minimal trace init for custom service name

Signed-off-by: sallyom <[email protected]>

Author: sallyom

pkg/kvcache/indexer.go

@@ -20,14 +20,14 @@ import (
 	"context"
 	"fmt"
 
-	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/attribute"
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/klog/v2"
 
 	"github.com/llm-d/llm-d-kv-cache-manager/pkg/kvcache/kvblock"
 	"github.com/llm-d/llm-d-kv-cache-manager/pkg/tokenization"
 	"github.com/llm-d/llm-d-kv-cache-manager/pkg/tokenization/prefixstore"
+	"github.com/llm-d/llm-d-kv-cache-manager/pkg/tracing"
 	"github.com/llm-d/llm-d-kv-cache-manager/pkg/utils/logging"
 )
 
@@ -119,7 +119,7 @@ func (k *Indexer) KVBlockIndex() kvblock.Index {
 func (k *Indexer) GetPodScores(ctx context.Context, prompt, modelName string,
 	podIdentifiers []string,
 ) (map[string]int, error) {
-	tracer := otel.GetTracerProvider().Tracer("llm-d-kv-cache")
+	tracer := tracing.GetTracer()
 	ctx, span := tracer.Start(ctx, "kv-cache-manager.GetPodScores")
 	defer span.End()
 

pkg/tracing/tracing.go

@@ -0,0 +1,81 @@
+/*
+Copyright 2025 The llm-d Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package tracing
+
+import (
+	"context"
+	"os"
+	"sync"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp"
+	"go.opentelemetry.io/otel/sdk/resource"
+	"go.opentelemetry.io/otel/sdk/trace"
+	semconv "go.opentelemetry.io/otel/semconv/v1.21.0"
+	oteltrace "go.opentelemetry.io/otel/trace"
+)
+
+var (
+	customProvider oteltrace.TracerProvider
+	once           sync.Once
+)
+
+// GetTracer returns a tracer for the KV cache component
+func GetTracer() oteltrace.Tracer {
+	// If auto-instrumentation is detected, create custom provider with different service name
+	if os.Getenv("OTEL_SERVICE_NAME") != "" {
+		return getCustomTracerProvider().Tracer("llm-d-kv-cache-manager")
+	}
+	// Fallback to global provider
+	return otel.GetTracerProvider().Tracer("llm-d-kv-cache")
+}
+
+func getCustomTracerProvider() oteltrace.TracerProvider {
+	once.Do(func() {
+		customProvider = createCustomTracerProvider()
+	})
+	return customProvider
+}
+
+func createCustomTracerProvider() oteltrace.TracerProvider {
+	ctx := context.Background()
+	// Use same endpoint as auto-instrumentation
+	endpoint := os.Getenv("OTEL_EXPORTER_OTLP_ENDPOINT")
+	if endpoint == "" {
+		return otel.GetTracerProvider()
+	}
+	exporter, err := otlptracehttp.New(ctx,
+		otlptracehttp.WithEndpoint(endpoint),
+		otlptracehttp.WithInsecure(),
+	)
+	if err != nil {
+		return otel.GetTracerProvider()
+	}
+	// Create resource with different service name
+	res, err := resource.New(ctx,
+		resource.WithAttributes(
+			semconv.ServiceNameKey.String("llm-d-kv-cache"),
+		),
+	)
+	if err != nil {
+		return otel.GetTracerProvider()
+	}
+	return trace.NewTracerProvider(
+		trace.WithBatcher(exporter),
+		trace.WithResource(res),
+	)
+}