fix: Sampling Processor not removing higher level objs (#1879)

* test fix for logs

* add log msg

* remove resource logs too

* remove scope and resource level objs for traces & metrics

* add test for verifying behavior

go.mod

@@ -78,8 +78,8 @@ require (
 	github.com/open-telemetry/opentelemetry-collector-contrib/extension/pprofextension v0.109.0
 	github.com/open-telemetry/opentelemetry-collector-contrib/extension/sigv4authextension v0.109.0
 	github.com/open-telemetry/opentelemetry-collector-contrib/extension/storage/filestorage v0.109.0
-	github.com/open-telemetry/opentelemetry-collector-contrib/pkg/golden v0.109.0
-	github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatatest v0.109.0
+	github.com/open-telemetry/opentelemetry-collector-contrib/pkg/golden v0.110.0
+	github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatatest v0.110.0
 	github.com/open-telemetry/opentelemetry-collector-contrib/processor/attributesprocessor v0.109.0
 	github.com/open-telemetry/opentelemetry-collector-contrib/processor/cumulativetodeltaprocessor v0.109.0
 	github.com/open-telemetry/opentelemetry-collector-contrib/processor/deltatorateprocessor v0.109.0
@@ -184,7 +184,7 @@ require (
 	go.opentelemetry.io/collector/extension/zpagesextension v0.109.0
 	go.opentelemetry.io/collector/featuregate v1.15.0
 	go.opentelemetry.io/collector/otelcol v0.109.0
-	go.opentelemetry.io/collector/pdata v1.15.0
+	go.opentelemetry.io/collector/pdata v1.16.0
 	go.opentelemetry.io/collector/processor v0.109.0
 	go.opentelemetry.io/collector/processor/batchprocessor v0.109.0
 	go.opentelemetry.io/collector/processor/memorylimiterprocessor v0.109.0
@@ -438,7 +438,7 @@ require (
 	github.com/Azure/azure-amqp-common-go/v4 v4.2.0 // indirect
 	github.com/bmatcuk/doublestar/v4 v4.6.1 // indirect
 	github.com/hooklift/gowsdl v0.5.0 // indirect
-	github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatautil v0.109.0 // indirect; indir2ct
+	github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatautil v0.110.0 // indirect; indir2ct
 	github.com/ovh/go-ovh v1.6.0 // indirect
 	github.com/relvacode/iso8601 v1.4.0 // indirect
 )

go.sum

@@ -2052,14 +2052,14 @@ github.com/open-telemetry/opentelemetry-collector-contrib/pkg/batchpersignal v0.
 github.com/open-telemetry/opentelemetry-collector-contrib/pkg/batchpersignal v0.109.0/go.mod h1:1aJ+q3jFR+UVsitJF03xKrJ/+N8QyHIs9yWoRS85498=
 github.com/open-telemetry/opentelemetry-collector-contrib/pkg/experimentalmetricmetadata v0.109.0 h1:T6rvvaY1PW5Oqwb3fhFy89UARRoveqtSLh6t5uvktes=
 github.com/open-telemetry/opentelemetry-collector-contrib/pkg/experimentalmetricmetadata v0.109.0/go.mod h1:EWEI4jcMr9jXlBWTG77rqknzc3K+QObImve7y5vdnjs=
-github.com/open-telemetry/opentelemetry-collector-contrib/pkg/golden v0.109.0 h1:9mStsYv/9nnav/mftmHxEA6fp7c7mfd5CgU2802frjE=
-github.com/open-telemetry/opentelemetry-collector-contrib/pkg/golden v0.109.0/go.mod h1:P7e6ch+uoSfxK+lMwfcndkHE6gWUqvWKpr7mD04KIAA=
+github.com/open-telemetry/opentelemetry-collector-contrib/pkg/golden v0.110.0 h1:07mGeb5o9W6DcT1xlXBX5pHamVO9bcro0pFct/z0Ivs=
+github.com/open-telemetry/opentelemetry-collector-contrib/pkg/golden v0.110.0/go.mod h1:eazQnU3D7Xwyctq8Yfig4ws5HcnD3G+ygWrG9H03JjE=
 github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl v0.109.0 h1:k7uHhrznH4dYvzbaCRz5VgFyHzhd1NGow1s6504r6tA=
 github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl v0.109.0/go.mod h1:LfwqmbImTBZW5psp7tCyZPHIPy3Imwexq+K/A1NAhEY=
-github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatatest v0.109.0 h1:Mi0qKcH4VjyyZsbaWYG038drk5FCFL7igVM8abEL4ZY=
-github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatatest v0.109.0/go.mod h1:KvJWxR0bDk9Qh0ktw4gOFsd/ZrJ7p5KTAQueEJsaK9Q=
-github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatautil v0.109.0 h1:3kXFgdEEKw37ftdRC7SmXAiZuLahVavqOYRhlJVMLc8=
-github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatautil v0.109.0/go.mod h1:HtaWI5WJKJkBhHz2R7Xb2n7R3fdBPhfKieYcQajNCTo=
+github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatatest v0.110.0 h1:/kMxDplBmo99UQwkpnCkHO3mwBD6/YcX/ldwlZSURFw=
+github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatatest v0.110.0/go.mod h1:nn/ktwLdZ6O9mtnRuak8NQEfGRow3VI3l+YqAroJX7g=
+github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatautil v0.110.0 h1:KYBzbgQyCz4i5zjzs0iBOFuNh2vagaw2seqvZ7Lftxk=
+github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatautil v0.110.0/go.mod h1:zLtbGLswPAKzTHM4C1Pcxb+PgNHgo6aGVZQtQaeBtec=
 github.com/open-telemetry/opentelemetry-collector-contrib/pkg/resourcetotelemetry v0.109.0 h1:q3rHsRNnB97Xw2rjTBW1qpw6y+LP2xWSRbmTJtPIyQM=
 github.com/open-telemetry/opentelemetry-collector-contrib/pkg/resourcetotelemetry v0.109.0/go.mod h1:vo39/3CexkMcF+T0T8Ic/Oer/ErrSMiD+MWNBYo9VYE=
 github.com/open-telemetry/opentelemetry-collector-contrib/pkg/sampling v0.109.0 h1:YQB8+grNfmaLqiavbv4VKhBw1NF8O6pSmbLC+FjMrKM=
@@ -2681,8 +2681,8 @@ go.opentelemetry.io/collector/otelcol v0.109.0 h1:x7hcrV3lnCg7Ub0Q5haLRFWmqS3mPi
 go.opentelemetry.io/collector/otelcol v0.109.0/go.mod h1:LR2qca0GFWd2yZFBaSTpTIPqnAXJM3gmes++nZNx4ms=
 go.opentelemetry.io/collector/otelcol/otelcoltest v0.109.0 h1:j1jEq+iBfzc2XrFZphQOz2VoYlsOLqZFnBTWZfTq+yU=
 go.opentelemetry.io/collector/otelcol/otelcoltest v0.109.0/go.mod h1:Fcacbap4v39ymbW6AlgZQUqcQm+YMo2rO9izv66IpwQ=
-go.opentelemetry.io/collector/pdata v1.15.0 h1:q/T1sFpRKJnjDrUsHdJ6mq4uSqViR/f92yvGwDby/gY=
-go.opentelemetry.io/collector/pdata v1.15.0/go.mod h1:2wcsTIiLAJSbqBq/XUUYbi+cP+N87d0jEJzmb9nT19U=
+go.opentelemetry.io/collector/pdata v1.16.0 h1:g02K8jlRnmQ7TQDuXpdgVL6vIxIVqr5Gbb1qIR27rto=
+go.opentelemetry.io/collector/pdata v1.16.0/go.mod h1:YZZJIt2ehxosYf/Y1pbvexjNWsIGNNrzzlCTO9jC1F4=
 go.opentelemetry.io/collector/pdata/pprofile v0.109.0 h1:5lobQKeHk8p4WC7KYbzL6ZqqX3eSizsdmp5vM8pQFBs=
 go.opentelemetry.io/collector/pdata/pprofile v0.109.0/go.mod h1:lXIifCdtR5ewO17JAYTUsclMqRp6h6dCowoXHhGyw8Y=
 go.opentelemetry.io/collector/pdata/testdata v0.109.0 h1:gvIqy6juvqFET/6zi+zUOH1KZY/vtEDZW55u7gJ/hEo=

processor/samplingprocessor/go.mod

@@ -8,11 +8,16 @@ require (
 	github.com/stretchr/testify v1.9.0
 	go.opentelemetry.io/collector/component v0.109.0
 	go.opentelemetry.io/collector/consumer v0.109.0
-	go.opentelemetry.io/collector/pdata v1.15.0
+	go.opentelemetry.io/collector/pdata v1.16.0
 	go.opentelemetry.io/collector/processor v0.109.0
 	go.uber.org/zap v1.27.0
 )
 
+require (
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatautil v0.110.0 // indirect
+)
+
 require (
 	github.com/alecthomas/participle/v2 v2.1.1 // indirect
 	github.com/antonmedv/expr v1.15.5 // indirect
@@ -29,6 +34,7 @@ require (
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/open-telemetry/opentelemetry-collector-contrib/internal/coreinternal v0.109.0 // indirect
+	github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatatest v0.110.0
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/ua-parser/uap-go v0.0.0-20240611065828-3a4781585db6 // indirect
 	go.opentelemetry.io/collector v0.109.0 // indirect
@@ -45,7 +51,7 @@ require (
 	golang.org/x/sys v0.24.0 // indirect
 	golang.org/x/text v0.17.0 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20240822170219-fc7c04adadcd // indirect
-	google.golang.org/grpc v1.66.0 // indirect
+	google.golang.org/grpc v1.66.2 // indirect
 	google.golang.org/protobuf v1.34.2 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect

processor/samplingprocessor/go.sum

@@ -57,8 +57,14 @@ github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq
 github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
 github.com/open-telemetry/opentelemetry-collector-contrib/internal/coreinternal v0.109.0 h1:4VBRgtyh3hHSgAVGgs4bvNwJd0oUGyxVA3eQO2ujNsA=
 github.com/open-telemetry/opentelemetry-collector-contrib/internal/coreinternal v0.109.0/go.mod h1:9MGQCqxdCNBhdD+7QBZ6hH9HipXe5CajMafVKglD5f0=
+github.com/open-telemetry/opentelemetry-collector-contrib/pkg/golden v0.110.0 h1:07mGeb5o9W6DcT1xlXBX5pHamVO9bcro0pFct/z0Ivs=
+github.com/open-telemetry/opentelemetry-collector-contrib/pkg/golden v0.110.0/go.mod h1:eazQnU3D7Xwyctq8Yfig4ws5HcnD3G+ygWrG9H03JjE=
 github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl v0.109.0 h1:k7uHhrznH4dYvzbaCRz5VgFyHzhd1NGow1s6504r6tA=
 github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl v0.109.0/go.mod h1:LfwqmbImTBZW5psp7tCyZPHIPy3Imwexq+K/A1NAhEY=
+github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatatest v0.110.0 h1:/kMxDplBmo99UQwkpnCkHO3mwBD6/YcX/ldwlZSURFw=
+github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatatest v0.110.0/go.mod h1:nn/ktwLdZ6O9mtnRuak8NQEfGRow3VI3l+YqAroJX7g=
+github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatautil v0.110.0 h1:KYBzbgQyCz4i5zjzs0iBOFuNh2vagaw2seqvZ7Lftxk=
+github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatautil v0.110.0/go.mod h1:zLtbGLswPAKzTHM4C1Pcxb+PgNHgo6aGVZQtQaeBtec=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_golang v1.20.2 h1:5ctymQzZlyOON1666svgwn3s6IKWgfbjsejTMiXIyjg=
@@ -93,8 +99,8 @@ go.opentelemetry.io/collector/consumer/consumerprofiles v0.109.0 h1:+WZ6MEWQRC6s
 go.opentelemetry.io/collector/consumer/consumerprofiles v0.109.0/go.mod h1:spZ9Dn1MRMPDHHThdXZA5TrFhdOL1wsl0Dw45EBVoVo=
 go.opentelemetry.io/collector/consumer/consumertest v0.109.0 h1:v4w9G2MXGJ/eabCmX1DvQYmxzdysC8UqIxa/BWz7ACo=
 go.opentelemetry.io/collector/consumer/consumertest v0.109.0/go.mod h1:lECt0qOrx118wLJbGijtqNz855XfvJv0xx9GSoJ8qSE=
-go.opentelemetry.io/collector/pdata v1.15.0 h1:q/T1sFpRKJnjDrUsHdJ6mq4uSqViR/f92yvGwDby/gY=
-go.opentelemetry.io/collector/pdata v1.15.0/go.mod h1:2wcsTIiLAJSbqBq/XUUYbi+cP+N87d0jEJzmb9nT19U=
+go.opentelemetry.io/collector/pdata v1.16.0 h1:g02K8jlRnmQ7TQDuXpdgVL6vIxIVqr5Gbb1qIR27rto=
+go.opentelemetry.io/collector/pdata v1.16.0/go.mod h1:YZZJIt2ehxosYf/Y1pbvexjNWsIGNNrzzlCTO9jC1F4=
 go.opentelemetry.io/collector/pdata/pprofile v0.109.0 h1:5lobQKeHk8p4WC7KYbzL6ZqqX3eSizsdmp5vM8pQFBs=
 go.opentelemetry.io/collector/pdata/pprofile v0.109.0/go.mod h1:lXIifCdtR5ewO17JAYTUsclMqRp6h6dCowoXHhGyw8Y=
 go.opentelemetry.io/collector/pdata/testdata v0.109.0 h1:gvIqy6juvqFET/6zi+zUOH1KZY/vtEDZW55u7gJ/hEo=
@@ -158,8 +164,8 @@ golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8T
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20240822170219-fc7c04adadcd h1:6TEm2ZxXoQmFWFlt1vNxvVOa1Q0dXFQD1m/rYjXmS0E=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20240822170219-fc7c04adadcd/go.mod h1:UqMtugtsSgubUsoxbuAoiCXvqvErP7Gf0so0mK9tHxU=
-google.golang.org/grpc v1.66.0 h1:DibZuoBznOxbDQxRINckZcUvnCEvrW9pcWIE2yF9r1c=
-google.golang.org/grpc v1.66.0/go.mod h1:s3/l6xSSCURdVfAnL+TqCNMyTDAGN6+lZeVxnZR128Y=
+google.golang.org/grpc v1.66.2 h1:3QdXkuq3Bkh7w+ywLdLvM56cmGvQHUMZpiCzt6Rqaoo=
+google.golang.org/grpc v1.66.2/go.mod h1:s3/l6xSSCURdVfAnL+TqCNMyTDAGN6+lZeVxnZR128Y=
 google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6hg=
 google.golang.org/protobuf v1.34.2/go.mod h1:qYOHts0dSfpeUzUFpOMr/WGzszTmLH+DiWniOlNbLDw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

processor/samplingprocessor/processor.go

@@ -111,7 +111,13 @@ func (sp *tracesSamplingProcessor) processTraces(ctx context.Context, td ptrace.
 				return err == nil && match && sampleFunc(sp.dropCutOffRatio)
 			})
 		}
+		td.ResourceSpans().At(i).ScopeSpans().RemoveIf(func(ss ptrace.ScopeSpans) bool {
+			return ss.Spans().Len() == 0
+		})
 	}
+	td.ResourceSpans().RemoveIf(func(rs ptrace.ResourceSpans) bool {
+		return rs.ScopeSpans().Len() == 0
+	})
 	return td, nil
 }
 
@@ -145,7 +151,13 @@ func (sp *logsSamplingProcessor) processLogs(ctx context.Context, ld plog.Logs)
 				return err == nil && match && sampleFunc(sp.dropCutOffRatio)
 			})
 		}
+		ld.ResourceLogs().At(i).ScopeLogs().RemoveIf(func(sl plog.ScopeLogs) bool {
+			return sl.LogRecords().Len() == 0
+		})
 	}
+	ld.ResourceLogs().RemoveIf(func(rl plog.ResourceLogs) bool {
+		return rl.ScopeLogs().Len() == 0
+	})
 	return ld, nil
 }
 
@@ -180,6 +192,12 @@ func (sp *metricsSamplingProcessor) processMetrics(ctx context.Context, md pmetr
 				return err == nil && match && sampleFunc(sp.dropCutOffRatio)
 			})
 		}
+		md.ResourceMetrics().At(i).ScopeMetrics().RemoveIf(func(sm pmetric.ScopeMetrics) bool {
+			return sm.Metrics().Len() == 0
+		})
 	}
+	md.ResourceMetrics().RemoveIf(func(rm pmetric.ResourceMetrics) bool {
+		return rm.ScopeMetrics().Len() == 0
+	})
 	return md, nil
 }

processor/samplingprocessor/processor_test.go

@@ -16,9 +16,13 @@ package samplingprocessor
 
 import (
 	"context"
+	"fmt"
 	"testing"
 
 	"github.com/observiq/bindplane-agent/expr"
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatatest/plogtest"
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatatest/pmetrictest"
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatatest/ptracetest"
 	"github.com/stretchr/testify/require"
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/pdata/plog"
@@ -259,3 +263,112 @@ func Test_processMetrics(t *testing.T) {
 		})
 	}
 }
+
+func Test_completeResourceDropping(t *testing.T) {
+	cfg := &Config{
+		DropRatio: 0.5,
+		Condition: "true",
+	}
+
+	t.Run("verify no empty logs", func(t *testing.T) {
+		ld := plog.NewLogs()
+		for i := 0; i < 2; i++ {
+			rl := ld.ResourceLogs().AppendEmpty()
+			for j := 0; j < 3; j++ {
+				sl := rl.ScopeLogs().AppendEmpty()
+
+				lr := sl.LogRecords().AppendEmpty()
+				lr.Body().SetEmptyMap()
+				lr.Body().Map().PutStr("id", fmt.Sprintf("rl-%d/sl-%d/lr", i, j))
+			}
+		}
+
+		ottlCondition, err := expr.NewOTTLLogRecordCondition(cfg.Condition, component.TelemetrySettings{Logger: zap.NewNop()})
+		require.NoError(t, err)
+		processor := newLogsSamplingProcessor(zap.NewNop(), cfg, ottlCondition)
+
+		actual, err := processor.processLogs(context.Background(), ld)
+		require.NoError(t, err)
+
+		// can't know for sure how many logs are removed, but at 50% we can safely assume not all logs are removed
+		err = plogtest.CompareLogs(plog.NewLogs(), actual)
+		require.Error(t, err)
+
+		for i := 0; i < actual.ResourceLogs().Len(); i++ {
+			rl := actual.ResourceLogs().At(i)
+			require.NotEqual(t, 0, rl.ScopeLogs().Len())
+			for j := 0; j < rl.ScopeLogs().Len(); j++ {
+				sl := rl.ScopeLogs().At(j)
+				require.NotEqual(t, 0, sl.LogRecords().Len())
+			}
+		}
+	})
+
+	t.Run("verify no empty traces", func(t *testing.T) {
+		td := ptrace.NewTraces()
+		for i := 0; i < 2; i++ {
+			rt := td.ResourceSpans().AppendEmpty()
+			for j := 0; j < 3; j++ {
+				st := rt.ScopeSpans().AppendEmpty()
+
+				sd := st.Spans().AppendEmpty()
+				m := sd.Attributes().PutEmptyMap("test")
+				m.PutStr("id", fmt.Sprintf("rt-%d/st-%d/s", i, j))
+			}
+		}
+
+		ottlCondition, err := expr.NewOTTLSpanCondition(cfg.Condition, component.TelemetrySettings{Logger: zap.NewNop()})
+		require.NoError(t, err)
+		processor := newTracesSamplingProcessor(zap.NewNop(), cfg, ottlCondition)
+
+		actual, err := processor.processTraces(context.Background(), td)
+		require.NoError(t, err)
+
+		// can't know for sure how many traces are removed, but at 50% we can safely assume not all traces are removed
+		err = ptracetest.CompareTraces(ptrace.NewTraces(), actual)
+		require.Error(t, err)
+
+		for i := 0; i < actual.ResourceSpans().Len(); i++ {
+			rt := actual.ResourceSpans().At(i)
+			require.NotEqual(t, 0, rt.ScopeSpans().Len())
+			for j := 0; j < rt.ScopeSpans().Len(); j++ {
+				st := rt.ScopeSpans().At(j)
+				require.NotEqual(t, 0, st.Spans().Len())
+			}
+		}
+	})
+
+	t.Run("verify no empty metrics", func(t *testing.T) {
+		md := pmetric.NewMetrics()
+		for i := 0; i < 2; i++ {
+			rm := md.ResourceMetrics().AppendEmpty()
+			for j := 0; j < 3; j++ {
+				sm := rm.ScopeMetrics().AppendEmpty()
+
+				m := sm.Metrics().AppendEmpty()
+				m.SetName(fmt.Sprintf("rm-%d/sm-%d/m", i, j))
+			}
+		}
+
+		ottlCondition, err := expr.NewOTTLMetricCondition(cfg.Condition, component.TelemetrySettings{Logger: zap.NewNop()})
+		require.NoError(t, err)
+		processor := newMetricsSamplingProcessor(zap.NewNop(), cfg, ottlCondition)
+
+		actual, err := processor.processMetrics(context.Background(), md)
+		require.NoError(t, err)
+
+		// can't know for sure how many traces are removed, but at 50% we can safely assume not all traces are removed
+		err = pmetrictest.CompareMetrics(pmetric.NewMetrics(), actual)
+		require.Error(t, err)
+
+		for i := 0; i < actual.ResourceMetrics().Len(); i++ {
+			rm := actual.ResourceMetrics().At(i)
+			require.NotEqual(t, 0, rm.ScopeMetrics().Len())
+			for j := 0; j < rm.ScopeMetrics().Len(); j++ {
+				sm := rm.ScopeMetrics().At(j)
+				require.NotEqual(t, 0, sm.Metrics().Len())
+			}
+		}
+
+	})
+}