otel: plumb optional labels other than disconnect_error

Author: AgraVator

api/src/main/java/io/grpc/LoadBalancer.java

@@ -135,6 +135,12 @@ public abstract class LoadBalancer {
   public static final Attributes.Key<Boolean> IS_PETIOLE_POLICY =
       Attributes.Key.create("io.grpc.IS_PETIOLE_POLICY");
 
+  /**
+   * The name of the locality that this EquivalentAddressGroup is in.
+   */
+  public static final Attributes.Key<String> ATTR_LOCALITY_NAME =
+      Attributes.Key.create("io.grpc.lb.locality");
+
   /**
    * A picker that always returns an erring pick.
    *

core/src/main/java/io/grpc/internal/InternalSubchannel.java

@@ -588,8 +588,13 @@ public Attributes filterTransport(Attributes attributes) {
     @Override
     public void transportReady() {
       channelLogger.log(ChannelLogLevel.INFO, "READY");
-      subchannelMetrics.recordConnectionAttemptSucceeded(
-          buildLabelSet(null, extractSecurityLevel()));
+      subchannelMetrics.recordConnectionAttemptSucceeded(buildLabelSet(
+          addressIndex.getCurrentEagAttributes().get(NameResolver.ATTR_BACKEND_SERVICE),
+          addressIndex.getCurrentEagAttributes().get(LoadBalancer.ATTR_LOCALITY_NAME),
+          null,
+          extractSecurityLevel(
+              addressIndex.getCurrentEagAttributes().get(GrpcAttributes.ATTR_SECURITY_LEVEL))
+      ));
       syncContext.execute(new Runnable() {
         @Override
         public void run() {
@@ -626,7 +631,11 @@ public void transportShutdown(final Status s) {
       channelLogger.log(
           ChannelLogLevel.INFO, "{0} SHUTDOWN with {1}", transport.getLogId(), printShortStatus(s));
       shutdownInitiated = true;
-      subchannelMetrics.recordConnectionAttemptFailed(buildLabelSet("Peer Pressure", null));
+      subchannelMetrics.recordConnectionAttemptFailed(buildLabelSet(
+          addressIndex.getCurrentEagAttributes().get(NameResolver.ATTR_BACKEND_SERVICE),
+          addressIndex.getCurrentEagAttributes().get(LoadBalancer.ATTR_LOCALITY_NAME),
+          null, null
+      ));
       syncContext.execute(new Runnable() {
         @Override
         public void run() {
@@ -681,8 +690,13 @@ public void transportTerminated() {
       for (ClientTransportFilter filter : transportFilters) {
         filter.transportTerminated(transport.getAttributes());
       }
-      subchannelMetrics.recordDisconnection(buildLabelSet("Peer Pressure",
-          null));
+      subchannelMetrics.recordDisconnection(buildLabelSet(
+          addressIndex.getCurrentEagAttributes().get(NameResolver.ATTR_BACKEND_SERVICE),
+          addressIndex.getCurrentEagAttributes().get(LoadBalancer.ATTR_LOCALITY_NAME),
+          "Peer Pressure",
+          extractSecurityLevel(
+              addressIndex.getCurrentEagAttributes().get(GrpcAttributes.ATTR_SECURITY_LEVEL))
+      ));
       syncContext.execute(new Runnable() {
         @Override
         public void run() {
@@ -873,13 +887,14 @@ private String printShortStatus(Status status) {
     return buffer.toString();
   }
 
-  private OtelMetricsAttributes buildLabelSet(String disconnectError, String secLevel) {
+  private OtelMetricsAttributes buildLabelSet(String backendService, String locality,
+                                              String disconnectError, String securityLevel) {
     return new OtelMetricsAttributes(
         target,
         backendService,
         locality,
         disconnectError,
-        secLevel != null ? secLevel : securityLevel
+        securityLevel
     );
   }