MCS connection scaling interop tests for Java

android-interop-testing/build.gradle

@@ -17,6 +17,7 @@ android {
                 srcDirs += "${projectDir}/../interop-testing/src/main/java/"
                 setIncludes(["io/grpc/android/integrationtest/**",
                              "io/grpc/testing/integration/AbstractInteropTest.java",
+                             "io/grpc/testing/integration/TestCases.java",
                              "io/grpc/testing/integration/TestServiceImpl.java",
                              "io/grpc/testing/integration/Util.java"])
             }

interop-testing/src/main/java/io/grpc/testing/integration/TestCases.java

@@ -59,7 +59,8 @@ public enum TestCases {
   RPC_SOAK("sends 'soak_iterations' large_unary rpcs in a loop, each on the same channel"),
   CHANNEL_SOAK("sends 'soak_iterations' large_unary rpcs in a loop, each on a new channel"),
   ORCA_PER_RPC("report backend metrics per query"),
-  ORCA_OOB("report backend metrics out-of-band");
+  ORCA_OOB("report backend metrics out-of-band"),
+  MCS_CS("max concurrent streaming connection scaling");
 
   private final String description;
 

interop-testing/src/main/java/io/grpc/testing/integration/TestServiceClient.java

@@ -70,6 +70,7 @@
 import io.grpc.testing.integration.Messages.TestOrcaReport;
 import java.io.File;
 import java.io.FileInputStream;
+import java.io.IOException;
 import java.io.InputStream;
 import java.nio.charset.Charset;
 import java.util.Arrays;
@@ -563,7 +564,46 @@ private void runTest(TestCases testCase) throws Exception {
         tester.testOrcaOob();
         break;
       }
-
+
+      case MCS_CS: {
+        ChannelCredentials channelCredentials;
+        if (useTls) {
+          if (!useTestCa) {
+            channelCredentials = TlsChannelCredentials.create();
+          } else {
+            try {
+              channelCredentials = TlsChannelCredentials.newBuilder()
+                  .trustManager(TlsTesting.loadCert("ca.pem"))
+                  .build();
+            } catch (Exception ex) {
+              throw new RuntimeException(ex);
+            }
+          }
+        } else {
+          channelCredentials = InsecureChannelCredentials.create();
+        }
+        ManagedChannelBuilder<?> channelBuilder;
+        if (serverPort == 0) {
+          channelBuilder = Grpc.newChannelBuilder(serverHost, channelCredentials);
+        } else {
+          channelBuilder =
+              Grpc.newChannelBuilderForAddress(serverHost, serverPort, channelCredentials);
+        }
+        if (serverHostOverride != null) {
+          channelBuilder.overrideAuthority(serverHostOverride);
+        }
+        channelBuilder.disableServiceConfigLookUp();
+        try {
+          @SuppressWarnings("unchecked")
+          Map<String, ?> serviceConfigMap = (Map<String, ?>) JsonParser.parse(
+              "{\"connection_scaling\":{\"max_connections_per_subchannel\": 2}}");
+          channelBuilder.defaultServiceConfig(serviceConfigMap);
+        } catch (IOException e) {
+          throw new RuntimeException(e);
+        }
+        tester.testMcs(TestServiceGrpc.newStub(channelBuilder.build()));
+        break;
+      }
       default:
         throw new IllegalArgumentException("Unknown test case: " + testCase);
     }
@@ -596,6 +636,7 @@ private ClientInterceptor maybeCreateAdditionalMetadataInterceptor(
   }
 
   private class Tester extends AbstractInteropTest {
+
     @Override
     protected ManagedChannelBuilder<?> createChannelBuilder() {
       boolean useGeneric = false;
@@ -979,31 +1020,16 @@ public void testOrcaOob() throws Exception {
           .build();
 
       final int retryLimit = 5;
-      BlockingQueue<Object> queue = new LinkedBlockingQueue<>();
-      final Object lastItem = new Object();
+      StreamingOutputCallResponseObserver streamingOutputCallResponseObserver =
+          new StreamingOutputCallResponseObserver();
       StreamObserver<StreamingOutputCallRequest> streamObserver =
-          asyncStub.fullDuplexCall(new StreamObserver<StreamingOutputCallResponse>() {
-
-            @Override
-            public void onNext(StreamingOutputCallResponse value) {
-              queue.add(value);
-            }
-
-            @Override
-            public void onError(Throwable t) {
-              queue.add(t);
-            }
-
-            @Override
-            public void onCompleted() {
-              queue.add(lastItem);
-            }
-          });
+          asyncStub.fullDuplexCall(streamingOutputCallResponseObserver);
 
       streamObserver.onNext(StreamingOutputCallRequest.newBuilder()
           .setOrcaOobReport(answer)
           .addResponseParameters(ResponseParameters.newBuilder().setSize(1).build()).build());
-      assertThat(queue.take()).isInstanceOf(StreamingOutputCallResponse.class);
+      assertThat(streamingOutputCallResponseObserver.take())
+          .isInstanceOf(StreamingOutputCallResponse.class);
       int i = 0;
       for (; i < retryLimit; i++) {
         Thread.sleep(1000);
@@ -1016,7 +1042,8 @@ public void onCompleted() {
       streamObserver.onNext(StreamingOutputCallRequest.newBuilder()
           .setOrcaOobReport(answer2)
           .addResponseParameters(ResponseParameters.newBuilder().setSize(1).build()).build());
-      assertThat(queue.take()).isInstanceOf(StreamingOutputCallResponse.class);
+      assertThat(streamingOutputCallResponseObserver.take())
+          .isInstanceOf(StreamingOutputCallResponse.class);
 
       for (i = 0; i < retryLimit; i++) {
         Thread.sleep(1000);
@@ -1027,7 +1054,7 @@ public void onCompleted() {
       }
       assertThat(i).isLessThan(retryLimit);
       streamObserver.onCompleted();
-      assertThat(queue.take()).isSameInstanceAs(lastItem);
+      assertThat(streamingOutputCallResponseObserver.verifiedCompleted()).isTrue();
     }
 
     @Override
@@ -1054,6 +1081,84 @@ protected ServerBuilder<?> getHandshakerServerBuilder() {
     protected int operationTimeoutMillis() {
       return 15000;
     }
+
+    class StreamingOutputCallResponseObserver implements
+        StreamObserver<StreamingOutputCallResponse> {
+      private final Object lastItem = new Object();
+      private final BlockingQueue<Object> queue = new LinkedBlockingQueue<>();
+
+      @Override
+      public void onNext(StreamingOutputCallResponse value) {
+        queue.add(value);
+      }
+
+      @Override
+      public void onError(Throwable t) {
+        queue.add(t);
+      }
+
+      @Override
+      public void onCompleted() {
+        queue.add(lastItem);
+      }
+
+      Object take() throws InterruptedException {
+        return queue.take();
+      }
+
+      boolean verifiedCompleted() throws InterruptedException {
+        return queue.take() == lastItem;
+      }
+    }
+
+    public void testMcs(TestServiceGrpc.TestServiceStub asyncStub) throws Exception {
+      StreamingOutputCallResponseObserver responseObserver1 =
+          new StreamingOutputCallResponseObserver();
+      StreamObserver<StreamingOutputCallRequest> streamObserver1 =
+          asyncStub.fullDuplexCall(responseObserver1);
+      StreamingOutputCallRequest request = StreamingOutputCallRequest.newBuilder()
+          .addResponseParameters(ResponseParameters.newBuilder()
+              .setSendClientSocketAddressInResponse(
+                  Messages.BoolValue.newBuilder().setValue(true).build())
+              .build())
+          .build();
+      streamObserver1.onNext(request);
+      Object responseObj = responseObserver1.take();
+      StreamingOutputCallResponse callResponse = (StreamingOutputCallResponse) responseObj;
+      String clientSocketAddressInCall1 = callResponse.getClientSocketAddress();
+      assertThat(clientSocketAddressInCall1).isNotEmpty();
+
+      StreamingOutputCallResponseObserver responseObserver2 =
+          new StreamingOutputCallResponseObserver();
+      StreamObserver<StreamingOutputCallRequest> streamObserver2 =
+          asyncStub.fullDuplexCall(responseObserver2);
+      streamObserver2.onNext(request);
+      callResponse = (StreamingOutputCallResponse) responseObserver2.take();
+      String clientSocketAddressInCall2 = callResponse.getClientSocketAddress();
+
+      assertThat(clientSocketAddressInCall1).isEqualTo(clientSocketAddressInCall2);
+
+      // The first connection is at max rpc call count of 2, so the 3rd rpc will cause a new
+      // connection to be created in the same subchannel and not get queued.
+      StreamingOutputCallResponseObserver responseObserver3 =
+          new StreamingOutputCallResponseObserver();
+      StreamObserver<StreamingOutputCallRequest> streamObserver3 =
+          asyncStub.fullDuplexCall(responseObserver3);
+      streamObserver3.onNext(request);
+      callResponse = (StreamingOutputCallResponse) responseObserver3.take();
+      String clientSocketAddressInCall3 = callResponse.getClientSocketAddress();
+
+      // This assertion is currently failing because connection scaling when MCS limit has been
+      // reached is not yet implemented in gRPC Java.
+      assertThat(clientSocketAddressInCall3).isNotEqualTo(clientSocketAddressInCall1);
+
+      streamObserver1.onCompleted();
+      assertThat(responseObserver1.verifiedCompleted()).isTrue();
+      streamObserver2.onCompleted();
+      assertThat(responseObserver2.verifiedCompleted()).isTrue();
+      streamObserver3.onCompleted();
+      assertThat(responseObserver3.verifiedCompleted()).isTrue();
+    }
   }
 
   private static String validTestCasesHelpText() {

interop-testing/src/main/java/io/grpc/testing/integration/TestServiceImpl.java

@@ -16,13 +16,18 @@
 
 package io.grpc.testing.integration;
 
+import static io.grpc.Grpc.TRANSPORT_ATTR_REMOTE_ADDR;
+
 import com.google.common.base.Preconditions;
 import com.google.common.collect.Queues;
 import com.google.errorprone.annotations.concurrent.GuardedBy;
 import com.google.protobuf.ByteString;
+import io.grpc.Context;
+import io.grpc.Contexts;
 import io.grpc.ForwardingServerCall.SimpleForwardingServerCall;
 import io.grpc.Metadata;
 import io.grpc.ServerCall;
+import io.grpc.ServerCall.Listener;
 import io.grpc.ServerCallHandler;
 import io.grpc.ServerInterceptor;
 import io.grpc.Status;
@@ -42,10 +47,12 @@
 import io.grpc.testing.integration.Messages.StreamingOutputCallResponse;
 import io.grpc.testing.integration.Messages.TestOrcaReport;
 import io.grpc.testing.integration.TestServiceGrpc.AsyncService;
+import java.net.SocketAddress;
 import java.util.ArrayDeque;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Queue;
@@ -61,8 +68,8 @@
  * sent in response streams.
  */
 public class TestServiceImpl implements io.grpc.BindableService, AsyncService {
+  static Context.Key<SocketAddress> PEER_ADDRESS_CONTEXT_KEY = Context.key("peer-address");
   private final Random random = new Random();
-
   private final ScheduledExecutorService executor;
   private final ByteString compressableBuffer;
   private final MetricRecorder metricRecorder;
@@ -235,9 +242,27 @@ public void onNext(StreamingOutputCallRequest request) {
               .asRuntimeException());
           return;
         }
+        if (whetherSendClientSocketAddressInResponse(request)) {
+          responseObserver.onNext(
+              StreamingOutputCallResponse.newBuilder()
+                  .setClientSocketAddress(PEER_ADDRESS_CONTEXT_KEY.get().toString())
+                  .build());
+          return;
+        }
         dispatcher.enqueue(toChunkQueue(request));
       }
 
+      private boolean whetherSendClientSocketAddressInResponse(StreamingOutputCallRequest request) {
+        Iterator<ResponseParameters> responseParametersIterator =
+            request.getResponseParametersList().iterator();
+        while (responseParametersIterator.hasNext()) {
+          if (responseParametersIterator.next().getSendClientSocketAddressInResponse().getValue()) {
+            return true;
+          }
+        }
+        return false;
+      }
+
       @Override
       public void onCompleted() {
         if (oobTestLocked) {
@@ -507,7 +532,8 @@ public static List<ServerInterceptor> interceptors() {
     return Arrays.asList(
         echoRequestHeadersInterceptor(Util.METADATA_KEY),
         echoRequestMetadataInHeaders(Util.ECHO_INITIAL_METADATA_KEY),
-        echoRequestMetadataInTrailers(Util.ECHO_TRAILING_METADATA_KEY));
+        echoRequestMetadataInTrailers(Util.ECHO_TRAILING_METADATA_KEY),
+        new McsScalingTestcaseInterceptor());
   }
 
   /**
@@ -539,6 +565,22 @@ public void close(Status status, Metadata trailers) {
     };
   }
 
+  static class McsScalingTestcaseInterceptor implements ServerInterceptor {
+    @Override
+    public <ReqT, RespT> Listener<ReqT> interceptCall(ServerCall<ReqT, RespT> call,
+        Metadata headers, ServerCallHandler<ReqT, RespT> next) {
+      SocketAddress peerAddress = call.getAttributes().get(TRANSPORT_ATTR_REMOTE_ADDR);
+
+      // Create a new context with the peer address value
+      Context newContext = Context.current().withValue(PEER_ADDRESS_CONTEXT_KEY, peerAddress);
+      try {
+        return Contexts.interceptCall(newContext, call, headers, next);
+      } catch (Exception ex) {
+        throw new RuntimeException(ex);
+      }
+    }
+  }
+
   /**
    * Echoes request headers with the specified key(s) from a client into response headers only.
    */

interop-testing/src/main/java/io/grpc/testing/integration/TestServiceServer.java

@@ -75,6 +75,7 @@ public void run() {
   private int port = 8080;
   private boolean useTls = true;
   private boolean useAlts = false;
+  private boolean setMcsLimit = false;
 
   private ScheduledExecutorService executor;
   private Server server;
@@ -118,6 +119,10 @@ void parseArgs(String[] args) {
           usage = true;
           break;
         }
+      } else if ("set_max_concurrent_streams_limit".equals(key)) {
+        setMcsLimit = Boolean.parseBoolean(value);
+        // TODO: Make Netty server builder usable for IPV6 as well (not limited to MCS handling)
+        addressType = Util.AddressType.IPV4; // To use NettyServerBuilder
       } else {
         System.err.println("Unknown argument: " + key);
         usage = true;
@@ -141,6 +146,8 @@ void parseArgs(String[] args) {
               + "\n                        for testing. Only effective when --use_alts=true."
               + "\n  --address_type=IPV4|IPV6|IPV4_IPV6"
               + "\n                        What type of addresses to listen on. Default IPV4_IPV6"
+              + "\n  --set_max_concurrent_streams_limit"
+              + "\n                        Whether to set the maximum concurrent streams limit"
       );
       System.exit(1);
     }
@@ -186,6 +193,9 @@ void start() throws Exception {
         if (v4Address != null && !v4Address.equals(localV4Address)) {
           ((NettyServerBuilder) serverBuilder).addListenAddress(v4Address);
         }
+        if (setMcsLimit) {
+          ((NettyServerBuilder) serverBuilder).maxConcurrentCallsPerConnection(2);
+        }
         break;
       case IPV6:
         List<SocketAddress> v6Addresses = Util.getV6Addresses(port);

interop-testing/src/main/proto/grpc/testing/messages.proto

@@ -159,6 +159,10 @@ message ResponseParameters {
   // implement the full compression tests by introspecting the call to verify
   // the response's compression status.
   BoolValue compressed = 3;
+
+  // Whether to request the server to send the requesting client's socket
+  // address in the response.
+  BoolValue send_client_socket_address_in_response = 4;
 }
 
 // Server-streaming request.
@@ -186,6 +190,9 @@ message StreamingOutputCallRequest {
 message StreamingOutputCallResponse {
   // Payload to increase response size.
   Payload payload = 1;
+
+  // The client's socket address if requested.
+  string client_socket_address = 2;
 }
 
 // For reconnect interop test only.

interop-testing/src/test/java/io/grpc/testing/integration/TestCasesTest.java

@@ -67,7 +67,8 @@ public void testCaseNamesShouldMapToEnums() {
       "cancel_after_first_response",
       "timeout_on_sleeping_server",
       "orca_per_rpc",
-      "orca_oob"
+      "orca_oob",
+      "mcs_cs",
     };
 
     // additional test cases