This apache module counts the result status of each request handled by apache httpd. The counters can be fetched via a module_hablder wicht outputs prometheus text output if you use query param prometheus. This is handy to do some monitoring.
To use compile with apxs, add a location handler an LoadModule directive to your config:
LoadModule result_status_counter_module modules/mod_result_status_counter.so
<Location /mrsc>
SetHandler request_status_counter
</Location>
~ curl http://localhost/mrsc
# HELP http_requests_count_total The total number of HTTP requests.
# TYPE http_requests_count_total counter
http_requests_count_total{status="100 Continue"} 0
http_requests_count_total{status="101 Switching Protocols"} 0
http_requests_count_total{status="102 Processing"} 0
http_requests_count_total{status="200 OK"} 11
...
FIXME: I could not find a way to translate the apache result-array indices back to status codes and sadly status_lines is not exortet in http_protocol.h so for now in copy&pasted the definition of status_lines[]