From a1fc6a6f9da3b1ad36c17e2b1cea69e9f50a4f56 Mon Sep 17 00:00:00 2001
From: Gustaf Lindstedt <gustaf.lindstedt@embark-studios.com>
Date: Wed, 9 Aug 2023 15:22:25 +0200
Subject: [PATCH] Work around high cardinality metrics from otelcol receivers

Fixes #4764
---
 component/otelcol/internal/views/views.go | 53 +++++++++++++++++++++++
 component/otelcol/receiver/receiver.go    |  6 ++-
 2 files changed, 58 insertions(+), 1 deletion(-)
 create mode 100644 component/otelcol/internal/views/views.go

diff --git a/component/otelcol/internal/views/views.go b/component/otelcol/internal/views/views.go
new file mode 100644
index 000000000000..b78e0098f9d6
--- /dev/null
+++ b/component/otelcol/internal/views/views.go
@@ -0,0 +1,53 @@
+package views
+
+import (
+	semconv "go.opentelemetry.io/collector/semconv/v1.13.0"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/sdk/instrumentation"
+	"go.opentelemetry.io/otel/sdk/metric"
+)
+
+var (
+	grpcScope = "go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
+	// grpcUnacceptableKeyValues is a list of high cardinality grpc attributes that should be filtered out.
+	grpcUnacceptableKeyValues = []attribute.KeyValue{
+		attribute.String(semconv.AttributeNetSockPeerAddr, ""),
+		attribute.String(semconv.AttributeNetSockPeerPort, ""),
+		attribute.String(semconv.AttributeNetSockPeerName, ""),
+	}
+
+	httpScope = "go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
+	// httpUnacceptableKeyValues is a list of high cardinality http attributes that should be filtered out.
+	httpUnacceptableKeyValues = []attribute.KeyValue{
+		attribute.String(semconv.AttributeNetHostName, ""),
+		attribute.String(semconv.AttributeNetHostPort, ""),
+		attribute.String(semconv.AttributeNetSockPeerPort, ""),
+		attribute.String(semconv.AttributeNetSockPeerAddr, ""),
+		attribute.String(semconv.AttributeHTTPClientIP, ""),
+	}
+)
+
+func cardinalityFilter(kvs ...attribute.KeyValue) attribute.Filter {
+	filter := attribute.NewSet(kvs...)
+	return func(kv attribute.KeyValue) bool {
+		return !filter.HasValue(kv.Key)
+	}
+}
+
+// DropHighCardinalityServerAttributes drops certain high cardinality attributes from grpc/http server metrics
+//
+// This is a hopefully temporary fix to this upstream issue https://github.com/open-telemetry/opentelemetry-go-contrib/issues/3765
+func DropHighCardinalityServerAttributes() []metric.View {
+	var views []metric.View
+
+	views = append(views, metric.NewView(
+		metric.Instrument{Scope: instrumentation.Scope{Name: grpcScope}},
+		metric.Stream{AttributeFilter: cardinalityFilter(grpcUnacceptableKeyValues...)}))
+
+	views = append(views, metric.NewView(
+		metric.Instrument{Scope: instrumentation.Scope{Name: httpScope}},
+		metric.Stream{AttributeFilter: cardinalityFilter(httpUnacceptableKeyValues...)},
+	))
+
+	return views
+}
diff --git a/component/otelcol/receiver/receiver.go b/component/otelcol/receiver/receiver.go
index 64b111bfc46d..3d4c55198ca9 100644
--- a/component/otelcol/receiver/receiver.go
+++ b/component/otelcol/receiver/receiver.go
@@ -12,6 +12,7 @@ import (
 	"github.com/grafana/agent/component/otelcol/internal/fanoutconsumer"
 	"github.com/grafana/agent/component/otelcol/internal/lazycollector"
 	"github.com/grafana/agent/component/otelcol/internal/scheduler"
+	"github.com/grafana/agent/component/otelcol/internal/views"
 	"github.com/grafana/agent/pkg/build"
 	"github.com/grafana/agent/pkg/util/zapadapter"
 	"github.com/prometheus/client_golang/prometheus"
@@ -125,7 +126,10 @@ func (r *Receiver) Update(args component.Arguments) error {
 			Logger: zapadapter.New(r.opts.Logger),
 
 			TracerProvider: r.opts.Tracer,
-			MeterProvider:  metric.NewMeterProvider(metric.WithReader(promExporter)),
+			MeterProvider: metric.NewMeterProvider(
+				metric.WithReader(promExporter),
+				metric.WithView(views.DropHighCardinalityServerAttributes()...),
+			),
 		},
 
 		BuildInfo: otelcomponent.BuildInfo{