how to set alarm on tracing for endpoint with err response code?

[houbinglei]

i have set endpoint oal metric:
endpoint_err_count = from(Endpoint.*).filter(httpResponseStatusCode in [400, 404, 500, 503]).count();

and i can get alert when /voiceBot/api... return 404;
but how can i get alert when /rest/v2... return 404 and /voiceBot/api... return200?

[wu-sheng]

Alerting is only for metrics, not trace or log. If you want to set alerting, try to use OAL to extract metrics from traces.

[houbinglei]

Thanks very much for your detailed explanations!
i have tried this oal metric:
endpoint_err_count = from(Endpoint.*).filter(name in ["/rest/v2..."]).count();

but i get the result with null;

how could i use OAL to extract metrics from traces?

[wu-sheng]

Check the endpoint page to get the endpoint name correctly.
Don't guess.