Collect metrics in EPP for unsuccessful deliveries with active Jetstream backend

[k15r]

Motivation

In our event publisher proxy we only return HTTP 204 for successful deliveries with the jetstream backend and HTTP 503 for every error case. Metrics only get recorded for successful deliveries (204). In order to implement proper SLA tracking we need to record metrics also for unsuccessful deliveries.

Description

• return more specific HTTP codes based on the errors returned from Jetstream (see: https://github.com/nats-io/nats.go/blob/main/jserrors.go)
• record metrics for every request to the event publisher proxy with the backend set to jetstream.

  eventing_epp_messaging_server_latency_duration_milliseconds
  epp_event_type_published_total
  eventing_epp_requests_total
  

Hints

kyma/components/event-publisher-proxy/pkg/handler/handler.go

Line 303 in d232ed7

func (h *Handler) sendEventAndRecordMetrics(ctx context.Context, event *cev2event.Event, host string, header http.Header) (sender.PublishResult, error) {

exits early if a publishing requests fails on Jetstream. In order to implement the requested change we need to record the metric also in case of an error.

Attachments
Original Issue: #15936