ignore requests with header in metrics

pkg/queue/request_metric.go

@@ -109,8 +109,8 @@ func (h *requestMetricsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request
 	startTime := time.Now()
 
 	defer func() {
-		// Filter probe requests for revision metrics.
-		if netheader.IsProbe(r) {
+		// Filter probe requests and requests marked by ignore metrics header for revision metrics.
+		if netheader.IsProbe(r) || netheader.IsMetricsIgnored(r) {
 			return
 		}
 
@@ -177,8 +177,8 @@ func (h *appRequestMetricsHandler) ServeHTTP(w http.ResponseWriter, r *http.Requ
 		pkgmetrics.Record(h.statsCtx, queueDepthM.M(int64(h.breaker.InFlight())))
 	}
 	defer func() {
-		// Filter probe requests for revision metrics.
-		if netheader.IsProbe(r) {
+		// Filter probe requests and requests marked by ignore metrics header for revision metrics.
+		if netheader.IsProbe(r) || netheader.IsMetricsIgnored(r) {
 			return
 		}
 

vendor/knative.dev/networking/pkg/http/header/header.go

@@ -78,6 +78,9 @@ const (
 	// load balancers to not load balance the respective request but to
 	// send it to the request's target directly.
 	PassthroughLoadbalancingKey = "K-Passthrough-Lb"
+
+	// IgnoreMetricsKey is used to mark requests that should not be counted in metrics.
+	IgnoreMetricsKey = "K-Ignore-Metrics"
 )
 
 // User Agent Key & Values
@@ -135,6 +138,11 @@ func IsKubeletProbe(r *http.Request) bool {
 		r.Header.Get(KubeletProbeKey) != ""
 }
 
+// IsMetricsIgnored returns true if the request is marked to be ignored by metrics.
+func IsMetricsIgnored(r *http.Request) bool {
+  return r.Header.Get(IgnoreMetricsKey) != ""
+}
+
 // RewriteHostIn removes the `Host` header from the inbound (server) request
 // and replaces it with our custom header.
 // This is done to avoid Istio Host based routing, see #3870.