[feat] Deduplicate spans based upon their hashcode

cmd/query/app/querysvc/adjusters.go

@@ -14,7 +14,8 @@ import (
 // before returning the data to the API clients.
 func StandardAdjusters(maxClockSkewAdjust time.Duration) []adjuster.Adjuster {
 	return []adjuster.Adjuster{
-		adjuster.SpanIDDeduper(),
+		adjuster.ZipkinSpanIDUniquifier(),
+		adjuster.DedupeBySpanHash(),
 		adjuster.ClockSkew(maxClockSkewAdjust),
 		adjuster.IPTagAdjuster(),
 		adjuster.OTelTagAdjuster(),

model/adjuster/clockskew.go

@@ -19,7 +19,7 @@ import (
 // child spans do not start before or end after their parent spans.
 //
 // The algorithm assumes that all spans have unique IDs, so the trace may need
-// to go through another adjuster first, such as SpanIDDeduper.
+// to go through another adjuster first, such as ZipkinSpanIDUniquifier.
 //
 // This adjuster never returns any errors. Instead it records any issues
 // it encounters in Span.Warnings.

model/adjuster/span_hash_deduper.go

@@ -0,0 +1,46 @@
+// Copyright (c) 2019 The Jaeger Authors.
+// Copyright (c) 2017 Uber Technologies, Inc.
+// SPDX-License-Identifier: Apache-2.0
+
+package adjuster
+
+import (
+	"github.com/jaegertracing/jaeger/model"
+)
+
+// DedupeBySpanHash returns an adjuster that removes all but one span with the same hashcode.
+// This is useful for when spans are duplicated in archival storage, as happens with
+// ElasticSearch archival.
+func DedupeBySpanHash() Adjuster {
+	return Func(func(trace *model.Trace) (*model.Trace, error) {
+		deduper := &spanHashDeduper{trace: trace}
+		deduper.groupSpansByHash()
+		deduper.dedupeSpansByHash()
+		return deduper.trace, nil
+	})
+}
+
+type spanHashDeduper struct {
+	trace       *model.Trace
+	spansByHash map[uint64][]*model.Span
+}
+
+func (d *spanHashDeduper) groupSpansByHash() {
+	spansByHash := make(map[uint64][]*model.Span)
+	for _, span := range d.trace.Spans {
+		hash, _ := model.HashCode(span)
+		if spans, ok := spansByHash[hash]; ok {
+			spansByHash[hash] = append(spans, span)
+		} else {
+			spansByHash[hash] = []*model.Span{span}
+		}
+	}
+	d.spansByHash = spansByHash
+}
+
+func (d *spanHashDeduper) dedupeSpansByHash() {
+	d.trace.Spans = nil
+	for _, spans := range d.spansByHash {
+		d.trace.Spans = append(d.trace.Spans, spans[0])
+	}
+}

model/adjuster/span_hash_deduper_test.go

@@ -0,0 +1,129 @@
+// Copyright (c) 2019 The Jaeger Authors.
+// Copyright (c) 2017 Uber Technologies, Inc.
+// SPDX-License-Identifier: Apache-2.0
+
+package adjuster
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/otel/trace"
+
+	"github.com/jaegertracing/jaeger/model"
+)
+
+func newDuplicatedSpansTrace() *model.Trace {
+	traceID := model.NewTraceID(0, 42)
+	return &model.Trace{
+		Spans: []*model.Span{
+			{
+				TraceID: traceID,
+				SpanID:  clientSpanID,
+				Tags: model.KeyValues{
+					// span.kind = server
+					model.String(keySpanKind, trace.SpanKindServer.String()),
+				},
+			},
+			{
+				TraceID: traceID,
+				SpanID:  clientSpanID, // shared span ID
+				Tags: model.KeyValues{
+					// span.kind = server
+					model.String(keySpanKind, trace.SpanKindServer.String()),
+				},
+			},
+			{
+				// some other span, child of server span
+				TraceID:    traceID,
+				SpanID:     anotherSpanID,
+				References: []model.SpanRef{model.NewChildOfRef(traceID, clientSpanID)},
+			},
+		},
+	}
+}
+
+func newUniqueSpansTrace() *model.Trace {
+	traceID := model.NewTraceID(0, 42)
+	return &model.Trace{
+		Spans: []*model.Span{
+			{
+				TraceID: traceID,
+				SpanID:  anotherSpanID,
+				Tags: model.KeyValues{
+					// span.kind = server
+					model.String(keySpanKind, trace.SpanKindServer.String()),
+				},
+			},
+			{
+				TraceID:    traceID,
+				SpanID:     anotherSpanID, // same ID as before, but different metadata
+				References: []model.SpanRef{model.NewChildOfRef(traceID, clientSpanID)},
+			},
+		},
+	}
+}
+
+func getSpanIDs(spans []*model.Span) []int {
+	ids := make([]int, len(spans))
+	for i, span := range spans {
+		ids[i] = int(span.SpanID)
+	}
+	return ids
+}
+
+func TestDedupeBySpanHashTriggers(t *testing.T) {
+	trace := newDuplicatedSpansTrace()
+	deduper := DedupeBySpanHash()
+	trace, err := deduper.Adjust(trace)
+	require.NoError(t, err)
+
+	assert.Len(t, trace.Spans, 2, "should dedupe spans")
+
+	ids := getSpanIDs(trace.Spans)
+	assert.ElementsMatch(t, []int{int(clientSpanID), int(anotherSpanID)}, ids, "should keep unique span IDs")
+}
+
+func TestDedupeBySpanHashNotTriggered(t *testing.T) {
+	trace := newUniqueSpansTrace()
+	deduper := DedupeBySpanHash()
+	trace, err := deduper.Adjust(trace)
+	require.NoError(t, err)
+
+	assert.Len(t, trace.Spans, 2, "should not dedupe spans")
+
+	ids := getSpanIDs(trace.Spans)
+	assert.ElementsMatch(t, []int{int(anotherSpanID), int(anotherSpanID)}, ids, "should keep unique span IDs")
+	assert.NotEqual(t, trace.Spans[0], trace.Spans[1], "should keep unique hashcodes")
+}
+
+func TestDedupeBySpanHashEmpty(t *testing.T) {
+	trace := &model.Trace{}
+	deduper := DedupeBySpanHash()
+	trace, err := deduper.Adjust(trace)
+	require.NoError(t, err)
+
+	assert.Empty(t, trace.Spans, "should be empty")
+}
+
+func TestDedupeBySpanHashManyManySpans(t *testing.T) {
+	traceID := model.NewTraceID(0, 42)
+	spans := make([]*model.Span, 0, 100)
+	const distinctSpanIDs = 10
+	for i := 0; i < 100; i++ {
+		spans = append(spans, &model.Span{
+			TraceID: traceID,
+			SpanID:  model.SpanID(i % distinctSpanIDs),
+		})
+	}
+	trace := &model.Trace{Spans: spans}
+	deduper := DedupeBySpanHash()
+	trace, err := deduper.Adjust(trace)
+	require.NoError(t, err)
+
+	assert.Len(t, trace.Spans, distinctSpanIDs, "should dedupe spans")
+
+	ids := getSpanIDs(trace.Spans)
+	assert.ElementsMatch(t, []int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}, ids, "should keep unique span IDs")
+}

model/adjuster/span_id_deduper.go → model/adjuster/zipkin_span_id_uniquify.go

@@ -11,19 +11,19 @@ import (
 	"github.com/jaegertracing/jaeger/model"
 )
 
-// SpanIDDeduper returns an adjuster that changes span ids for server
+// ZipkinSpanIDUniquifier returns an adjuster that changes span ids for server
 // spans (i.e. spans with tag: span.kind == server) if there is another
 // client span that shares the same span ID. This is needed to deal with
 // Zipkin-style clients that reuse the same span ID for both client and server
 // side of an RPC call. Jaeger UI expects all spans to have unique IDs.
 //
 // This adjuster never returns any errors. Instead it records any issues
 // it encounters in Span.Warnings.
-func SpanIDDeduper() Adjuster {
+func ZipkinSpanIDUniquifier() Adjuster {
 	return Func(func(trace *model.Trace) (*model.Trace, error) {
 		deduper := &spanIDDeduper{trace: trace}
 		deduper.groupSpansByID()
-		deduper.dedupeSpanIDs()
+		deduper.uniquifyServerSpanIDs()
 		return deduper.trace, nil
 	})
 }
@@ -63,7 +63,7 @@ func (d *spanIDDeduper) isSharedWithClientSpan(spanID model.SpanID) bool {
 	return false
 }
 
-func (d *spanIDDeduper) dedupeSpanIDs() {
+func (d *spanIDDeduper) uniquifyServerSpanIDs() {
 	oldToNewSpanIDs := make(map[model.SpanID]model.SpanID)
 	for _, span := range d.trace.Spans {
 		// only replace span IDs for server-side spans that share the ID with something else
@@ -82,7 +82,7 @@ func (d *spanIDDeduper) dedupeSpanIDs() {
 }
 
 // swapParentIDs corrects ParentSpanID of all spans that are children of the server
-// spans whose IDs we deduped.
+// spans whose IDs we made unique.
 func (d *spanIDDeduper) swapParentIDs(oldToNewSpanIDs map[model.SpanID]model.SpanID) {
 	for _, span := range d.trace.Spans {
 		if parentID, ok := oldToNewSpanIDs[span.ParentSpanID()]; ok {

model/adjuster/span_id_deduper_test.go → model/adjuster/zipkin_span_id_uniquify_test.go

@@ -20,7 +20,7 @@ var (
 	keySpanKind   = "span.kind"
 )
 
-func newTrace() *model.Trace {
+func newZipkinTrace() *model.Trace {
 	traceID := model.NewTraceID(0, 42)
 	return &model.Trace{
 		Spans: []*model.Span{
@@ -52,9 +52,9 @@ func newTrace() *model.Trace {
 	}
 }
 
-func TestSpanIDDeduperTriggered(t *testing.T) {
-	trace := newTrace()
-	deduper := SpanIDDeduper()
+func TestZipkinSpanIDUniquifierTriggered(t *testing.T) {
+	trace := newZipkinTrace()
+	deduper := ZipkinSpanIDUniquifier()
 	trace, err := deduper.Adjust(trace)
 	require.NoError(t, err)
 
@@ -70,11 +70,11 @@ func TestSpanIDDeduperTriggered(t *testing.T) {
 	assert.Equal(t, serverSpan.SpanID, thirdSpan.ParentSpanID(), "server span should be 3rd span's parent")
 }
 
-func TestSpanIDDeduperNotTriggered(t *testing.T) {
-	trace := newTrace()
+func TestZipkinSpanIDUniquifierNotTriggered(t *testing.T) {
+	trace := newZipkinTrace()
 	trace.Spans = trace.Spans[1:] // remove client span
 
-	deduper := SpanIDDeduper()
+	deduper := ZipkinSpanIDUniquifier()
 	trace, err := deduper.Adjust(trace)
 	require.NoError(t, err)
 
@@ -87,16 +87,16 @@ func TestSpanIDDeduperNotTriggered(t *testing.T) {
 	assert.Equal(t, serverSpan.SpanID, thirdSpan.ParentSpanID(), "server span should be 3rd span's parent")
 }
 
-func TestSpanIDDeduperError(t *testing.T) {
-	trace := newTrace()
+func TestZipkinSpanIDUniquifierError(t *testing.T) {
+	trace := newZipkinTrace()
 
 	maxID := int64(-1)
 	assert.Equal(t, maxSpanID, model.NewSpanID(uint64(maxID)), "maxSpanID must be 2^64-1")
 
 	deduper := &spanIDDeduper{trace: trace}
 	deduper.groupSpansByID()
 	deduper.maxUsedID = maxSpanID - 1
-	deduper.dedupeSpanIDs()
+	deduper.uniquifyServerSpanIDs()
 	if assert.Len(t, trace.Spans[1].Warnings, 1) {
 		assert.Equal(t, "cannot assign unique span ID, too many spans in the trace", trace.Spans[1].Warnings[0])
 	}

plugin/storage/memory/memory.go

@@ -59,7 +59,7 @@ func newTenant(cfg Configuration) *Tenant {
 		traces:     map[model.TraceID]*model.Trace{},
 		services:   map[string]struct{}{},
 		operations: map[string]map[spanstore.Operation]struct{}{},
-		deduper:    adjuster.SpanIDDeduper(),
+		deduper:    adjuster.ZipkinSpanIDUniquifier(),
 		config:     cfg,
 	}
 }
@@ -90,7 +90,7 @@ func (st *Store) GetDependencies(ctx context.Context, endTs time.Time, lookback
 	deps := map[string]*model.DependencyLink{}
 	startTs := endTs.Add(-1 * lookback)
 	for _, orig := range m.traces {
-		// SpanIDDeduper never returns an err
+		// ZipkinSpanIDUniquifier never returns an err
 		trace, _ := m.deduper.Adjust(orig)
 		if traceIsBetweenStartAndEnd(startTs, endTs, trace) {
 			for _, s := range trace.Spans {