add db client metrics

Author: zeitlinger

instrumentation-api-incubator/src/main/java/io/opentelemetry/instrumentation/api/incubator/semconv/db/DbClientMetrics.java

@@ -32,7 +32,7 @@ public final class DbClientMetrics implements OperationListener {
 
   private static final double NANOS_PER_S = TimeUnit.SECONDS.toNanos(1);
 
-  private static final ContextKey<State> DB_CLIENT_REQUEST_METRICS_STATE =
+  private static final ContextKey<State> DB_CLIENT_OPERATION_METRICS_STATE =
       ContextKey.named("db-client-metrics-state");
 
   private static final Logger logger = Logger.getLogger(DbClientMetrics.class.getName());
@@ -63,13 +63,13 @@ private DbClientMetrics(Meter meter) {
   @Override
   public Context onStart(Context context, Attributes startAttributes, long startNanos) {
     return context.with(
-        DB_CLIENT_REQUEST_METRICS_STATE,
+        DB_CLIENT_OPERATION_METRICS_STATE,
         new AutoValue_DbClientMetrics_State(startAttributes, startNanos));
   }
 
   @Override
   public void onEnd(Context context, Attributes endAttributes, long endNanos) {
-    State state = context.get(DB_CLIENT_REQUEST_METRICS_STATE);
+    State state = context.get(DB_CLIENT_OPERATION_METRICS_STATE);
     if (state == null) {
       logger.log(
           FINE,

instrumentation-api-incubator/src/test/java/io/opentelemetry/instrumentation/api/incubator/semconv/db/DbClientMetricsTest.java

@@ -36,7 +36,7 @@ void collectsMetrics() {
 
     OperationListener listener = DbClientMetrics.get().create(meterProvider.get("test"));
 
-    Attributes requestAttributes =
+    Attributes operationAttributes =
         Attributes.builder()
             .put(DbClientCommonAttributesExtractor.DB_SYSTEM, "myDb")
             .put(SqlClientAttributesExtractor.DB_COLLECTION_NAME, "table")
@@ -64,7 +64,7 @@ void collectsMetrics() {
                         TraceFlags.getSampled(),
                         TraceState.getDefault())));
 
-    Context context1 = listener.onStart(parent, requestAttributes, nanos(100));
+    Context context1 = listener.onStart(parent, operationAttributes, nanos(100));
 
     assertThat(metricReader.collectAllMetrics()).isEmpty();