HTTP parse error, malformed request (): #<Puma::HttpParserError: HTTP element REQUEST_PATH is longer than the 2048 allowed length (was 2459)>

I understand busting the 2048 limit is not very smart, but I think we should be able to catch those somehow. I did configure lowlevel_error_handler but this only catches errors from the Rack stack.

Currently the only solution I can think of is adding a Logentries alert matching Puma::HttpParserError. Would be better than nothing, yet I’d rather have those errors sent to Rollbar instead.

Is there any way to have those parser-level errors caught in Ruby land and reported to exception trackers?

If not, are there many other unlikely-yet-possible parser-level errors apart from REQUEST_PATH max length? Would it be wise to write them all somewhere in the Puma doc, or at least point to some files in the Puma .c/.java source where there are all located? Or as a last resort, suggest using a log-based monitoring solution like I described above?