commit d374b26b6891255556ab4476f4ce22871219ae76
author Eric Anderson <ejona@google.com> Mon Jun 23 13:19:55 2025 -0700
committer Eric Anderson <ejona@google.com> Tue Jun 24 14:56:16 2025 +0000
tree 362dba7ad9f7d0707683d4c885e47216a4e36f6b
parent f99b2aaef884da0fbe4ade56df98c8a037e974a3

xds: Disable LOGICAL_DNS in XdsDepMan until used

ClusterResolverLb is still doing DNS itself, so disable it in XdsDepMan
until that migration has finished. EDS is fine in XdsDepman, because
XdsClient will share the result with ClusterResolverLb.

xds/src/main/java/io/grpc/xds/XdsDependencyManager.java

diff --git a/xds/src/main/java/io/grpc/xds/XdsDependencyManager.java b/xds/src/main/java/io/grpc/xds/XdsDependencyManager.java
index cc419e6..5ed3821 100644
--- a/xds/src/main/java/io/grpc/xds/XdsDependencyManager.java
+++ b/xds/src/main/java/io/grpc/xds/XdsDependencyManager.java
@@ -82,6 +82,9 @@
   private static final Locality LOGICAL_DNS_CLUSTER_LOCALITY = Locality.create("", "", "");
 
   private static final int MAX_CLUSTER_RECURSION_DEPTH = 16; // Specified by gRFC A37
+
+  static boolean enableLogicalDns = false;
+
   private final String listenerName;
   private final XdsClient xdsClient;
   private final SynchronizationContext syncContext;
@@ -363,9 +366,14 @@
         }
         break;
       case LOGICAL_DNS:
-        TrackedWatcher<List<EquivalentAddressGroup>> dnsWatcher =
-            tracer.getWatcher(DNS_TYPE, cdsUpdate.dnsHostName());
-        child = new EndpointConfig(dnsToEdsUpdate(dnsWatcher.getData(), cdsUpdate.dnsHostName()));
+        if (enableLogicalDns) {
+          TrackedWatcher<List<EquivalentAddressGroup>> dnsWatcher =
+              tracer.getWatcher(DNS_TYPE, cdsUpdate.dnsHostName());
+          child = new EndpointConfig(dnsToEdsUpdate(dnsWatcher.getData(), cdsUpdate.dnsHostName()));
+        } else {
+          child = new EndpointConfig(StatusOr.fromStatus(
+              Status.INTERNAL.withDescription("Logical DNS in dependency manager unsupported")));
+        }
         break;
       default:
         child = new EndpointConfig(StatusOr.fromStatus(Status.UNAVAILABLE.withDescription(
@@ -806,7 +814,9 @@
           addEdsWatcher(getEdsServiceName());
           break;
         case LOGICAL_DNS:
-          addDnsWatcher(update.dnsHostName());
+          if (enableLogicalDns) {
+            addDnsWatcher(update.dnsHostName());
+          }
           break;
         case AGGREGATE:
           update.prioritizedClusterNames()

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

diff --git a/xds/src/test/java/io/grpc/xds/XdsDependencyManagerTest.java b/xds/src/test/java/io/grpc/xds/XdsDependencyManagerTest.java
index 5a897de..fca7b52 100644
--- a/xds/src/test/java/io/grpc/xds/XdsDependencyManagerTest.java
+++ b/xds/src/test/java/io/grpc/xds/XdsDependencyManagerTest.java
@@ -152,6 +152,7 @@
 
   private XdsDependencyManager xdsDependencyManager = new XdsDependencyManager(
       xdsClient, syncContext, serverName, serverName, nameResolverArgs);
+  private boolean savedEnableLogicalDns;
 
   @Before
   public void setUp() throws Exception {
@@ -168,6 +169,8 @@
     testWatcher = new TestWatcher();
     xdsConfigWatcher = mock(TestWatcher.class, delegatesTo(testWatcher));
     defaultXdsConfig = XdsTestUtils.getDefaultXdsConfig(serverName);
+
+    savedEnableLogicalDns = XdsDependencyManager.enableLogicalDns;
   }
 
   @After
@@ -180,6 +183,8 @@
     assertThat(adsEnded.get()).isTrue();
     assertThat(lrsEnded.get()).isTrue();
     assertThat(fakeClock.getPendingTasks()).isEmpty();
+
+    XdsDependencyManager.enableLogicalDns = savedEnableLogicalDns;
   }
 
   @Test
@@ -749,6 +754,7 @@
 
   @Test
   public void testLogicalDns_success() {
+    XdsDependencyManager.enableLogicalDns = true;
     FakeSocketAddress fakeAddress = new FakeSocketAddress();
     nameResolverRegistry.register(new FakeNameResolverProvider(
         "dns:///dns.example.com:1111", fakeAddress));
@@ -789,6 +795,7 @@
 
   @Test
   public void testLogicalDns_noDnsNr() {
+    XdsDependencyManager.enableLogicalDns = true;
     Cluster cluster = Cluster.newBuilder()
         .setName(CLUSTER_NAME)
         .setType(Cluster.DiscoveryType.LOGICAL_DNS)