fix: mark spans volatile and append /attempt to attempt span name

Author: jinseopkim0

sdk-platform-java/gax-java/gax/src/main/java/com/google/api/gax/tracing/OpenTelemetryTracingTracer.java

@@ -53,8 +53,8 @@ class OpenTelemetryTracingTracer implements ApiTracer {
   private final String attemptSpanName;
   private final String operationSpanName;
   private final ApiTracerContext apiTracerContext;
-  private @Nullable Span operationSpan;
-  private @Nullable Span attemptSpan;
+  private volatile @Nullable Span operationSpan;
+  private volatile @Nullable Span attemptSpan;
 
   @Override
   public void injectTraceContext(java.util.Map<String, String> carrier) {
@@ -134,21 +134,23 @@ private static String resolveOperationSpanName(String attemptSpanName) {
   }
 
   private static String resolveAttemptSpanName(ApiTracerContext apiTracerContext) {
+    String baseName;
     if (apiTracerContext.transport() == ApiTracerContext.Transport.GRPC
         && !Strings.isNullOrEmpty(apiTracerContext.fullMethodName())) {
       // gRPC Uses the full method name as span name.
-      return apiTracerContext.fullMethodName();
+      baseName = apiTracerContext.fullMethodName();
     } else if (apiTracerContext.httpMethod() == null
         || apiTracerContext.httpPathTemplate() == null) {
       // HTTP method name without necessary components defaults to the full method name
-      return apiTracerContext.fullMethodName() != null
-          ? apiTracerContext.fullMethodName()
-          : "attempt";
+      baseName =
+          apiTracerContext.fullMethodName() != null ? apiTracerContext.fullMethodName() : "attempt";
     } else {
       // We construct the span name with HTTP method and path template.
-      return String.format(
-          "%s %s", apiTracerContext.httpMethod(), apiTracerContext.httpPathTemplate());
+      baseName =
+          String.format(
+              "%s %s", apiTracerContext.httpMethod(), apiTracerContext.httpPathTemplate());
     }
+    return "attempt".equals(baseName) ? "attempt" : baseName + "/attempt";
   }
 
   private void buildAttributes() {