Tracing updates

sdk/core/azure-core-tracing-opentelemetry/src/main/java/com/azure/core/tracing/opentelemetry/OpenTelemetryTracer.java

@@ -311,7 +311,7 @@ private Builder getSpanBuilder(String spanName, Context context) {
     private <T> T getOrDefault(Context context, String key, T defaultValue, Class<T> clazz) {
         final Optional<Object> optional = context.getData(key);
         final Object result = optional.filter(value -> clazz.isAssignableFrom(value.getClass())).orElseGet(() -> {
-            logger.warning("Could not extract key '{}' of type '{}' from context.", key, clazz);
+            logger.verbose("Could not extract key '{}' of type '{}' from context.", key, clazz);
             return defaultValue;
         });
 

sdk/core/azure-core/src/main/java/com/azure/core/util/tracing/TracerProxy.java

@@ -5,8 +5,8 @@
 import com.azure.core.util.Context;
 
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
+import java.util.Optional;
 import java.util.ServiceLoader;
 
 /**
@@ -17,14 +17,13 @@
  */
 public final class TracerProxy {
 
-    private static final List<Tracer> TRACERS;
+    private static Tracer TRACER;
+
     static {
         ServiceLoader<Tracer> serviceLoader = ServiceLoader.load(Tracer.class);
-        List<Tracer> tracers = new ArrayList<>();
-        for (Tracer tracer : serviceLoader) {
-            tracers.add(tracer);
+        if (serviceLoader != null) {
+            TRACER = serviceLoader.iterator().next();
         }
-        TRACERS = Collections.unmodifiableList(tracers);
     }
 
     private TracerProxy() {
@@ -33,7 +32,7 @@ private TracerProxy() {
 
     /**
      * A new tracing span is created for each {@link Tracer tracer} plugged into the SDK.
-     *
+     * <p>
      * The {@code context} will be checked for information about a parent span. If a parent span is found, the new span
      * will be added as a child. Otherwise, the parent span will be created and added to the {@code context} and any
      * downstream {@code start()} calls will use the created span as the parent.
@@ -44,12 +43,10 @@ private TracerProxy() {
      * @return An updated {@link Context} object.
      */
     public static Context start(String methodName, Context context) {
-        Context local = context;
-        for (Tracer tracer : TRACERS) {
-            local = tracer.start(methodName, local);
+        if (TRACER == null) {
+            return context;
         }
-
-        return local;
+        return TRACER.start(methodName, context);
     }
 
     /**
@@ -61,7 +58,10 @@ public static Context start(String methodName, Context context) {
      * @param context Additional metadata that is passed through the call stack.
      */
     public static void setAttribute(String key, String value, Context context) {
-        TRACERS.forEach(tracer -> tracer.setAttribute(key, value, context));
+        if (TRACER == null) {
+            return;
+        }
+        TRACER.setAttribute(key, value, context);
     }
 
     /**
@@ -72,7 +72,10 @@ public static void setAttribute(String key, String value, Context context) {
      * @param context Additional metadata that is passed through the call stack.
      */
     public static void end(int responseCode, Throwable error, Context context) {
-        TRACERS.forEach(tracer -> tracer.end(responseCode, error, context));
+        if (TRACER == null) {
+            return;
+        }
+        TRACER.end(responseCode, error, context);
     }
 
     /**
@@ -84,11 +87,9 @@ public static void end(int responseCode, Throwable error, Context context) {
      * @return An updated {@link Context} object.
      */
     public static Context setSpanName(String spanName, Context context) {
-        Context local = context;
-        for (Tracer tracer : TRACERS) {
-            local = tracer.setSpanName(spanName, context);
+        if (TRACER == null) {
+            return context;
         }
-
-        return local;
+        return TRACER.setSpanName(spanName, context);
     }
 }