Prometheus is an open-source monitoring system that collects metrics by scraping HTTP endpoints at regular intervals. Deploy this element on a dedicated endpoint to expose Membrane's internal metrics in the Prometheus text exposition format (v0.0.4).

Metrics reported (all prefixed membrane_):

count / good_count / good_time / good_bytes_req_body / good_bytes_res_body — request counters and totals per proxy, labeled by HTTP status code range.
rule_active — whether a proxy is active (1) or inactive (0).
ssl_haskeyandcert / ssl_validfrom_ms / ssl_validuntil_ms — TLS certificate presence and validity window in Unix milliseconds.
openapi_validation — validation pass/fail counts, present on api proxies with an OpenAPI validator configured.
lb_node_status{node,cluster} — load balancer node health (1 = UP, 0 = DOWN).
Response time histograms per proxy and status code range.

See examples/monitoring-tracing/prometheus-grafana for a runnable demo including Grafana dashboards.

Example Configuration

api:
   port: 2000
   flow:
     - prometheus: {}

api:
   port: 2000
   flow:
     - prometheus: {}

Syntax

prometheus:
  buckets: <string>

prometheus:
  buckets: <string>

Attributes

Name	Required	Default	Description	Examples
buckets	false	500,1000,2000,4000,10000	Comma-separated response-time histogram bucket boundaries in milliseconds, applied globally to all proxies. Requests with a response time at or below each boundary are counted in that bucket.	100,500,1000,5000

Can be used in

abort api case chain components for global if interceptor internal otherwise proxy registration request response serviceProxy soapProxy stompProxy time transport wsStompReassembler