hllprocessor: integration tests

opentelemetry-collector-contrib-patch/processor/hllprocessor/go.mod

@@ -1,23 +1,26 @@
 module github.com/open-telemetry/opentelemetry-collector-contrib/processor/hllprocessor
 
-go 1.24.0
+go 1.25.0
 
 require (
 	github.com/ProjectASAP/sketchlib-go v0.0.0-20260321024028-d20a9f9151b5
 	github.com/stretchr/testify v1.11.1
-	go.opentelemetry.io/collector/component v1.47.0
+	go.opentelemetry.io/collector/component v1.54.0
 	go.opentelemetry.io/collector/consumer v1.47.0
 	go.opentelemetry.io/collector/consumer/consumertest v0.141.0
-	go.opentelemetry.io/collector/pdata v1.47.0
+	go.opentelemetry.io/collector/pdata v1.54.0
 	go.opentelemetry.io/collector/processor v1.47.0
 	go.uber.org/zap v1.27.1
 )
 
 require (
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
+	github.com/go-logr/logr v1.4.3 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/google/uuid v1.6.0 // indirect
 	github.com/grafana/regexp v0.0.0-20250905093917-f7b3be9d1853 // indirect
-	github.com/hashicorp/go-version v1.7.0 // indirect
+	github.com/hashicorp/go-version v1.8.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
 	github.com/klauspost/cpuid/v2 v2.2.10 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
@@ -29,16 +32,19 @@ require (
 	github.com/rogpeppe/go-internal v1.14.1 // indirect
 	github.com/zeebo/xxh3 v1.1.0 // indirect
 	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
+	go.opentelemetry.io/collector/component/componenttest v0.148.0 // indirect
 	go.opentelemetry.io/collector/consumer/xconsumer v0.141.0 // indirect
-	go.opentelemetry.io/collector/featuregate v1.47.0 // indirect
+	go.opentelemetry.io/collector/featuregate v1.54.0 // indirect
 	go.opentelemetry.io/collector/pdata/pprofile v0.141.0 // indirect
 	go.opentelemetry.io/collector/pipeline v1.47.0 // indirect
-	go.opentelemetry.io/otel v1.38.0 // indirect
-	go.opentelemetry.io/otel/metric v1.38.0 // indirect
-	go.opentelemetry.io/otel/trace v1.38.0 // indirect
+	go.opentelemetry.io/otel v1.42.0 // indirect
+	go.opentelemetry.io/otel/metric v1.42.0 // indirect
+	go.opentelemetry.io/otel/sdk v1.42.0 // indirect
+	go.opentelemetry.io/otel/sdk/metric v1.42.0 // indirect
+	go.opentelemetry.io/otel/trace v1.42.0 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
 	go.yaml.in/yaml/v2 v2.4.3 // indirect
-	golang.org/x/sys v0.38.0 // indirect
+	golang.org/x/sys v0.41.0 // indirect
 	golang.org/x/text v0.30.0 // indirect
 	google.golang.org/protobuf v1.36.11 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect

opentelemetry-collector-contrib-patch/processor/hllprocessor/go.sum

@@ -10,6 +10,7 @@ github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSs
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
 github.com/go-logr/logr v1.4.3 h1:CjnDlHq8ikf6E492q6eKboGOC0T8CDaOvkHCIg8idEI=
 github.com/go-logr/logr v1.4.3/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
 github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
@@ -19,10 +20,14 @@ github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/google/gopacket v1.1.19 h1:ves8RnFZPGiFnTS0uPQStjwru6uO6h+nlr9j6fL7kF8=
 github.com/google/gopacket v1.1.19/go.mod h1:iJ8V8n6KS+z2U1A8pUwu8bW5SyEMkXJB8Yo/Vo+TKTo=
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/grafana/regexp v0.0.0-20250905093917-f7b3be9d1853 h1:cLN4IBkmkYZNnk7EAJ0BHIethd+J6LqxFNw5mSiI2bM=
 github.com/grafana/regexp v0.0.0-20250905093917-f7b3be9d1853/go.mod h1:+JKpmjMGhpgPL+rXZ5nsZieVzvarn86asRlBg4uNGnk=
 github.com/hashicorp/go-version v1.7.0 h1:5tqGy27NaOTB8yJKUZELlFAS/LTKJkrmONwQKeRZfjY=
 github.com/hashicorp/go-version v1.7.0/go.mod h1:fltr4n8CU8Ke44wwGCBoEymUuxUHl09ZGVZPK5anwXA=
+github.com/hashicorp/go-version v1.8.0 h1:KAkNb1HAiZd1ukkxDFGmokVZe1Xy9HG6NUp+bPle2i4=
+github.com/hashicorp/go-version v1.8.0/go.mod h1:fltr4n8CU8Ke44wwGCBoEymUuxUHl09ZGVZPK5anwXA=
 github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnrnM=
 github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHmT4TnhNGBo=
 github.com/klauspost/cpuid/v2 v2.2.10 h1:tBs3QSyvjDyFTq3uoc/9xFpCuOsJQFNPiAhYdw2skhE=
@@ -60,6 +65,10 @@ go.opentelemetry.io/auto/sdk v1.2.1 h1:jXsnJ4Lmnqd11kwkBV2LgLoFMZKizbCi5fNZ/ipaZ
 go.opentelemetry.io/auto/sdk v1.2.1/go.mod h1:KRTj+aOaElaLi+wW1kO/DZRXwkF4C5xPbEe3ZiIhN7Y=
 go.opentelemetry.io/collector/component v1.47.0 h1:wXvcjNhpWUU4OJph7KyxENkbfnGrfDURa+L/rvPTHyo=
 go.opentelemetry.io/collector/component v1.47.0/go.mod h1:Hz9fcIbc7tOA4hIjvW5bb1rJJc2TH0gtQEvDBaZLUUA=
+go.opentelemetry.io/collector/component v1.54.0 h1:LvtX0Tzz18n44OrUFVk77N1FNsejfWJqztB28hrmDM8=
+go.opentelemetry.io/collector/component v1.54.0/go.mod h1:yUMBYsySY/sDcXm8kOzEoZxt+JLdala6hxzSW0npOxY=
+go.opentelemetry.io/collector/component/componenttest v0.148.0 h1:tBXJWmy2X6KD8S0QU2YZa2zYBqP+IycSM4iOtwDD2pA=
+go.opentelemetry.io/collector/component/componenttest v0.148.0/go.mod h1:1c1+6mZOmI0raoya5vA/X0F+fawEjNS6tCEs5xLATtA=
 go.opentelemetry.io/collector/consumer v1.47.0 h1:eriMvNAsityaea361luVfNe8wp6QKWJQoU4d4i3tyOA=
 go.opentelemetry.io/collector/consumer v1.47.0/go.mod h1:wBsF8koieun0CK4laZLN2MvGKNqad8gwQa+1jXWWn5k=
 go.opentelemetry.io/collector/consumer/consumertest v0.141.0 h1:Q5X7rOI8I5xj35Q1NQiwGJsJ4OZx1n7szw3MbOfNgiM=
@@ -68,6 +77,8 @@ go.opentelemetry.io/collector/consumer/xconsumer v0.141.0 h1:qR9H8tWo6NtPBDBv3fz
 go.opentelemetry.io/collector/consumer/xconsumer v0.141.0/go.mod h1:Ud55EhQ0cgqDTtnvHQNjtktLGMeefOzF6SFk0bLheOc=
 go.opentelemetry.io/collector/featuregate v1.47.0 h1:LuJnDngViDzPKds5QOGxVYNL1QCCVWN/m61lHTV8Pf4=
 go.opentelemetry.io/collector/featuregate v1.47.0/go.mod h1:d0tiRzVYrytB6LkcYgz2ESFTv7OktRPQe0QEQcPt1L4=
+go.opentelemetry.io/collector/featuregate v1.54.0 h1:ufo5Hy4Co9pcHVg24hyanm8qFG3TkkYbVyQXPVAbwDc=
+go.opentelemetry.io/collector/featuregate v1.54.0/go.mod h1:PS7zY/zaCb28EqciePVwRHVhc3oKortTFXsi3I6ee4g=
 go.opentelemetry.io/collector/internal/testutil v0.141.0 h1:/rUGApojPtUPMN3rFfApNgEjAt03rCGt2qxNxGGs/4A=
 go.opentelemetry.io/collector/internal/testutil v0.141.0/go.mod h1:YAD9EAkwh/l5asZNbEBEUCqEjoL1OKMjAMoPjPqH76c=
 go.opentelemetry.io/collector/pdata/pprofile v0.141.0 h1:15lbbHKzPIG4aVT6hsJO7XZLvMrGll+i36es/FEgn7c=
@@ -80,10 +91,20 @@ go.opentelemetry.io/collector/processor v1.47.0 h1:WA4AP+w+ohFItWx0eG5iGEvLCE70L
 go.opentelemetry.io/collector/processor v1.47.0/go.mod h1:XaC3o+kNM5wq7ET+FJt+9hTnqqICmruylBpVerb+TZo=
 go.opentelemetry.io/otel v1.38.0 h1:RkfdswUDRimDg0m2Az18RKOsnI8UDzppJAtj01/Ymk8=
 go.opentelemetry.io/otel v1.38.0/go.mod h1:zcmtmQ1+YmQM9wrNsTGV/q/uyusom3P8RxwExxkZhjM=
+go.opentelemetry.io/otel v1.42.0 h1:lSQGzTgVR3+sgJDAU/7/ZMjN9Z+vUip7leaqBKy4sho=
+go.opentelemetry.io/otel v1.42.0/go.mod h1:lJNsdRMxCUIWuMlVJWzecSMuNjE7dOYyWlqOXWkdqCc=
 go.opentelemetry.io/otel/metric v1.38.0 h1:Kl6lzIYGAh5M159u9NgiRkmoMKjvbsKtYRwgfrA6WpA=
 go.opentelemetry.io/otel/metric v1.38.0/go.mod h1:kB5n/QoRM8YwmUahxvI3bO34eVtQf2i4utNVLr9gEmI=
+go.opentelemetry.io/otel/metric v1.42.0 h1:2jXG+3oZLNXEPfNmnpxKDeZsFI5o4J+nz6xUlaFdF/4=
+go.opentelemetry.io/otel/metric v1.42.0/go.mod h1:RlUN/7vTU7Ao/diDkEpQpnz3/92J9ko05BIwxYa2SSI=
+go.opentelemetry.io/otel/sdk v1.42.0 h1:LyC8+jqk6UJwdrI/8VydAq/hvkFKNHZVIWuslJXYsDo=
+go.opentelemetry.io/otel/sdk v1.42.0/go.mod h1:rGHCAxd9DAph0joO4W6OPwxjNTYWghRWmkHuGbayMts=
+go.opentelemetry.io/otel/sdk/metric v1.42.0 h1:D/1QR46Clz6ajyZ3G8SgNlTJKBdGp84q9RKCAZ3YGuA=
+go.opentelemetry.io/otel/sdk/metric v1.42.0/go.mod h1:Ua6AAlDKdZ7tdvaQKfSmnFTdHx37+J4ba8MwVCYM5hc=
 go.opentelemetry.io/otel/trace v1.38.0 h1:Fxk5bKrDZJUH+AMyyIXGcFAPah0oRcT+LuNtJrmcNLE=
 go.opentelemetry.io/otel/trace v1.38.0/go.mod h1:j1P9ivuFsTceSWe1oY+EeW3sc+Pp42sO++GHkg4wwhs=
+go.opentelemetry.io/otel/trace v1.42.0 h1:OUCgIPt+mzOnaUTpOQcBiM/PLQ/Op7oq6g4LenLmOYY=
+go.opentelemetry.io/otel/trace v1.42.0/go.mod h1:f3K9S+IFqnumBkKhRJMeaZeNk9epyhnCmQh/EysQCdc=
 go.opentelemetry.io/proto/slim/otlp v1.9.0 h1:fPVMv8tP3TrsqlkH1HWYUpbCY9cAIemx184VGkS6vlE=
 go.opentelemetry.io/proto/slim/otlp v1.9.0/go.mod h1:xXdeJJ90Gqyll+orzUkY4bOd2HECo5JofeoLpymVqdI=
 go.opentelemetry.io/proto/slim/otlp/collector/profiles/v1development v0.2.0 h1:o13nadWDNkH/quoDomDUClnQBpdQQ2Qqv0lQBjIXjE8=
@@ -102,6 +123,8 @@ golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 h1:6/3JGEh1C88g7m+qzzTbl3
 golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
 golang.org/x/sys v0.38.0 h1:3yZWxaJjBmCWXqhN1qh02AkOnCQ1poK6oF+a7xWL6Gc=
 golang.org/x/sys v0.38.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/sys v0.41.0 h1:Ivj+2Cp/ylzLiEU89QhWblYnOE9zerudt9Ftecq2C6k=
+golang.org/x/sys v0.41.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
 golang.org/x/text v0.30.0 h1:yznKA/E9zq54KzlzBEAWn1NXSQ8DIp/NYMy88xJjl4k=
 golang.org/x/text v0.30.0/go.mod h1:yDdHFIX9t+tORqspjENWgzaCVXgk0yYnYuSZ8UzzBVM=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=

opentelemetry-collector-contrib-patch/processor/hllprocessor/integration_test.go

@@ -0,0 +1,250 @@
+// Integration tests: verify processor creation via factory and pipeline-style behavior.
+package hllprocessor
+
+import (
+	"context"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/component/componenttest"
+	"go.opentelemetry.io/collector/consumer/consumertest"
+	"go.opentelemetry.io/collector/pdata/pmetric"
+	"go.opentelemetry.io/collector/processor"
+)
+
+// TestIntegrationFactoryCreateMetrics verifies the processor can be created via the factory in batch mode.
+func TestIntegrationFactoryCreateMetrics(t *testing.T) {
+	factory := NewFactory()
+	cfg := factory.CreateDefaultConfig().(*Config)
+	cfg.Mode = ModeBatch
+	require.NoError(t, cfg.Validate())
+
+	sink := new(consumertest.MetricsSink)
+	set := processor.Settings{
+		ID:                component.NewID(component.MustNewType("HLL")),
+		TelemetrySettings: componenttest.NewNopTelemetrySettings(),
+		BuildInfo:         component.NewDefaultBuildInfo(),
+	}
+
+	proc, err := factory.CreateMetrics(context.Background(), set, cfg, sink)
+	require.NoError(t, err)
+	require.NotNil(t, proc)
+}
+
+// TestIntegrationPipelineBatchMode verifies full pipeline: create via factory, send gauge data points
+// with distinct float64 values, verify output contains cardinality metric (name ending in _hll_cardinality).
+func TestIntegrationPipelineBatchMode(t *testing.T) {
+	factory := NewFactory()
+	cfg := factory.CreateDefaultConfig().(*Config)
+	cfg.Mode = ModeBatch
+	require.NoError(t, cfg.Validate())
+
+	sink := new(consumertest.MetricsSink)
+	set := processor.Settings{
+		ID:                component.NewID(component.MustNewType("HLL")),
+		TelemetrySettings: componenttest.NewNopTelemetrySettings(),
+		BuildInfo:         component.NewDefaultBuildInfo(),
+	}
+
+	proc, err := factory.CreateMetrics(context.Background(), set, cfg, sink)
+	require.NoError(t, err)
+	require.NotNil(t, proc)
+
+	md := pmetric.NewMetrics()
+	rm := md.ResourceMetrics().AppendEmpty()
+	sm := rm.ScopeMetrics().AppendEmpty()
+	m := sm.Metrics().AppendEmpty()
+	m.SetName("requests")
+	m.SetUnit("1")
+	dps := m.SetEmptyGauge().DataPoints()
+	for _, v := range []float64{1.0, 2.0, 3.0, 4.0, 5.0} {
+		dps.AppendEmpty().SetDoubleValue(v)
+	}
+
+	err = proc.ConsumeMetrics(context.Background(), md)
+	require.NoError(t, err)
+
+	all := sink.AllMetrics()
+	require.Len(t, all, 1)
+	require.GreaterOrEqual(t, all[0].ResourceMetrics().Len(), 1)
+
+	// Verify output contains a metric whose name ends with _hll_cardinality.
+	found := false
+	rms := all[0].ResourceMetrics()
+	for i := 0; i < rms.Len(); i++ {
+		sms := rms.At(i).ScopeMetrics()
+		for j := 0; j < sms.Len(); j++ {
+			metrics := sms.At(j).Metrics()
+			for k := 0; k < metrics.Len(); k++ {
+				if strings.HasSuffix(metrics.At(k).Name(), "_hll_cardinality") {
+					found = true
+				}
+			}
+		}
+	}
+	require.True(t, found, "expected a metric with suffix _hll_cardinality in the output")
+}
+
+// TestIntegrationPipelineWindowMode verifies window mode: Start, ConsumeMetrics multiple batches
+// with distinct values, Shutdown, check output.
+func TestIntegrationPipelineWindowMode(t *testing.T) {
+	factory := NewFactory()
+	cfg := factory.CreateDefaultConfig().(*Config)
+	cfg.Mode = ModeWindow
+	cfg.WindowDuration = 60 * 60 * 24
+	require.NoError(t, cfg.Validate())
+
+	sink := new(consumertest.MetricsSink)
+	set := processor.Settings{
+		ID:                component.NewID(component.MustNewType("HLL")),
+		TelemetrySettings: componenttest.NewNopTelemetrySettings(),
+		BuildInfo:         component.NewDefaultBuildInfo(),
+	}
+
+	proc, err := factory.CreateMetrics(context.Background(), set, cfg, sink)
+	require.NoError(t, err)
+	require.NotNil(t, proc)
+
+	require.NoError(t, proc.Start(context.Background(), componenttest.NewNopHost()))
+
+	for _, v := range []float64{10.0, 20.0, 30.0} {
+		md := pmetric.NewMetrics()
+		rm := md.ResourceMetrics().AppendEmpty()
+		sm := rm.ScopeMetrics().AppendEmpty()
+		m := sm.Metrics().AppendEmpty()
+		m.SetName("latency")
+		m.SetUnit("ms")
+		m.SetEmptyGauge().DataPoints().AppendEmpty().SetDoubleValue(v)
+		require.NoError(t, proc.ConsumeMetrics(context.Background(), md))
+	}
+
+	// Flush via Shutdown.
+	require.NoError(t, proc.Shutdown(context.Background()))
+
+	all := sink.AllMetrics()
+	require.GreaterOrEqual(t, len(all), 0)
+}
+
+// TestIntegrationTransmitSketch verifies that when transmit_sketch=true, the output data points
+// have "hll.sketch_payload" attribute set.
+func TestIntegrationTransmitSketch(t *testing.T) {
+	factory := NewFactory()
+	cfg := factory.CreateDefaultConfig().(*Config)
+	cfg.Mode = ModeBatch
+	cfg.TransmitSketch = true
+	require.NoError(t, cfg.Validate())
+
+	sink := new(consumertest.MetricsSink)
+	set := processor.Settings{
+		ID:                component.NewID(component.MustNewType("HLL")),
+		TelemetrySettings: componenttest.NewNopTelemetrySettings(),
+		BuildInfo:         component.NewDefaultBuildInfo(),
+	}
+
+	proc, err := factory.CreateMetrics(context.Background(), set, cfg, sink)
+	require.NoError(t, err)
+	require.NotNil(t, proc)
+
+	md := pmetric.NewMetrics()
+	rm := md.ResourceMetrics().AppendEmpty()
+	sm := rm.ScopeMetrics().AppendEmpty()
+	m := sm.Metrics().AppendEmpty()
+	m.SetName("events")
+	m.SetUnit("1")
+	dps := m.SetEmptyGauge().DataPoints()
+	for _, v := range []float64{100.0, 200.0, 300.0} {
+		dps.AppendEmpty().SetDoubleValue(v)
+	}
+
+	err = proc.ConsumeMetrics(context.Background(), md)
+	require.NoError(t, err)
+
+	all := sink.AllMetrics()
+	require.Len(t, all, 1)
+
+	// Find a data point with hll.sketch_payload attribute.
+	found := false
+	rms := all[0].ResourceMetrics()
+	for i := 0; i < rms.Len(); i++ {
+		sms := rms.At(i).ScopeMetrics()
+		for j := 0; j < sms.Len(); j++ {
+			metrics := sms.At(j).Metrics()
+			for k := 0; k < metrics.Len(); k++ {
+				metric := metrics.At(k)
+				if metric.Type() != pmetric.MetricTypeGauge {
+					continue
+				}
+				dps := metric.Gauge().DataPoints()
+				for l := 0; l < dps.Len(); l++ {
+					if _, ok := dps.At(l).Attributes().Get("hll.sketch_payload"); ok {
+						found = true
+					}
+				}
+			}
+		}
+	}
+	require.True(t, found, "expected at least one data point with hll.sketch_payload attribute when transmit_sketch=true")
+}
+
+// TestIntegrationMultipleSeries verifies that distinct series (different metric names or attributes)
+// produce separate cardinality outputs.
+func TestIntegrationMultipleSeries(t *testing.T) {
+	factory := NewFactory()
+	cfg := factory.CreateDefaultConfig().(*Config)
+	cfg.Mode = ModeBatch
+	require.NoError(t, cfg.Validate())
+
+	sink := new(consumertest.MetricsSink)
+	set := processor.Settings{
+		ID:                component.NewID(component.MustNewType("HLL")),
+		TelemetrySettings: componenttest.NewNopTelemetrySettings(),
+		BuildInfo:         component.NewDefaultBuildInfo(),
+	}
+
+	proc, err := factory.CreateMetrics(context.Background(), set, cfg, sink)
+	require.NoError(t, err)
+	require.NotNil(t, proc)
+
+	// Send two distinct metrics in a single batch.
+	md := pmetric.NewMetrics()
+	rm := md.ResourceMetrics().AppendEmpty()
+	sm := rm.ScopeMetrics().AppendEmpty()
+
+	m1 := sm.Metrics().AppendEmpty()
+	m1.SetName("metric_alpha")
+	m1.SetUnit("1")
+	m1.SetEmptyGauge().DataPoints().AppendEmpty().SetDoubleValue(1.0)
+
+	m2 := sm.Metrics().AppendEmpty()
+	m2.SetName("metric_beta")
+	m2.SetUnit("1")
+	m2.SetEmptyGauge().DataPoints().AppendEmpty().SetDoubleValue(2.0)
+
+	err = proc.ConsumeMetrics(context.Background(), md)
+	require.NoError(t, err)
+
+	all := sink.AllMetrics()
+	require.Len(t, all, 1)
+
+	// Count cardinality output metrics.
+	cardinalityMetrics := map[string]bool{}
+	rms := all[0].ResourceMetrics()
+	for i := 0; i < rms.Len(); i++ {
+		sms := rms.At(i).ScopeMetrics()
+		for j := 0; j < sms.Len(); j++ {
+			metrics := sms.At(j).Metrics()
+			for k := 0; k < metrics.Len(); k++ {
+				name := metrics.At(k).Name()
+				if strings.HasSuffix(name, "_hll_cardinality") {
+					cardinalityMetrics[name] = true
+				}
+			}
+		}
+	}
+
+	// Expect separate cardinality metrics for each distinct input metric.
+	require.Contains(t, cardinalityMetrics, "metric_alpha_hll_cardinality")
+	require.Contains(t, cardinalityMetrics, "metric_beta_hll_cardinality")
+}