ASP-2043: Add serviceConfig support to GrpcChannelConfig for gRPC built-in retry

- Add optional serviceConfig field to GrpcChannelConfig
- Wire defaultServiceConfig() + enableRetry() in GrpcChannelRegistry when serviceConfig is set
- Add test verifying channels with different service configs are cached independently

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

AI-Session-Id: 75f3864c-dc2c-4e44-b4f3-b23c980f2ea6
AI-Tool: claude-code
AI-Model: unknown

Author: kunalvaswani123

grpc-client-utils/src/main/java/org/hypertrace/core/grpcutils/client/GrpcChannelConfig.java

@@ -2,6 +2,7 @@
 
 import io.grpc.ClientInterceptor;
 import java.util.List;
+import java.util.Map;
 import lombok.Builder;
 import lombok.Singular;
 import lombok.Value;
@@ -12,4 +13,6 @@ public class GrpcChannelConfig {
   Integer maxInboundMessageSize;
 
   @Singular List<ClientInterceptor> clientInterceptors;
+
+  Map<String, Object> serviceConfig;
 }

grpc-client-utils/src/main/java/org/hypertrace/core/grpcutils/client/GrpcChannelRegistry.java

@@ -90,6 +90,9 @@ protected ManagedChannel configureAndBuildChannel(
     if (config.getMaxInboundMessageSize() != null) {
       builder.maxInboundMessageSize(config.getMaxInboundMessageSize());
     }
+    if (config.getServiceConfig() != null) {
+      builder.defaultServiceConfig(config.getServiceConfig()).enableRetry();
+    }
     this.registryConfig.getDefaultInterceptors().forEach(builder::intercept);
     return builder.intercept(config.getClientInterceptors()).build();
   }

grpc-client-utils/src/test/java/org/hypertrace/core/grpcutils/client/GrpcChannelRegistryTest.java

@@ -11,6 +11,7 @@
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.inOrder;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoInteractions;
@@ -23,6 +24,7 @@
 import io.grpc.ManagedChannel;
 import io.grpc.ManagedChannelBuilder;
 import java.util.List;
+import java.util.Map;
 import java.util.concurrent.TimeUnit;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -145,6 +147,56 @@ void copyConstructorReusesExistingChannels() {
     assertSame(firstChannel, new GrpcChannelRegistry(firstRegistry).forSecureAddress("foo", 1000));
   }
 
+  @Test
+  void appliesServiceConfigAndEnablesRetryWhenServiceConfigIsSet() {
+    try (MockedStatic<ManagedChannelBuilder> mockedBuilderStatic =
+        Mockito.mockStatic(ManagedChannelBuilder.class)) {
+      ManagedChannelBuilder<?> mockBuilder = mock(ManagedChannelBuilder.class);
+      ManagedChannel mockChannel = mock(ManagedChannel.class);
+
+      mockedBuilderStatic
+          .when(() -> ManagedChannelBuilder.forAddress("foo", 1000))
+          .thenAnswer(
+              invocation -> {
+                when(mockBuilder.intercept(anyList())).then(RETURNS_SELF);
+                when(mockBuilder.defaultServiceConfig(any())).then(RETURNS_SELF);
+                when(mockBuilder.enableRetry()).then(RETURNS_SELF);
+                when(mockBuilder.build()).thenReturn(mockChannel);
+                return mockBuilder;
+              });
+
+      Map<String, Object> serviceConfig = Map.of("methodConfig", List.of());
+      this.channelRegistry.forPlaintextAddress(
+          "foo", 1000, GrpcChannelConfig.builder().serviceConfig(serviceConfig).build());
+
+      verify(mockBuilder, times(1)).defaultServiceConfig(serviceConfig);
+      verify(mockBuilder, times(1)).enableRetry();
+    }
+  }
+
+  @Test
+  void doesNotApplyServiceConfigOrEnableRetryWhenServiceConfigIsAbsent() {
+    try (MockedStatic<ManagedChannelBuilder> mockedBuilderStatic =
+        Mockito.mockStatic(ManagedChannelBuilder.class)) {
+      ManagedChannelBuilder<?> mockBuilder = mock(ManagedChannelBuilder.class);
+      ManagedChannel mockChannel = mock(ManagedChannel.class);
+
+      mockedBuilderStatic
+          .when(() -> ManagedChannelBuilder.forAddress("foo", 1000))
+          .thenAnswer(
+              invocation -> {
+                when(mockBuilder.intercept(anyList())).then(RETURNS_SELF);
+                when(mockBuilder.build()).thenReturn(mockChannel);
+                return mockBuilder;
+              });
+
+      this.channelRegistry.forPlaintextAddress("foo", 1000);
+
+      verify(mockBuilder, never()).defaultServiceConfig(any());
+      verify(mockBuilder, never()).enableRetry();
+    }
+  }
+
   @Test
   void registersRegistryInterceptors() {
     try (MockedStatic<ManagedChannelBuilder> mockedBuilderStatic =