Description
Opening a separate issue for the HTTP part of #79371, also including requests from #79459. We should eventually implement the Metrics counterpart of all System.Net.Http EventCounters.
Implemented as part of #84978
requests-failed,current-requestshttp(11|20|30)-connections-current-total
Note that Metrics variants of requests-failed, current-requests will be semantically different from EventCounters since we need to comply with the OTel specification which wants us to record the counters until "headers receieved" and exclude response buffering in case HttpCompletionOption.ResponseContentRead is passed. See the discussion in open-telemetry/opentelemetry-specification#3520.
Event counters not discussed in #84978
requests-startedrequests-started-raterequests-failed-ratehttp(11|20|30)-requests-queue-duration
Additional requests from #79459; we don't have existing counters for these
- number of idle connections
- average idle connection time
- number of connections evicted from pool due to idle timeout
- number of connection timeouts
- average time to connect
- queue length
- number of http 2 keep alive pings which didn't receive a response
- average response time of http 2 keep alive pings
Regarding tags, there is a wish in #79459:
Ideally these metrics would be available per FQDN:Port combination, broken down by type (i.e. HTTP1.1/HTTP2) and there would be some way to track which http client each pool belongs to.