xds: Remember nonces for unknown types (1.68.x backport)

xds/src/main/java/io/grpc/xds/client/ControlPlaneClient.java

@@ -266,7 +266,7 @@ XdsResourceType<?> fromTypeUrl(String typeUrl) {
   private class AdsStream implements EventHandler<DiscoveryResponse> {
     private boolean responseReceived;
     private boolean closed;
-    // Response nonce for the most recently received discovery responses of each resource type.
+    // Response nonce for the most recently received discovery responses of each resource type URL.
     // Client initiated requests start response nonce with empty string.
     // Nonce in each response is echoed back in the following ACK/NACK request. It is
     // used for management server to identify which response the client is ACKing/NACking.
@@ -275,7 +275,7 @@ private class AdsStream implements EventHandler<DiscoveryResponse> {
     // map; nonces are only discarded once the stream closes because xds_protocol says "the
     // management server should not send a DiscoveryResponse for any DiscoveryRequest that has a
     // stale nonce."
-    private final Map<XdsResourceType<?>, String> respNonces = new HashMap<>();
+    private final Map<String, String> respNonces = new HashMap<>();
     private final StreamingCall<DiscoveryRequest, DiscoveryResponse> call;
     private final MethodDescriptor<DiscoveryRequest, DiscoveryResponse> methodDescriptor =
         AggregatedDiscoveryServiceGrpc.getStreamAggregatedResourcesMethod();
@@ -323,7 +323,7 @@ void sendDiscoveryRequest(XdsResourceType<?> type, String versionInfo,
     final void sendDiscoveryRequest(XdsResourceType<?> type, Collection<String> resources) {
       logger.log(XdsLogLevel.INFO, "Sending {0} request for resources: {1}", type, resources);
       sendDiscoveryRequest(type, versions.getOrDefault(type, ""), resources,
-          respNonces.getOrDefault(type, ""), null);
+          respNonces.getOrDefault(type.typeUrl(), ""), null);
     }
 
     @Override
@@ -336,6 +336,7 @@ public void onRecvMessage(DiscoveryResponse response) {
       syncContext.execute(new Runnable() {
         @Override
         public void run() {
+          respNonces.put(response.getTypeUrl(), response.getNonce());
           XdsResourceType<?> type = fromTypeUrl(response.getTypeUrl());
           if (logger.isLoggable(XdsLogLevel.DEBUG)) {
             logger.log(
@@ -371,7 +372,6 @@ final void handleRpcResponse(XdsResourceType<?> type, String versionInfo, List<A
         return;
       }
       responseReceived = true;
-      respNonces.put(type, nonce);
       ProcessingTracker processingTracker = new ProcessingTracker(
           () -> call.startRecvMessage(), syncContext);
       xdsResponseHandler.handleResourceResponse(type, serverInfo, versionInfo, resources, nonce,

xds/src/test/java/io/grpc/xds/GrpcXdsClientImplTestBase.java

@@ -2781,10 +2781,13 @@ public void edsCleanupNonceAfterUnsubscription() {
     xdsClient.cancelXdsResourceWatch(XdsEndpointResource.getInstance(), "A.1", edsResourceWatcher);
     verifySubscribedResourcesMetadataSizes(0, 0, 0, 0);
     call.verifyRequest(EDS, Arrays.asList(), VERSION_1, "0000", NODE);
+    // The control plane can send an updated response for the empty subscription list, with a new
+    // nonce.
+    call.sendResponse(EDS, Arrays.asList(), VERSION_1, "0001");
 
     // When re-subscribing, the version was forgotten but not the nonce
     xdsClient.watchXdsResource(XdsEndpointResource.getInstance(), "A.1", edsResourceWatcher);
-    call.verifyRequest(EDS, "A.1", "", "0000", NODE, Mockito.timeout(2000));
+    call.verifyRequest(EDS, "A.1", "", "0001", NODE, Mockito.timeout(2000));
   }
 
   @Test