HADOOP-7773. Add support for protocol buffer based RPC engine. Contributed by Suresh Srinivas.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1190611 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -89,6 +89,9 @@ Trunk (unreleased changes)
 
     HADOOP-7761. Improve the performance of raw comparisons. (todd)
 
+    HADOOP-7773. Add support for protocol buffer based RPC engine.
+    (suresh)
+
 Release 0.23.0 - Unreleased
 
   INCOMPATIBLE CHANGES

hadoop-common-project/hadoop-common/dev-support/findbugsExcludeFile.xml

@@ -270,4 +270,8 @@
       <!-- backward compatibility -->
       <Bug pattern="NM_SAME_SIMPLE_NAME_AS_SUPERCLASS"/>
     </Match>
+    <Match>
+      <!-- protobuf generated code -->
+      <Class name="org.apache.hadoop.ipc.protobuf.HadoopRpcProtos"/>
+    </Match>
  </FindBugsFilter>

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ipc/ProtobufRpcEngine.java

@@ -0,0 +1,389 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.ipc;
+
+import java.io.Closeable;
+import java.io.DataInput;
+import java.io.DataOutput;
+import java.io.IOException;
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
+import java.net.InetSocketAddress;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+import javax.net.SocketFactory;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.io.Writable;
+import org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto;
+import org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcRequestProto;
+import org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto;
+import org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.ResponseStatus;
+import org.apache.hadoop.security.UserGroupInformation;
+import org.apache.hadoop.security.token.SecretManager;
+import org.apache.hadoop.security.token.TokenIdentifier;
+import org.apache.hadoop.util.StringUtils;
+
+import com.google.common.annotations.VisibleForTesting;
+import com.google.protobuf.BlockingService;
+import com.google.protobuf.Descriptors.MethodDescriptor;
+import com.google.protobuf.InvalidProtocolBufferException;
+import com.google.protobuf.Message;
+import com.google.protobuf.ServiceException;
+
+/**
+ * RPC Engine for for protobuf based RPCs.
+ */
+@InterfaceStability.Evolving
+public class ProtobufRpcEngine implements RpcEngine {
+  private static final Log LOG = LogFactory.getLog(ProtobufRpcEngine.class);
+
+  private static final ClientCache CLIENTS = new ClientCache();
+
+  @Override
+  @SuppressWarnings("unchecked")
+  public <T> ProtocolProxy<T> getProxy(Class<T> protocol, long clientVersion,
+      InetSocketAddress addr, UserGroupInformation ticket, Configuration conf,
+      SocketFactory factory, int rpcTimeout) throws IOException {
+
+    return new ProtocolProxy<T>(protocol, (T) Proxy.newProxyInstance(protocol
+        .getClassLoader(), new Class[] { protocol }, new Invoker(protocol,
+        addr, ticket, conf, factory, rpcTimeout)), false);
+  }
+
+  private static class Invoker implements InvocationHandler, Closeable {
+    private Map<String, Message> returnTypes = new ConcurrentHashMap<String, Message>();
+    private boolean isClosed = false;
+    private Client.ConnectionId remoteId;
+    private Client client;
+
+    public Invoker(Class<?> protocol, InetSocketAddress addr,
+        UserGroupInformation ticket, Configuration conf, SocketFactory factory,
+        int rpcTimeout) throws IOException {
+      this.remoteId = Client.ConnectionId.getConnectionId(addr, protocol,
+          ticket, rpcTimeout, conf);
+      this.client = CLIENTS.getClient(conf, factory,
+          RpcResponseWritable.class);
+    }
+
+    private HadoopRpcRequestProto constructRpcRequest(Method method,
+        Object[] params) throws ServiceException {
+      HadoopRpcRequestProto rpcRequest;
+      HadoopRpcRequestProto.Builder builder = HadoopRpcRequestProto
+          .newBuilder();
+      builder.setMethodName(method.getName());
+
+      if (params.length != 2) { // RpcController + Message
+        throw new ServiceException("Too many parameters for request. Method: ["
+            + method.getName() + "]" + ", Expected: 2, Actual: "
+            + params.length);
+      }
+      if (params[1] == null) {
+        throw new ServiceException("null param while calling Method: ["
+            + method.getName() + "]");
+      }
+
+      Message param = (Message) params[1];
+      builder.setRequest(param.toByteString());
+      rpcRequest = builder.build();
+      return rpcRequest;
+    }
+
+    /**
+     * This is the client side invoker of RPC method. It only throws
+     * ServiceException, since the invocation proxy expects only
+     * ServiceException to be thrown by the method in case protobuf service.
+     * 
+     * ServiceException has the following causes:
+     * <ol>
+     * <li>Exceptions encountered in this methods are thrown as
+     * RpcClientException, wrapped in RemoteException</li>
+     * <li>Remote exceptions are thrown wrapped in RemoteException</li>
+     * </ol>
+     * 
+     * Note that the client calling protobuf RPC methods, must handle
+     * ServiceException by getting the cause from the ServiceException. If the
+     * cause is RemoteException, then unwrap it to get the exception thrown by
+     * the server.
+     */
+    @Override
+    public Object invoke(Object proxy, Method method, Object[] args)
+        throws ServiceException {
+      long startTime = 0;
+      if (LOG.isDebugEnabled()) {
+        startTime = System.currentTimeMillis();
+      }
+
+      HadoopRpcRequestProto rpcRequest = constructRpcRequest(method, args);
+      RpcResponseWritable val = null;
+      try {
+        val = (RpcResponseWritable) client.call(
+            new RpcRequestWritable(rpcRequest), remoteId);
+      } catch (Exception e) {
+        RpcClientException ce = new RpcClientException("Client exception", e);
+        throw new ServiceException(getRemoteException(ce));
+      }
+
+      HadoopRpcResponseProto response = val.message;
+      if (LOG.isDebugEnabled()) {
+        long callTime = System.currentTimeMillis() - startTime;
+        LOG.debug("Call: " + method.getName() + " " + callTime);
+      }
+
+      // Wrap the received message
+      ResponseStatus status = response.getStatus();
+      if (status != ResponseStatus.SUCCESS) {
+        RemoteException re =  new RemoteException(response.getException()
+            .getExceptionName(), response.getException().getStackTrace());
+        re.fillInStackTrace();
+        throw new ServiceException(re);
+      }
+
+      Message prototype = null;
+      try {
+        prototype = getReturnProtoType(method);
+      } catch (Exception e) {
+        throw new ServiceException(e);
+      }
+      Message returnMessage;
+      try {
+        returnMessage = prototype.newBuilderForType()
+            .mergeFrom(response.getResponse()).build();
+      } catch (InvalidProtocolBufferException e) {
+        RpcClientException ce = new RpcClientException("Client exception", e);
+        throw new ServiceException(getRemoteException(ce));
+      }
+      return returnMessage;
+    }
+
+    public void close() throws IOException {
+      if (!isClosed) {
+        isClosed = true;
+        CLIENTS.stopClient(client);
+      }
+    }
+
+    private Message getReturnProtoType(Method method) throws Exception {
+      if (returnTypes.containsKey(method.getName())) {
+        return returnTypes.get(method.getName());
+      }
+      
+      Class<?> returnType = method.getReturnType();
+      Method newInstMethod = returnType.getMethod("getDefaultInstance");
+      newInstMethod.setAccessible(true);
+      Message prototype = (Message) newInstMethod.invoke(null, (Object[]) null);
+      returnTypes.put(method.getName(), prototype);
+      return prototype;
+    }
+  }
+
+  @Override
+  public Object[] call(Method method, Object[][] params,
+      InetSocketAddress[] addrs, UserGroupInformation ticket, Configuration conf) {
+    throw new UnsupportedOperationException();
+  }
+
+  /**
+   * Writable Wrapper for Protocol Buffer Requests
+   */
+  private static class RpcRequestWritable implements Writable {
+    HadoopRpcRequestProto message;
+
+    @SuppressWarnings("unused")
+    public RpcRequestWritable() {
+    }
+
+    RpcRequestWritable(HadoopRpcRequestProto message) {
+      this.message = message;
+    }
+
+    @Override
+    public void write(DataOutput out) throws IOException {
+      out.writeInt(message.toByteArray().length);
+      out.write(message.toByteArray());
+    }
+
+    @Override
+    public void readFields(DataInput in) throws IOException {
+      int length = in.readInt();
+      byte[] bytes = new byte[length];
+      in.readFully(bytes);
+      message = HadoopRpcRequestProto.parseFrom(bytes);
+    }
+  }
+
+  /**
+   * Writable Wrapper for Protocol Buffer Responses
+   */
+  private static class RpcResponseWritable implements Writable {
+    HadoopRpcResponseProto message;
+
+    @SuppressWarnings("unused")
+    public RpcResponseWritable() {
+    }
+
+    public RpcResponseWritable(HadoopRpcResponseProto message) {
+      this.message = message;
+    }
+
+    @Override
+    public void write(DataOutput out) throws IOException {
+      out.writeInt(message.toByteArray().length);
+      out.write(message.toByteArray());
+    }
+
+    @Override
+    public void readFields(DataInput in) throws IOException {
+      int length = in.readInt();
+      byte[] bytes = new byte[length];
+      in.readFully(bytes);
+      message = HadoopRpcResponseProto.parseFrom(bytes);
+    }
+  }
+
+  @VisibleForTesting
+  @InterfaceAudience.Private
+  @InterfaceStability.Unstable
+  static Client getClient(Configuration conf) {
+    return CLIENTS.getClient(conf, SocketFactory.getDefault(),
+        RpcResponseWritable.class);
+  }
+  
+
+  @Override
+  public RPC.Server getServer(Class<?> protocol, Object instance,
+      String bindAddress, int port, int numHandlers, int numReaders,
+      int queueSizePerHandler, boolean verbose, Configuration conf,
+      SecretManager<? extends TokenIdentifier> secretManager)
+      throws IOException {
+    return new Server(instance, conf, bindAddress, port, numHandlers,
+        numReaders, queueSizePerHandler, verbose, secretManager);
+  }
+  
+  private static RemoteException getRemoteException(Exception e) {
+    return new RemoteException(e.getClass().getName(),
+        StringUtils.stringifyException(e));
+  }
+
+  public static class Server extends RPC.Server {
+    private BlockingService service;
+    private boolean verbose;
+
+    private static String classNameBase(String className) {
+      String[] names = className.split("\\.", -1);
+      if (names == null || names.length == 0) {
+        return className;
+      }
+      return names[names.length - 1];
+    }
+
+    /**
+     * Construct an RPC server.
+     * 
+     * @param instance the instance whose methods will be called
+     * @param conf the configuration to use
+     * @param bindAddress the address to bind on to listen for connection
+     * @param port the port to listen for connections on
+     * @param numHandlers the number of method handler threads to run
+     * @param verbose whether each call should be logged
+     */
+    public Server(Object instance, Configuration conf, String bindAddress,
+        int port, int numHandlers, int numReaders, int queueSizePerHandler,
+        boolean verbose, SecretManager<? extends TokenIdentifier> secretManager)
+        throws IOException {
+      super(bindAddress, port, RpcRequestWritable.class, numHandlers,
+          numReaders, queueSizePerHandler, conf, classNameBase(instance
+              .getClass().getName()), secretManager);
+      this.service = (BlockingService) instance;
+      this.verbose = verbose;
+    }
+
+    /**
+     * This is a server side method, which is invoked over RPC. On success
+     * the return response has protobuf response payload. On failure, the
+     * exception name and the stack trace are return in the resposne. See {@link HadoopRpcResponseProto}
+     * 
+     * In this method there three types of exceptions possible and they are
+     * returned in response as follows.
+     * <ol>
+     * <li> Exceptions encountered in this method that are returned as {@link RpcServerException} </li>
+     * <li> Exceptions thrown by the service is wrapped in ServiceException. In that
+     * this method returns in response the exception thrown by the service.</li>
+     * <li> Other exceptions thrown by the service. They are returned as
+     * it is.</li>
+     * </ol>
+     */
+    @Override
+    public Writable call(String protocol, Writable writableRequest,
+        long receiveTime) throws IOException {
+      RpcRequestWritable request = (RpcRequestWritable) writableRequest;
+      HadoopRpcRequestProto rpcRequest = request.message;
+      String methodName = rpcRequest.getMethodName();
+      if (verbose)
+        LOG.info("Call: protocol=" + protocol + ", method=" + methodName);
+      MethodDescriptor methodDescriptor = service.getDescriptorForType()
+          .findMethodByName(methodName);
+      if (methodDescriptor == null) {
+        String msg = "Unknown method " + methodName + " called on " + protocol
+            + " protocol.";
+        LOG.warn(msg);
+        return handleException(new RpcServerException(msg));
+      }
+      Message prototype = service.getRequestPrototype(methodDescriptor);
+      Message param = prototype.newBuilderForType()
+          .mergeFrom(rpcRequest.getRequest()).build();
+      Message result;
+      try {
+        result = service.callBlockingMethod(methodDescriptor, null, param);
+      } catch (ServiceException e) {
+        Throwable cause = e.getCause();
+        return handleException(cause != null ? cause : e);
+      } catch (Exception e) {
+        return handleException(e);
+      }
+
+      HadoopRpcResponseProto response = constructProtoSpecificRpcSuccessResponse(result);
+      return new RpcResponseWritable(response);
+    }
+
+    private RpcResponseWritable handleException(Throwable e) {
+      HadoopRpcExceptionProto exception = HadoopRpcExceptionProto.newBuilder()
+          .setExceptionName(e.getClass().getName())
+          .setStackTrace(StringUtils.stringifyException(e)).build();
+      HadoopRpcResponseProto response = HadoopRpcResponseProto.newBuilder()
+          .setStatus(ResponseStatus.ERRROR).setException(exception).build();
+      return new RpcResponseWritable(response);
+    }
+
+    private HadoopRpcResponseProto constructProtoSpecificRpcSuccessResponse(
+        Message message) {
+      HadoopRpcResponseProto res = HadoopRpcResponseProto.newBuilder()
+          .setResponse(message.toByteString())
+          .setStatus(ResponseStatus.SUCCESS)
+          .build();
+      return res;
+    }
+  }
+}

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ipc/RpcServerException.java

@@ -25,10 +25,9 @@ public class RpcServerException extends RpcException {
 
   /**
    * Constructs exception with the specified detail message.
-   * 
-   * @param messages detailed message.
+   * @param message detailed message.
    */
-  RpcServerException(final String message) {
+  public RpcServerException(final String message) {
     super(message);
   }
   
@@ -36,12 +35,11 @@ public class RpcServerException extends RpcException {
    * Constructs exception with the specified detail message and cause.
    * 
    * @param message message.
-   * @param cause that cause this exception
    * @param cause the cause (can be retried by the {@link #getCause()} method).
    *          (A <tt>null</tt> value is permitted, and indicates that the cause
    *          is nonexistent or unknown.)
    */
-  RpcServerException(final String message, final Throwable cause) {
+  public RpcServerException(final String message, final Throwable cause) {
     super(message, cause);
   }
 }

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ipc/protobuf/HadoopRpcProtos.java

@@ -0,0 +1,1759 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: hadoop_rpc.proto
+
+package org.apache.hadoop.ipc.protobuf;
+
+public final class HadoopRpcProtos {
+  private HadoopRpcProtos() {}
+  public static void registerAllExtensions(
+      com.google.protobuf.ExtensionRegistry registry) {
+  }
+  public interface HadoopRpcRequestProtoOrBuilder
+      extends com.google.protobuf.MessageOrBuilder {
+    
+    // required string methodName = 1;
+    boolean hasMethodName();
+    String getMethodName();
+    
+    // optional bytes request = 2;
+    boolean hasRequest();
+    com.google.protobuf.ByteString getRequest();
+  }
+  public static final class HadoopRpcRequestProto extends
+      com.google.protobuf.GeneratedMessage
+      implements HadoopRpcRequestProtoOrBuilder {
+    // Use HadoopRpcRequestProto.newBuilder() to construct.
+    private HadoopRpcRequestProto(Builder builder) {
+      super(builder);
+    }
+    private HadoopRpcRequestProto(boolean noInit) {}
+    
+    private static final HadoopRpcRequestProto defaultInstance;
+    public static HadoopRpcRequestProto getDefaultInstance() {
+      return defaultInstance;
+    }
+    
+    public HadoopRpcRequestProto getDefaultInstanceForType() {
+      return defaultInstance;
+    }
+    
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.internal_static_HadoopRpcRequestProto_descriptor;
+    }
+    
+    protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.internal_static_HadoopRpcRequestProto_fieldAccessorTable;
+    }
+    
+    private int bitField0_;
+    // required string methodName = 1;
+    public static final int METHODNAME_FIELD_NUMBER = 1;
+    private java.lang.Object methodName_;
+    public boolean hasMethodName() {
+      return ((bitField0_ & 0x00000001) == 0x00000001);
+    }
+    public String getMethodName() {
+      java.lang.Object ref = methodName_;
+      if (ref instanceof String) {
+        return (String) ref;
+      } else {
+        com.google.protobuf.ByteString bs = 
+            (com.google.protobuf.ByteString) ref;
+        String s = bs.toStringUtf8();
+        if (com.google.protobuf.Internal.isValidUtf8(bs)) {
+          methodName_ = s;
+        }
+        return s;
+      }
+    }
+    private com.google.protobuf.ByteString getMethodNameBytes() {
+      java.lang.Object ref = methodName_;
+      if (ref instanceof String) {
+        com.google.protobuf.ByteString b = 
+            com.google.protobuf.ByteString.copyFromUtf8((String) ref);
+        methodName_ = b;
+        return b;
+      } else {
+        return (com.google.protobuf.ByteString) ref;
+      }
+    }
+    
+    // optional bytes request = 2;
+    public static final int REQUEST_FIELD_NUMBER = 2;
+    private com.google.protobuf.ByteString request_;
+    public boolean hasRequest() {
+      return ((bitField0_ & 0x00000002) == 0x00000002);
+    }
+    public com.google.protobuf.ByteString getRequest() {
+      return request_;
+    }
+    
+    private void initFields() {
+      methodName_ = "";
+      request_ = com.google.protobuf.ByteString.EMPTY;
+    }
+    private byte memoizedIsInitialized = -1;
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized != -1) return isInitialized == 1;
+      
+      if (!hasMethodName()) {
+        memoizedIsInitialized = 0;
+        return false;
+      }
+      memoizedIsInitialized = 1;
+      return true;
+    }
+    
+    public void writeTo(com.google.protobuf.CodedOutputStream output)
+                        throws java.io.IOException {
+      getSerializedSize();
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        output.writeBytes(1, getMethodNameBytes());
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        output.writeBytes(2, request_);
+      }
+      getUnknownFields().writeTo(output);
+    }
+    
+    private int memoizedSerializedSize = -1;
+    public int getSerializedSize() {
+      int size = memoizedSerializedSize;
+      if (size != -1) return size;
+    
+      size = 0;
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(1, getMethodNameBytes());
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(2, request_);
+      }
+      size += getUnknownFields().getSerializedSize();
+      memoizedSerializedSize = size;
+      return size;
+    }
+    
+    private static final long serialVersionUID = 0L;
+    @java.lang.Override
+    protected java.lang.Object writeReplace()
+        throws java.io.ObjectStreamException {
+      return super.writeReplace();
+    }
+    
+    @java.lang.Override
+    public boolean equals(final java.lang.Object obj) {
+      if (obj == this) {
+       return true;
+      }
+      if (!(obj instanceof org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcRequestProto)) {
+        return super.equals(obj);
+      }
+      org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcRequestProto other = (org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcRequestProto) obj;
+      
+      boolean result = true;
+      result = result && (hasMethodName() == other.hasMethodName());
+      if (hasMethodName()) {
+        result = result && getMethodName()
+            .equals(other.getMethodName());
+      }
+      result = result && (hasRequest() == other.hasRequest());
+      if (hasRequest()) {
+        result = result && getRequest()
+            .equals(other.getRequest());
+      }
+      result = result &&
+          getUnknownFields().equals(other.getUnknownFields());
+      return result;
+    }
+    
+    @java.lang.Override
+    public int hashCode() {
+      int hash = 41;
+      hash = (19 * hash) + getDescriptorForType().hashCode();
+      if (hasMethodName()) {
+        hash = (37 * hash) + METHODNAME_FIELD_NUMBER;
+        hash = (53 * hash) + getMethodName().hashCode();
+      }
+      if (hasRequest()) {
+        hash = (37 * hash) + REQUEST_FIELD_NUMBER;
+        hash = (53 * hash) + getRequest().hashCode();
+      }
+      hash = (29 * hash) + getUnknownFields().hashCode();
+      return hash;
+    }
+    
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcRequestProto parseFrom(
+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcRequestProto parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcRequestProto parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcRequestProto parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcRequestProto parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcRequestProto parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcRequestProto parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      Builder builder = newBuilder();
+      if (builder.mergeDelimitedFrom(input)) {
+        return builder.buildParsed();
+      } else {
+        return null;
+      }
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+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
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+        org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcRequestProto result = buildPartial();
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+      public Builder mergeFrom(com.google.protobuf.Message other) {
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+      public Builder mergeFrom(
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+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
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+      public Builder setMethodName(String value) {
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+  bitField0_ |= 0x00000001;
+        methodName_ = value;
+        onChanged();
+        return this;
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+      public Builder clearMethodName() {
+        bitField0_ = (bitField0_ & ~0x00000001);
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+        return this;
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+        request_ = value;
+        onChanged();
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+        bitField0_ = (bitField0_ & ~0x00000002);
+        request_ = getDefaultInstance().getRequest();
+        onChanged();
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+      extends com.google.protobuf.MessageOrBuilder {
+    
+    // optional string exceptionName = 1;
+    boolean hasExceptionName();
+    String getExceptionName();
+    
+    // optional string stackTrace = 2;
+    boolean hasStackTrace();
+    String getStackTrace();
+  }
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+      implements HadoopRpcExceptionProtoOrBuilder {
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+    private HadoopRpcExceptionProto(Builder builder) {
+      super(builder);
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+    private HadoopRpcExceptionProto(boolean noInit) {}
+    
+    private static final HadoopRpcExceptionProto defaultInstance;
+    public static HadoopRpcExceptionProto getDefaultInstance() {
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+    public HadoopRpcExceptionProto getDefaultInstanceForType() {
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+    
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+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data).buildParsed();
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+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data, extensionRegistry)
+               .buildParsed();
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+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data).buildParsed();
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+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data, extensionRegistry)
+               .buildParsed();
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+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      Builder builder = newBuilder();
+      if (builder.mergeDelimitedFrom(input)) {
+        return builder.buildParsed();
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+      }
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+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      Builder builder = newBuilder();
+      if (builder.mergeDelimitedFrom(input, extensionRegistry)) {
+        return builder.buildParsed();
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+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input, extensionRegistry)
+               .buildParsed();
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+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto prototype) {
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+    }
+    public Builder toBuilder() { return newBuilder(this); }
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+    @java.lang.Override
+    protected Builder newBuilderForType(
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+      private Builder() {
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+      
+      public org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto build() {
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+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
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+      
+      private org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto buildParsed()
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(
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+        return result;
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+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto) {
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+          return this;
+        }
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+      public Builder mergeFrom(org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto other) {
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+        if (other.hasExceptionName()) {
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+          throws java.io.IOException {
+        com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder(
+            this.getUnknownFields());
+        while (true) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              this.setUnknownFields(unknownFields.build());
+              onChanged();
+              return this;
+            default: {
+              if (!parseUnknownField(input, unknownFields,
+                                     extensionRegistry, tag)) {
+                this.setUnknownFields(unknownFields.build());
+                onChanged();
+                return this;
+              }
+              break;
+            }
+            case 10: {
+              bitField0_ |= 0x00000001;
+              exceptionName_ = input.readBytes();
+              break;
+            }
+            case 18: {
+              bitField0_ |= 0x00000002;
+              stackTrace_ = input.readBytes();
+              break;
+            }
+          }
+        }
+      }
+      
+      private int bitField0_;
+      
+      // optional string exceptionName = 1;
+      private java.lang.Object exceptionName_ = "";
+      public boolean hasExceptionName() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      public String getExceptionName() {
+        java.lang.Object ref = exceptionName_;
+        if (!(ref instanceof String)) {
+          String s = ((com.google.protobuf.ByteString) ref).toStringUtf8();
+          exceptionName_ = s;
+          return s;
+        } else {
+          return (String) ref;
+        }
+      }
+      public Builder setExceptionName(String value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000001;
+        exceptionName_ = value;
+        onChanged();
+        return this;
+      }
+      public Builder clearExceptionName() {
+        bitField0_ = (bitField0_ & ~0x00000001);
+        exceptionName_ = getDefaultInstance().getExceptionName();
+        onChanged();
+        return this;
+      }
+      void setExceptionName(com.google.protobuf.ByteString value) {
+        bitField0_ |= 0x00000001;
+        exceptionName_ = value;
+        onChanged();
+      }
+      
+      // optional string stackTrace = 2;
+      private java.lang.Object stackTrace_ = "";
+      public boolean hasStackTrace() {
+        return ((bitField0_ & 0x00000002) == 0x00000002);
+      }
+      public String getStackTrace() {
+        java.lang.Object ref = stackTrace_;
+        if (!(ref instanceof String)) {
+          String s = ((com.google.protobuf.ByteString) ref).toStringUtf8();
+          stackTrace_ = s;
+          return s;
+        } else {
+          return (String) ref;
+        }
+      }
+      public Builder setStackTrace(String value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000002;
+        stackTrace_ = value;
+        onChanged();
+        return this;
+      }
+      public Builder clearStackTrace() {
+        bitField0_ = (bitField0_ & ~0x00000002);
+        stackTrace_ = getDefaultInstance().getStackTrace();
+        onChanged();
+        return this;
+      }
+      void setStackTrace(com.google.protobuf.ByteString value) {
+        bitField0_ |= 0x00000002;
+        stackTrace_ = value;
+        onChanged();
+      }
+      
+      // @@protoc_insertion_point(builder_scope:HadoopRpcExceptionProto)
+    }
+    
+    static {
+      defaultInstance = new HadoopRpcExceptionProto(true);
+      defaultInstance.initFields();
+    }
+    
+    // @@protoc_insertion_point(class_scope:HadoopRpcExceptionProto)
+  }
+  
+  public interface HadoopRpcResponseProtoOrBuilder
+      extends com.google.protobuf.MessageOrBuilder {
+    
+    // required .HadoopRpcResponseProto.ResponseStatus status = 1;
+    boolean hasStatus();
+    org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.ResponseStatus getStatus();
+    
+    // optional bytes response = 2;
+    boolean hasResponse();
+    com.google.protobuf.ByteString getResponse();
+    
+    // optional .HadoopRpcExceptionProto exception = 3;
+    boolean hasException();
+    org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto getException();
+    org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProtoOrBuilder getExceptionOrBuilder();
+  }
+  public static final class HadoopRpcResponseProto extends
+      com.google.protobuf.GeneratedMessage
+      implements HadoopRpcResponseProtoOrBuilder {
+    // Use HadoopRpcResponseProto.newBuilder() to construct.
+    private HadoopRpcResponseProto(Builder builder) {
+      super(builder);
+    }
+    private HadoopRpcResponseProto(boolean noInit) {}
+    
+    private static final HadoopRpcResponseProto defaultInstance;
+    public static HadoopRpcResponseProto getDefaultInstance() {
+      return defaultInstance;
+    }
+    
+    public HadoopRpcResponseProto getDefaultInstanceForType() {
+      return defaultInstance;
+    }
+    
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.internal_static_HadoopRpcResponseProto_descriptor;
+    }
+    
+    protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.internal_static_HadoopRpcResponseProto_fieldAccessorTable;
+    }
+    
+    public enum ResponseStatus
+        implements com.google.protobuf.ProtocolMessageEnum {
+      SUCCESS(0, 1),
+      ERRROR(1, 2),
+      ;
+      
+      public static final int SUCCESS_VALUE = 1;
+      public static final int ERRROR_VALUE = 2;
+      
+      
+      public final int getNumber() { return value; }
+      
+      public static ResponseStatus valueOf(int value) {
+        switch (value) {
+          case 1: return SUCCESS;
+          case 2: return ERRROR;
+          default: return null;
+        }
+      }
+      
+      public static com.google.protobuf.Internal.EnumLiteMap<ResponseStatus>
+          internalGetValueMap() {
+        return internalValueMap;
+      }
+      private static com.google.protobuf.Internal.EnumLiteMap<ResponseStatus>
+          internalValueMap =
+            new com.google.protobuf.Internal.EnumLiteMap<ResponseStatus>() {
+              public ResponseStatus findValueByNumber(int number) {
+                return ResponseStatus.valueOf(number);
+              }
+            };
+      
+      public final com.google.protobuf.Descriptors.EnumValueDescriptor
+          getValueDescriptor() {
+        return getDescriptor().getValues().get(index);
+      }
+      public final com.google.protobuf.Descriptors.EnumDescriptor
+          getDescriptorForType() {
+        return getDescriptor();
+      }
+      public static final com.google.protobuf.Descriptors.EnumDescriptor
+          getDescriptor() {
+        return org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.getDescriptor().getEnumTypes().get(0);
+      }
+      
+      private static final ResponseStatus[] VALUES = {
+        SUCCESS, ERRROR, 
+      };
+      
+      public static ResponseStatus valueOf(
+          com.google.protobuf.Descriptors.EnumValueDescriptor desc) {
+        if (desc.getType() != getDescriptor()) {
+          throw new java.lang.IllegalArgumentException(
+            "EnumValueDescriptor is not for this type.");
+        }
+        return VALUES[desc.getIndex()];
+      }
+      
+      private final int index;
+      private final int value;
+      
+      private ResponseStatus(int index, int value) {
+        this.index = index;
+        this.value = value;
+      }
+      
+      // @@protoc_insertion_point(enum_scope:HadoopRpcResponseProto.ResponseStatus)
+    }
+    
+    private int bitField0_;
+    // required .HadoopRpcResponseProto.ResponseStatus status = 1;
+    public static final int STATUS_FIELD_NUMBER = 1;
+    private org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.ResponseStatus status_;
+    public boolean hasStatus() {
+      return ((bitField0_ & 0x00000001) == 0x00000001);
+    }
+    public org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.ResponseStatus getStatus() {
+      return status_;
+    }
+    
+    // optional bytes response = 2;
+    public static final int RESPONSE_FIELD_NUMBER = 2;
+    private com.google.protobuf.ByteString response_;
+    public boolean hasResponse() {
+      return ((bitField0_ & 0x00000002) == 0x00000002);
+    }
+    public com.google.protobuf.ByteString getResponse() {
+      return response_;
+    }
+    
+    // optional .HadoopRpcExceptionProto exception = 3;
+    public static final int EXCEPTION_FIELD_NUMBER = 3;
+    private org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto exception_;
+    public boolean hasException() {
+      return ((bitField0_ & 0x00000004) == 0x00000004);
+    }
+    public org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto getException() {
+      return exception_;
+    }
+    public org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProtoOrBuilder getExceptionOrBuilder() {
+      return exception_;
+    }
+    
+    private void initFields() {
+      status_ = org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.ResponseStatus.SUCCESS;
+      response_ = com.google.protobuf.ByteString.EMPTY;
+      exception_ = org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto.getDefaultInstance();
+    }
+    private byte memoizedIsInitialized = -1;
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized != -1) return isInitialized == 1;
+      
+      if (!hasStatus()) {
+        memoizedIsInitialized = 0;
+        return false;
+      }
+      memoizedIsInitialized = 1;
+      return true;
+    }
+    
+    public void writeTo(com.google.protobuf.CodedOutputStream output)
+                        throws java.io.IOException {
+      getSerializedSize();
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        output.writeEnum(1, status_.getNumber());
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        output.writeBytes(2, response_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        output.writeMessage(3, exception_);
+      }
+      getUnknownFields().writeTo(output);
+    }
+    
+    private int memoizedSerializedSize = -1;
+    public int getSerializedSize() {
+      int size = memoizedSerializedSize;
+      if (size != -1) return size;
+    
+      size = 0;
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeEnumSize(1, status_.getNumber());
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(2, response_);
+      }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeMessageSize(3, exception_);
+      }
+      size += getUnknownFields().getSerializedSize();
+      memoizedSerializedSize = size;
+      return size;
+    }
+    
+    private static final long serialVersionUID = 0L;
+    @java.lang.Override
+    protected java.lang.Object writeReplace()
+        throws java.io.ObjectStreamException {
+      return super.writeReplace();
+    }
+    
+    @java.lang.Override
+    public boolean equals(final java.lang.Object obj) {
+      if (obj == this) {
+       return true;
+      }
+      if (!(obj instanceof org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto)) {
+        return super.equals(obj);
+      }
+      org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto other = (org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto) obj;
+      
+      boolean result = true;
+      result = result && (hasStatus() == other.hasStatus());
+      if (hasStatus()) {
+        result = result &&
+            (getStatus() == other.getStatus());
+      }
+      result = result && (hasResponse() == other.hasResponse());
+      if (hasResponse()) {
+        result = result && getResponse()
+            .equals(other.getResponse());
+      }
+      result = result && (hasException() == other.hasException());
+      if (hasException()) {
+        result = result && getException()
+            .equals(other.getException());
+      }
+      result = result &&
+          getUnknownFields().equals(other.getUnknownFields());
+      return result;
+    }
+    
+    @java.lang.Override
+    public int hashCode() {
+      int hash = 41;
+      hash = (19 * hash) + getDescriptorForType().hashCode();
+      if (hasStatus()) {
+        hash = (37 * hash) + STATUS_FIELD_NUMBER;
+        hash = (53 * hash) + hashEnum(getStatus());
+      }
+      if (hasResponse()) {
+        hash = (37 * hash) + RESPONSE_FIELD_NUMBER;
+        hash = (53 * hash) + getResponse().hashCode();
+      }
+      if (hasException()) {
+        hash = (37 * hash) + EXCEPTION_FIELD_NUMBER;
+        hash = (53 * hash) + getException().hashCode();
+      }
+      hash = (29 * hash) + getUnknownFields().hashCode();
+      return hash;
+    }
+    
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto parseFrom(
+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      Builder builder = newBuilder();
+      if (builder.mergeDelimitedFrom(input)) {
+        return builder.buildParsed();
+      } else {
+        return null;
+      }
+    }
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      Builder builder = newBuilder();
+      if (builder.mergeDelimitedFrom(input, extensionRegistry)) {
+        return builder.buildParsed();
+      } else {
+        return null;
+      }
+    }
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input, extensionRegistry)
+               .buildParsed();
+    }
+    
+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto prototype) {
+      return newBuilder().mergeFrom(prototype);
+    }
+    public Builder toBuilder() { return newBuilder(this); }
+    
+    @java.lang.Override
+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+      Builder builder = new Builder(parent);
+      return builder;
+    }
+    public static final class Builder extends
+        com.google.protobuf.GeneratedMessage.Builder<Builder>
+       implements org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProtoOrBuilder {
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.internal_static_HadoopRpcResponseProto_descriptor;
+      }
+      
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.internal_static_HadoopRpcResponseProto_fieldAccessorTable;
+      }
+      
+      // Construct using org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.newBuilder()
+      private Builder() {
+        maybeForceBuilderInitialization();
+      }
+      
+      private Builder(BuilderParent parent) {
+        super(parent);
+        maybeForceBuilderInitialization();
+      }
+      private void maybeForceBuilderInitialization() {
+        if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+          getExceptionFieldBuilder();
+        }
+      }
+      private static Builder create() {
+        return new Builder();
+      }
+      
+      public Builder clear() {
+        super.clear();
+        status_ = org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.ResponseStatus.SUCCESS;
+        bitField0_ = (bitField0_ & ~0x00000001);
+        response_ = com.google.protobuf.ByteString.EMPTY;
+        bitField0_ = (bitField0_ & ~0x00000002);
+        if (exceptionBuilder_ == null) {
+          exception_ = org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto.getDefaultInstance();
+        } else {
+          exceptionBuilder_.clear();
+        }
+        bitField0_ = (bitField0_ & ~0x00000004);
+        return this;
+      }
+      
+      public Builder clone() {
+        return create().mergeFrom(buildPartial());
+      }
+      
+      public com.google.protobuf.Descriptors.Descriptor
+          getDescriptorForType() {
+        return org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.getDescriptor();
+      }
+      
+      public org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto getDefaultInstanceForType() {
+        return org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.getDefaultInstance();
+      }
+      
+      public org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto build() {
+        org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
+      }
+      
+      private org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto buildParsed()
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(
+            result).asInvalidProtocolBufferException();
+        }
+        return result;
+      }
+      
+      public org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto buildPartial() {
+        org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto result = new org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto(this);
+        int from_bitField0_ = bitField0_;
+        int to_bitField0_ = 0;
+        if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+          to_bitField0_ |= 0x00000001;
+        }
+        result.status_ = status_;
+        if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+          to_bitField0_ |= 0x00000002;
+        }
+        result.response_ = response_;
+        if (((from_bitField0_ & 0x00000004) == 0x00000004)) {
+          to_bitField0_ |= 0x00000004;
+        }
+        if (exceptionBuilder_ == null) {
+          result.exception_ = exception_;
+        } else {
+          result.exception_ = exceptionBuilder_.build();
+        }
+        result.bitField0_ = to_bitField0_;
+        onBuilt();
+        return result;
+      }
+      
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto) {
+          return mergeFrom((org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto)other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+      
+      public Builder mergeFrom(org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto other) {
+        if (other == org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.getDefaultInstance()) return this;
+        if (other.hasStatus()) {
+          setStatus(other.getStatus());
+        }
+        if (other.hasResponse()) {
+          setResponse(other.getResponse());
+        }
+        if (other.hasException()) {
+          mergeException(other.getException());
+        }
+        this.mergeUnknownFields(other.getUnknownFields());
+        return this;
+      }
+      
+      public final boolean isInitialized() {
+        if (!hasStatus()) {
+          
+          return false;
+        }
+        return true;
+      }
+      
+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder(
+            this.getUnknownFields());
+        while (true) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              this.setUnknownFields(unknownFields.build());
+              onChanged();
+              return this;
+            default: {
+              if (!parseUnknownField(input, unknownFields,
+                                     extensionRegistry, tag)) {
+                this.setUnknownFields(unknownFields.build());
+                onChanged();
+                return this;
+              }
+              break;
+            }
+            case 8: {
+              int rawValue = input.readEnum();
+              org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.ResponseStatus value = org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.ResponseStatus.valueOf(rawValue);
+              if (value == null) {
+                unknownFields.mergeVarintField(1, rawValue);
+              } else {
+                bitField0_ |= 0x00000001;
+                status_ = value;
+              }
+              break;
+            }
+            case 18: {
+              bitField0_ |= 0x00000002;
+              response_ = input.readBytes();
+              break;
+            }
+            case 26: {
+              org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto.Builder subBuilder = org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto.newBuilder();
+              if (hasException()) {
+                subBuilder.mergeFrom(getException());
+              }
+              input.readMessage(subBuilder, extensionRegistry);
+              setException(subBuilder.buildPartial());
+              break;
+            }
+          }
+        }
+      }
+      
+      private int bitField0_;
+      
+      // required .HadoopRpcResponseProto.ResponseStatus status = 1;
+      private org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.ResponseStatus status_ = org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.ResponseStatus.SUCCESS;
+      public boolean hasStatus() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      public org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.ResponseStatus getStatus() {
+        return status_;
+      }
+      public Builder setStatus(org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.ResponseStatus value) {
+        if (value == null) {
+          throw new NullPointerException();
+        }
+        bitField0_ |= 0x00000001;
+        status_ = value;
+        onChanged();
+        return this;
+      }
+      public Builder clearStatus() {
+        bitField0_ = (bitField0_ & ~0x00000001);
+        status_ = org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.ResponseStatus.SUCCESS;
+        onChanged();
+        return this;
+      }
+      
+      // optional bytes response = 2;
+      private com.google.protobuf.ByteString response_ = com.google.protobuf.ByteString.EMPTY;
+      public boolean hasResponse() {
+        return ((bitField0_ & 0x00000002) == 0x00000002);
+      }
+      public com.google.protobuf.ByteString getResponse() {
+        return response_;
+      }
+      public Builder setResponse(com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000002;
+        response_ = value;
+        onChanged();
+        return this;
+      }
+      public Builder clearResponse() {
+        bitField0_ = (bitField0_ & ~0x00000002);
+        response_ = getDefaultInstance().getResponse();
+        onChanged();
+        return this;
+      }
+      
+      // optional .HadoopRpcExceptionProto exception = 3;
+      private org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto exception_ = org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto.getDefaultInstance();
+      private com.google.protobuf.SingleFieldBuilder<
+          org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto, org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto.Builder, org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProtoOrBuilder> exceptionBuilder_;
+      public boolean hasException() {
+        return ((bitField0_ & 0x00000004) == 0x00000004);
+      }
+      public org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto getException() {
+        if (exceptionBuilder_ == null) {
+          return exception_;
+        } else {
+          return exceptionBuilder_.getMessage();
+        }
+      }
+      public Builder setException(org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto value) {
+        if (exceptionBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          exception_ = value;
+          onChanged();
+        } else {
+          exceptionBuilder_.setMessage(value);
+        }
+        bitField0_ |= 0x00000004;
+        return this;
+      }
+      public Builder setException(
+          org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto.Builder builderForValue) {
+        if (exceptionBuilder_ == null) {
+          exception_ = builderForValue.build();
+          onChanged();
+        } else {
+          exceptionBuilder_.setMessage(builderForValue.build());
+        }
+        bitField0_ |= 0x00000004;
+        return this;
+      }
+      public Builder mergeException(org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto value) {
+        if (exceptionBuilder_ == null) {
+          if (((bitField0_ & 0x00000004) == 0x00000004) &&
+              exception_ != org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto.getDefaultInstance()) {
+            exception_ =
+              org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto.newBuilder(exception_).mergeFrom(value).buildPartial();
+          } else {
+            exception_ = value;
+          }
+          onChanged();
+        } else {
+          exceptionBuilder_.mergeFrom(value);
+        }
+        bitField0_ |= 0x00000004;
+        return this;
+      }
+      public Builder clearException() {
+        if (exceptionBuilder_ == null) {
+          exception_ = org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto.getDefaultInstance();
+          onChanged();
+        } else {
+          exceptionBuilder_.clear();
+        }
+        bitField0_ = (bitField0_ & ~0x00000004);
+        return this;
+      }
+      public org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto.Builder getExceptionBuilder() {
+        bitField0_ |= 0x00000004;
+        onChanged();
+        return getExceptionFieldBuilder().getBuilder();
+      }
+      public org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProtoOrBuilder getExceptionOrBuilder() {
+        if (exceptionBuilder_ != null) {
+          return exceptionBuilder_.getMessageOrBuilder();
+        } else {
+          return exception_;
+        }
+      }
+      private com.google.protobuf.SingleFieldBuilder<
+          org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto, org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto.Builder, org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProtoOrBuilder> 
+          getExceptionFieldBuilder() {
+        if (exceptionBuilder_ == null) {
+          exceptionBuilder_ = new com.google.protobuf.SingleFieldBuilder<
+              org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto, org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto.Builder, org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProtoOrBuilder>(
+                  exception_,
+                  getParentForChildren(),
+                  isClean());
+          exception_ = null;
+        }
+        return exceptionBuilder_;
+      }
+      
+      // @@protoc_insertion_point(builder_scope:HadoopRpcResponseProto)
+    }
+    
+    static {
+      defaultInstance = new HadoopRpcResponseProto(true);
+      defaultInstance.initFields();
+    }
+    
+    // @@protoc_insertion_point(class_scope:HadoopRpcResponseProto)
+  }
+  
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_HadoopRpcRequestProto_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_HadoopRpcRequestProto_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_HadoopRpcExceptionProto_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_HadoopRpcExceptionProto_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_HadoopRpcResponseProto_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_HadoopRpcResponseProto_fieldAccessorTable;
+  
+  public static com.google.protobuf.Descriptors.FileDescriptor
+      getDescriptor() {
+    return descriptor;
+  }
+  private static com.google.protobuf.Descriptors.FileDescriptor
+      descriptor;
+  static {
+    java.lang.String[] descriptorData = {
+      "\n\020hadoop_rpc.proto\"<\n\025HadoopRpcRequestPr" +
+      "oto\022\022\n\nmethodName\030\001 \002(\t\022\017\n\007request\030\002 \001(\014" +
+      "\"D\n\027HadoopRpcExceptionProto\022\025\n\rexception" +
+      "Name\030\001 \001(\t\022\022\n\nstackTrace\030\002 \001(\t\"\272\001\n\026Hadoo" +
+      "pRpcResponseProto\0226\n\006status\030\001 \002(\0162&.Hado" +
+      "opRpcResponseProto.ResponseStatus\022\020\n\010res" +
+      "ponse\030\002 \001(\014\022+\n\texception\030\003 \001(\0132\030.HadoopR" +
+      "pcExceptionProto\")\n\016ResponseStatus\022\013\n\007SU" +
+      "CCESS\020\001\022\n\n\006ERRROR\020\002B4\n\036org.apache.hadoop" +
+      ".ipc.protobufB\017HadoopRpcProtos\240\001\001"
+    };
+    com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner assigner =
+      new com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner() {
+        public com.google.protobuf.ExtensionRegistry assignDescriptors(
+            com.google.protobuf.Descriptors.FileDescriptor root) {
+          descriptor = root;
+          internal_static_HadoopRpcRequestProto_descriptor =
+            getDescriptor().getMessageTypes().get(0);
+          internal_static_HadoopRpcRequestProto_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_HadoopRpcRequestProto_descriptor,
+              new java.lang.String[] { "MethodName", "Request", },
+              org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcRequestProto.class,
+              org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcRequestProto.Builder.class);
+          internal_static_HadoopRpcExceptionProto_descriptor =
+            getDescriptor().getMessageTypes().get(1);
+          internal_static_HadoopRpcExceptionProto_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_HadoopRpcExceptionProto_descriptor,
+              new java.lang.String[] { "ExceptionName", "StackTrace", },
+              org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto.class,
+              org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcExceptionProto.Builder.class);
+          internal_static_HadoopRpcResponseProto_descriptor =
+            getDescriptor().getMessageTypes().get(2);
+          internal_static_HadoopRpcResponseProto_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_HadoopRpcResponseProto_descriptor,
+              new java.lang.String[] { "Status", "Response", "Exception", },
+              org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.class,
+              org.apache.hadoop.ipc.protobuf.HadoopRpcProtos.HadoopRpcResponseProto.Builder.class);
+          return null;
+        }
+      };
+    com.google.protobuf.Descriptors.FileDescriptor
+      .internalBuildGeneratedFileFrom(descriptorData,
+        new com.google.protobuf.Descriptors.FileDescriptor[] {
+        }, assigner);
+  }
+  
+  // @@protoc_insertion_point(outer_class_scope)
+}

hadoop-common-project/hadoop-common/src/proto/hadoop_rpc.proto

@@ -0,0 +1,73 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * These are the messages used by Hadoop RPC to marshal the
+ * request and response in the RPC layer.
+ */
+option java_package = "org.apache.hadoop.ipc.protobuf";
+option java_outer_classname = "HadoopRpcProtos";
+option java_generate_equals_and_hash = true;
+
+/**
+ * Message used to marshal the client request
+ * from RPC client to the RPC server.
+ */
+message HadoopRpcRequestProto {
+  /** Name of the RPC method */
+  required string methodName = 1;
+
+  /** Bytes corresponding to the client protobuf request */
+  optional bytes request = 2;
+}
+
+/**
+ * At the RPC layer, this message is used to indicate
+ * the server side exception the the RPC client.
+ *
+ * Hadoop RPC client throws an exception indicated
+ * by exceptionName with the stackTrace.
+ */
+message HadoopRpcExceptionProto {
+  /** Class name of the exception thrown from the server */
+
+  optional string exceptionName = 1;
+  /** Exception stack trace from the server side */
+  optional string stackTrace = 2;
+}
+
+/**
+ * This message is used to marshal the response from
+ * RPC server to the client.
+ */
+message HadoopRpcResponseProto {
+  /** Status of IPC call */
+  enum ResponseStatus {
+    SUCCESS = 1;
+    ERRROR = 2;
+  }
+
+  required ResponseStatus status = 1;
+
+  // Protobuf response payload from the server, when status is SUCCESS.
+  optional bytes response = 2;
+
+  // Exception when status is ERROR or FATAL
+  optional HadoopRpcExceptionProto exception = 3;
+}
+

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/ipc/TestProtoBufRpc.java

@@ -0,0 +1,123 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.ipc;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto;
+import org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto;
+import org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto;
+import org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto;
+import org.apache.hadoop.ipc.protobuf.TestRpcServiceProtos.TestProtobufRpcProto;
+import org.apache.hadoop.ipc.protobuf.TestRpcServiceProtos.TestProtobufRpcProto.BlockingInterface;
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.google.protobuf.BlockingService;
+import com.google.protobuf.RpcController;
+import com.google.protobuf.ServiceException;
+
+/**
+ * Test for testing protocol buffer based RPC mechanism.
+ * This test depends on test.proto definition of types in src/test/proto
+ * and protobuf service definition from src/test/test_rpc_service.proto
+ */
+public class TestProtoBufRpc {
+  public final static String ADDRESS = "0.0.0.0";
+  public final static int PORT = 0;
+
+  public static class ServerImpl implements BlockingInterface {
+
+    @Override
+    public EmptyResponseProto ping(RpcController unused,
+        EmptyRequestProto request) throws ServiceException {
+      return EmptyResponseProto.newBuilder().build();
+    }
+
+    @Override
+    public EchoResponseProto echo(RpcController unused, EchoRequestProto request)
+        throws ServiceException {
+      return EchoResponseProto.newBuilder().setMessage(request.getMessage())
+          .build();
+    }
+
+    @Override
+    public EmptyResponseProto error(RpcController unused,
+        EmptyRequestProto request) throws ServiceException {
+      throw new ServiceException("error", new RpcServerException("error"));
+    }
+  }
+
+  private static RPC.Server startRPCServer(Configuration conf)
+      throws IOException {
+    // Set RPC engine to protobuf RPC engine
+    RPC.setProtocolEngine(conf, BlockingService.class, ProtobufRpcEngine.class);
+
+    // Create server side implementation
+    ServerImpl serverImpl = new ServerImpl();
+    BlockingService service = TestProtobufRpcProto
+        .newReflectiveBlockingService(serverImpl);
+
+    // Get RPC server for serer side implementation
+    RPC.Server server = RPC.getServer(BlockingService.class, service, ADDRESS,
+        PORT, conf);
+    server.start();
+    return server;
+  }
+
+  private static BlockingInterface getClient(Configuration conf,
+      InetSocketAddress addr) throws IOException {
+    // Set RPC engine to protobuf RPC engine
+    RPC.setProtocolEngine(conf, BlockingInterface.class,
+        ProtobufRpcEngine.class);
+    BlockingInterface client = RPC.getProxy(BlockingInterface.class, 0, addr,
+        conf);
+    return client;
+  }
+
+  @Test
+  public void testProtoBufRpc() throws Exception {
+    Configuration conf = new Configuration();
+    RPC.Server server = startRPCServer(conf);
+    BlockingInterface client = getClient(conf, server.getListenerAddress());
+    
+    // Test ping method
+    EmptyRequestProto emptyRequest = EmptyRequestProto.newBuilder().build();
+    client.ping(null, emptyRequest);
+    
+    // Test echo method
+    EchoRequestProto echoRequest = EchoRequestProto.newBuilder()
+        .setMessage("hello").build();
+    EchoResponseProto echoResponse = client.echo(null, echoRequest);
+    Assert.assertEquals(echoResponse.getMessage(), "hello");
+    
+    // Test error method - it should be thrown as RemoteException
+    try {
+      client.error(null, emptyRequest);
+      Assert.fail("Expected exception is not thrown");
+    } catch (ServiceException e) {
+      RemoteException re = (RemoteException)e.getCause();
+      re.printStackTrace();
+      RpcServerException rse = (RpcServerException) re
+          .unwrapRemoteException(RpcServerException.class);
+      rse.printStackTrace();
+    }
+  }
+}

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/ipc/protobuf/TestProtos.java

@@ -0,0 +1,1525 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: test.proto
+
+package org.apache.hadoop.ipc.protobuf;
+
+public final class TestProtos {
+  private TestProtos() {}
+  public static void registerAllExtensions(
+      com.google.protobuf.ExtensionRegistry registry) {
+  }
+  public interface EmptyRequestProtoOrBuilder
+      extends com.google.protobuf.MessageOrBuilder {
+  }
+  public static final class EmptyRequestProto extends
+      com.google.protobuf.GeneratedMessage
+      implements EmptyRequestProtoOrBuilder {
+    // Use EmptyRequestProto.newBuilder() to construct.
+    private EmptyRequestProto(Builder builder) {
+      super(builder);
+    }
+    private EmptyRequestProto(boolean noInit) {}
+    
+    private static final EmptyRequestProto defaultInstance;
+    public static EmptyRequestProto getDefaultInstance() {
+      return defaultInstance;
+    }
+    
+    public EmptyRequestProto getDefaultInstanceForType() {
+      return defaultInstance;
+    }
+    
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return org.apache.hadoop.ipc.protobuf.TestProtos.internal_static_EmptyRequestProto_descriptor;
+    }
+    
+    protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return org.apache.hadoop.ipc.protobuf.TestProtos.internal_static_EmptyRequestProto_fieldAccessorTable;
+    }
+    
+    private void initFields() {
+    }
+    private byte memoizedIsInitialized = -1;
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized != -1) return isInitialized == 1;
+      
+      memoizedIsInitialized = 1;
+      return true;
+    }
+    
+    public void writeTo(com.google.protobuf.CodedOutputStream output)
+                        throws java.io.IOException {
+      getSerializedSize();
+      getUnknownFields().writeTo(output);
+    }
+    
+    private int memoizedSerializedSize = -1;
+    public int getSerializedSize() {
+      int size = memoizedSerializedSize;
+      if (size != -1) return size;
+    
+      size = 0;
+      size += getUnknownFields().getSerializedSize();
+      memoizedSerializedSize = size;
+      return size;
+    }
+    
+    private static final long serialVersionUID = 0L;
+    @java.lang.Override
+    protected java.lang.Object writeReplace()
+        throws java.io.ObjectStreamException {
+      return super.writeReplace();
+    }
+    
+    @java.lang.Override
+    public boolean equals(final java.lang.Object obj) {
+      if (obj == this) {
+       return true;
+      }
+      if (!(obj instanceof org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto)) {
+        return super.equals(obj);
+      }
+      org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto other = (org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto) obj;
+      
+      boolean result = true;
+      result = result &&
+          getUnknownFields().equals(other.getUnknownFields());
+      return result;
+    }
+    
+    @java.lang.Override
+    public int hashCode() {
+      int hash = 41;
+      hash = (19 * hash) + getDescriptorForType().hashCode();
+      hash = (29 * hash) + getUnknownFields().hashCode();
+      return hash;
+    }
+    
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto parseFrom(
+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      Builder builder = newBuilder();
+      if (builder.mergeDelimitedFrom(input)) {
+        return builder.buildParsed();
+      } else {
+        return null;
+      }
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      Builder builder = newBuilder();
+      if (builder.mergeDelimitedFrom(input, extensionRegistry)) {
+        return builder.buildParsed();
+      } else {
+        return null;
+      }
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input, extensionRegistry)
+               .buildParsed();
+    }
+    
+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto prototype) {
+      return newBuilder().mergeFrom(prototype);
+    }
+    public Builder toBuilder() { return newBuilder(this); }
+    
+    @java.lang.Override
+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+      Builder builder = new Builder(parent);
+      return builder;
+    }
+    public static final class Builder extends
+        com.google.protobuf.GeneratedMessage.Builder<Builder>
+       implements org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProtoOrBuilder {
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.apache.hadoop.ipc.protobuf.TestProtos.internal_static_EmptyRequestProto_descriptor;
+      }
+      
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return org.apache.hadoop.ipc.protobuf.TestProtos.internal_static_EmptyRequestProto_fieldAccessorTable;
+      }
+      
+      // Construct using org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto.newBuilder()
+      private Builder() {
+        maybeForceBuilderInitialization();
+      }
+      
+      private Builder(BuilderParent parent) {
+        super(parent);
+        maybeForceBuilderInitialization();
+      }
+      private void maybeForceBuilderInitialization() {
+        if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+        }
+      }
+      private static Builder create() {
+        return new Builder();
+      }
+      
+      public Builder clear() {
+        super.clear();
+        return this;
+      }
+      
+      public Builder clone() {
+        return create().mergeFrom(buildPartial());
+      }
+      
+      public com.google.protobuf.Descriptors.Descriptor
+          getDescriptorForType() {
+        return org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto.getDescriptor();
+      }
+      
+      public org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto getDefaultInstanceForType() {
+        return org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto.getDefaultInstance();
+      }
+      
+      public org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto build() {
+        org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
+      }
+      
+      private org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto buildParsed()
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(
+            result).asInvalidProtocolBufferException();
+        }
+        return result;
+      }
+      
+      public org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto buildPartial() {
+        org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto result = new org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto(this);
+        onBuilt();
+        return result;
+      }
+      
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto) {
+          return mergeFrom((org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto)other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+      
+      public Builder mergeFrom(org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto other) {
+        if (other == org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto.getDefaultInstance()) return this;
+        this.mergeUnknownFields(other.getUnknownFields());
+        return this;
+      }
+      
+      public final boolean isInitialized() {
+        return true;
+      }
+      
+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder(
+            this.getUnknownFields());
+        while (true) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              this.setUnknownFields(unknownFields.build());
+              onChanged();
+              return this;
+            default: {
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+                this.setUnknownFields(unknownFields.build());
+                onChanged();
+                return this;
+              }
+              break;
+            }
+          }
+        }
+      }
+      
+      
+      // @@protoc_insertion_point(builder_scope:EmptyRequestProto)
+    }
+    
+    static {
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+      defaultInstance.initFields();
+    }
+    
+    // @@protoc_insertion_point(class_scope:EmptyRequestProto)
+  }
+  
+  public interface EmptyResponseProtoOrBuilder
+      extends com.google.protobuf.MessageOrBuilder {
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+  public static final class EmptyResponseProto extends
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+    // Use EmptyResponseProto.newBuilder() to construct.
+    private EmptyResponseProto(Builder builder) {
+      super(builder);
+    }
+    private EmptyResponseProto(boolean noInit) {}
+    
+    private static final EmptyResponseProto defaultInstance;
+    public static EmptyResponseProto getDefaultInstance() {
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+    public EmptyResponseProto getDefaultInstanceForType() {
+      return defaultInstance;
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+    
+    public static final com.google.protobuf.Descriptors.Descriptor
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+    protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
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+    public final boolean isInitialized() {
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+      if (isInitialized != -1) return isInitialized == 1;
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+      getUnknownFields().writeTo(output);
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+      size = 0;
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+      memoizedSerializedSize = size;
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+    protected java.lang.Object writeReplace()
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+    
+    @java.lang.Override
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+       return true;
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+      if (!(obj instanceof org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto)) {
+        return super.equals(obj);
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+      org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto other = (org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto) obj;
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+      boolean result = true;
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+      return result;
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+    @java.lang.Override
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+      int hash = 41;
+      hash = (19 * hash) + getDescriptorForType().hashCode();
+      hash = (29 * hash) + getUnknownFields().hashCode();
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+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto parseFrom(
+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      Builder builder = newBuilder();
+      if (builder.mergeDelimitedFrom(input)) {
+        return builder.buildParsed();
+      } else {
+        return null;
+      }
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      Builder builder = newBuilder();
+      if (builder.mergeDelimitedFrom(input, extensionRegistry)) {
+        return builder.buildParsed();
+      } else {
+        return null;
+      }
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input, extensionRegistry)
+               .buildParsed();
+    }
+    
+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto prototype) {
+      return newBuilder().mergeFrom(prototype);
+    }
+    public Builder toBuilder() { return newBuilder(this); }
+    
+    @java.lang.Override
+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+      Builder builder = new Builder(parent);
+      return builder;
+    }
+    public static final class Builder extends
+        com.google.protobuf.GeneratedMessage.Builder<Builder>
+       implements org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProtoOrBuilder {
+      public static final com.google.protobuf.Descriptors.Descriptor
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+        org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
+      }
+      
+      private org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto buildParsed()
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(
+            result).asInvalidProtocolBufferException();
+        }
+        return result;
+      }
+      
+      public org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto buildPartial() {
+        org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto result = new org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto(this);
+        onBuilt();
+        return result;
+      }
+      
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto) {
+          return mergeFrom((org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto)other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+      
+      public Builder mergeFrom(org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto other) {
+        if (other == org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto.getDefaultInstance()) return this;
+        this.mergeUnknownFields(other.getUnknownFields());
+        return this;
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+      public final boolean isInitialized() {
+        return true;
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+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder(
+            this.getUnknownFields());
+        while (true) {
+          int tag = input.readTag();
+          switch (tag) {
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+              onChanged();
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+                this.setUnknownFields(unknownFields.build());
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+                return this;
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+      
+      
+      // @@protoc_insertion_point(builder_scope:EmptyResponseProto)
+    }
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+      defaultInstance.initFields();
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+    
+    // @@protoc_insertion_point(class_scope:EmptyResponseProto)
+  }
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+      extends com.google.protobuf.MessageOrBuilder {
+    
+    // required string message = 1;
+    boolean hasMessage();
+    String getMessage();
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+  public static final class EchoRequestProto extends
+      com.google.protobuf.GeneratedMessage
+      implements EchoRequestProtoOrBuilder {
+    // Use EchoRequestProto.newBuilder() to construct.
+    private EchoRequestProto(Builder builder) {
+      super(builder);
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+    private EchoRequestProto(boolean noInit) {}
+    
+    private static final EchoRequestProto defaultInstance;
+    public static EchoRequestProto getDefaultInstance() {
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+    }
+    
+    public EchoRequestProto getDefaultInstanceForType() {
+      return defaultInstance;
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+    
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
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+    protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
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+      if (ref instanceof String) {
+        com.google.protobuf.ByteString b = 
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+        return b;
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+      message_ = "";
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+    private byte memoizedIsInitialized = -1;
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized != -1) return isInitialized == 1;
+      
+      if (!hasMessage()) {
+        memoizedIsInitialized = 0;
+        return false;
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+      memoizedIsInitialized = 1;
+      return true;
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+    public void writeTo(com.google.protobuf.CodedOutputStream output)
+                        throws java.io.IOException {
+      getSerializedSize();
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        output.writeBytes(1, getMessageBytes());
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+      getUnknownFields().writeTo(output);
+    }
+    
+    private int memoizedSerializedSize = -1;
+    public int getSerializedSize() {
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+      size = 0;
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        size += com.google.protobuf.CodedOutputStream
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+      size += getUnknownFields().getSerializedSize();
+      memoizedSerializedSize = size;
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+    private static final long serialVersionUID = 0L;
+    @java.lang.Override
+    protected java.lang.Object writeReplace()
+        throws java.io.ObjectStreamException {
+      return super.writeReplace();
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+    
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+      org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto other = (org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto) obj;
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+      if (hasMessage()) {
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+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data).buildParsed();
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+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      Builder builder = newBuilder();
+      if (builder.mergeDelimitedFrom(input)) {
+        return builder.buildParsed();
+      } else {
+        return null;
+      }
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+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      Builder builder = newBuilder();
+      if (builder.mergeDelimitedFrom(input, extensionRegistry)) {
+        return builder.buildParsed();
+      } else {
+        return null;
+      }
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+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input, extensionRegistry)
+               .buildParsed();
+    }
+    
+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto prototype) {
+      return newBuilder().mergeFrom(prototype);
+    }
+    public Builder toBuilder() { return newBuilder(this); }
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+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+      Builder builder = new Builder(parent);
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+       implements org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProtoOrBuilder {
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+        org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto result = buildPartial();
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+        org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto result = new org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto(this);
+        int from_bitField0_ = bitField0_;
+        int to_bitField0_ = 0;
+        if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+          to_bitField0_ |= 0x00000001;
+        }
+        result.message_ = message_;
+        result.bitField0_ = to_bitField0_;
+        onBuilt();
+        return result;
+      }
+      
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto) {
+          return mergeFrom((org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto)other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+      
+      public Builder mergeFrom(org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto other) {
+        if (other == org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto.getDefaultInstance()) return this;
+        if (other.hasMessage()) {
+          setMessage(other.getMessage());
+        }
+        this.mergeUnknownFields(other.getUnknownFields());
+        return this;
+      }
+      
+      public final boolean isInitialized() {
+        if (!hasMessage()) {
+          
+          return false;
+        }
+        return true;
+      }
+      
+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder(
+            this.getUnknownFields());
+        while (true) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              this.setUnknownFields(unknownFields.build());
+              onChanged();
+              return this;
+            default: {
+              if (!parseUnknownField(input, unknownFields,
+                                     extensionRegistry, tag)) {
+                this.setUnknownFields(unknownFields.build());
+                onChanged();
+                return this;
+              }
+              break;
+            }
+            case 10: {
+              bitField0_ |= 0x00000001;
+              message_ = input.readBytes();
+              break;
+            }
+          }
+        }
+      }
+      
+      private int bitField0_;
+      
+      // required string message = 1;
+      private java.lang.Object message_ = "";
+      public boolean hasMessage() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      public String getMessage() {
+        java.lang.Object ref = message_;
+        if (!(ref instanceof String)) {
+          String s = ((com.google.protobuf.ByteString) ref).toStringUtf8();
+          message_ = s;
+          return s;
+        } else {
+          return (String) ref;
+        }
+      }
+      public Builder setMessage(String value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000001;
+        message_ = value;
+        onChanged();
+        return this;
+      }
+      public Builder clearMessage() {
+        bitField0_ = (bitField0_ & ~0x00000001);
+        message_ = getDefaultInstance().getMessage();
+        onChanged();
+        return this;
+      }
+      void setMessage(com.google.protobuf.ByteString value) {
+        bitField0_ |= 0x00000001;
+        message_ = value;
+        onChanged();
+      }
+      
+      // @@protoc_insertion_point(builder_scope:EchoRequestProto)
+    }
+    
+    static {
+      defaultInstance = new EchoRequestProto(true);
+      defaultInstance.initFields();
+    }
+    
+    // @@protoc_insertion_point(class_scope:EchoRequestProto)
+  }
+  
+  public interface EchoResponseProtoOrBuilder
+      extends com.google.protobuf.MessageOrBuilder {
+    
+    // required string message = 1;
+    boolean hasMessage();
+    String getMessage();
+  }
+  public static final class EchoResponseProto extends
+      com.google.protobuf.GeneratedMessage
+      implements EchoResponseProtoOrBuilder {
+    // Use EchoResponseProto.newBuilder() to construct.
+    private EchoResponseProto(Builder builder) {
+      super(builder);
+    }
+    private EchoResponseProto(boolean noInit) {}
+    
+    private static final EchoResponseProto defaultInstance;
+    public static EchoResponseProto getDefaultInstance() {
+      return defaultInstance;
+    }
+    
+    public EchoResponseProto getDefaultInstanceForType() {
+      return defaultInstance;
+    }
+    
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return org.apache.hadoop.ipc.protobuf.TestProtos.internal_static_EchoResponseProto_descriptor;
+    }
+    
+    protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return org.apache.hadoop.ipc.protobuf.TestProtos.internal_static_EchoResponseProto_fieldAccessorTable;
+    }
+    
+    private int bitField0_;
+    // required string message = 1;
+    public static final int MESSAGE_FIELD_NUMBER = 1;
+    private java.lang.Object message_;
+    public boolean hasMessage() {
+      return ((bitField0_ & 0x00000001) == 0x00000001);
+    }
+    public String getMessage() {
+      java.lang.Object ref = message_;
+      if (ref instanceof String) {
+        return (String) ref;
+      } else {
+        com.google.protobuf.ByteString bs = 
+            (com.google.protobuf.ByteString) ref;
+        String s = bs.toStringUtf8();
+        if (com.google.protobuf.Internal.isValidUtf8(bs)) {
+          message_ = s;
+        }
+        return s;
+      }
+    }
+    private com.google.protobuf.ByteString getMessageBytes() {
+      java.lang.Object ref = message_;
+      if (ref instanceof String) {
+        com.google.protobuf.ByteString b = 
+            com.google.protobuf.ByteString.copyFromUtf8((String) ref);
+        message_ = b;
+        return b;
+      } else {
+        return (com.google.protobuf.ByteString) ref;
+      }
+    }
+    
+    private void initFields() {
+      message_ = "";
+    }
+    private byte memoizedIsInitialized = -1;
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized != -1) return isInitialized == 1;
+      
+      if (!hasMessage()) {
+        memoizedIsInitialized = 0;
+        return false;
+      }
+      memoizedIsInitialized = 1;
+      return true;
+    }
+    
+    public void writeTo(com.google.protobuf.CodedOutputStream output)
+                        throws java.io.IOException {
+      getSerializedSize();
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        output.writeBytes(1, getMessageBytes());
+      }
+      getUnknownFields().writeTo(output);
+    }
+    
+    private int memoizedSerializedSize = -1;
+    public int getSerializedSize() {
+      int size = memoizedSerializedSize;
+      if (size != -1) return size;
+    
+      size = 0;
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(1, getMessageBytes());
+      }
+      size += getUnknownFields().getSerializedSize();
+      memoizedSerializedSize = size;
+      return size;
+    }
+    
+    private static final long serialVersionUID = 0L;
+    @java.lang.Override
+    protected java.lang.Object writeReplace()
+        throws java.io.ObjectStreamException {
+      return super.writeReplace();
+    }
+    
+    @java.lang.Override
+    public boolean equals(final java.lang.Object obj) {
+      if (obj == this) {
+       return true;
+      }
+      if (!(obj instanceof org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto)) {
+        return super.equals(obj);
+      }
+      org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto other = (org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto) obj;
+      
+      boolean result = true;
+      result = result && (hasMessage() == other.hasMessage());
+      if (hasMessage()) {
+        result = result && getMessage()
+            .equals(other.getMessage());
+      }
+      result = result &&
+          getUnknownFields().equals(other.getUnknownFields());
+      return result;
+    }
+    
+    @java.lang.Override
+    public int hashCode() {
+      int hash = 41;
+      hash = (19 * hash) + getDescriptorForType().hashCode();
+      if (hasMessage()) {
+        hash = (37 * hash) + MESSAGE_FIELD_NUMBER;
+        hash = (53 * hash) + getMessage().hashCode();
+      }
+      hash = (29 * hash) + getUnknownFields().hashCode();
+      return hash;
+    }
+    
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto parseFrom(
+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return newBuilder().mergeFrom(data, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input, extensionRegistry)
+               .buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      Builder builder = newBuilder();
+      if (builder.mergeDelimitedFrom(input)) {
+        return builder.buildParsed();
+      } else {
+        return null;
+      }
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      Builder builder = newBuilder();
+      if (builder.mergeDelimitedFrom(input, extensionRegistry)) {
+        return builder.buildParsed();
+      } else {
+        return null;
+      }
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input).buildParsed();
+    }
+    public static org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return newBuilder().mergeFrom(input, extensionRegistry)
+               .buildParsed();
+    }
+    
+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto prototype) {
+      return newBuilder().mergeFrom(prototype);
+    }
+    public Builder toBuilder() { return newBuilder(this); }
+    
+    @java.lang.Override
+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+      Builder builder = new Builder(parent);
+      return builder;
+    }
+    public static final class Builder extends
+        com.google.protobuf.GeneratedMessage.Builder<Builder>
+       implements org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProtoOrBuilder {
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return org.apache.hadoop.ipc.protobuf.TestProtos.internal_static_EchoResponseProto_descriptor;
+      }
+      
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return org.apache.hadoop.ipc.protobuf.TestProtos.internal_static_EchoResponseProto_fieldAccessorTable;
+      }
+      
+      // Construct using org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto.newBuilder()
+      private Builder() {
+        maybeForceBuilderInitialization();
+      }
+      
+      private Builder(BuilderParent parent) {
+        super(parent);
+        maybeForceBuilderInitialization();
+      }
+      private void maybeForceBuilderInitialization() {
+        if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+        }
+      }
+      private static Builder create() {
+        return new Builder();
+      }
+      
+      public Builder clear() {
+        super.clear();
+        message_ = "";
+        bitField0_ = (bitField0_ & ~0x00000001);
+        return this;
+      }
+      
+      public Builder clone() {
+        return create().mergeFrom(buildPartial());
+      }
+      
+      public com.google.protobuf.Descriptors.Descriptor
+          getDescriptorForType() {
+        return org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto.getDescriptor();
+      }
+      
+      public org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto getDefaultInstanceForType() {
+        return org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto.getDefaultInstance();
+      }
+      
+      public org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto build() {
+        org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
+      }
+      
+      private org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto buildParsed()
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(
+            result).asInvalidProtocolBufferException();
+        }
+        return result;
+      }
+      
+      public org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto buildPartial() {
+        org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto result = new org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto(this);
+        int from_bitField0_ = bitField0_;
+        int to_bitField0_ = 0;
+        if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+          to_bitField0_ |= 0x00000001;
+        }
+        result.message_ = message_;
+        result.bitField0_ = to_bitField0_;
+        onBuilt();
+        return result;
+      }
+      
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto) {
+          return mergeFrom((org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto)other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+      
+      public Builder mergeFrom(org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto other) {
+        if (other == org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto.getDefaultInstance()) return this;
+        if (other.hasMessage()) {
+          setMessage(other.getMessage());
+        }
+        this.mergeUnknownFields(other.getUnknownFields());
+        return this;
+      }
+      
+      public final boolean isInitialized() {
+        if (!hasMessage()) {
+          
+          return false;
+        }
+        return true;
+      }
+      
+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder(
+            this.getUnknownFields());
+        while (true) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              this.setUnknownFields(unknownFields.build());
+              onChanged();
+              return this;
+            default: {
+              if (!parseUnknownField(input, unknownFields,
+                                     extensionRegistry, tag)) {
+                this.setUnknownFields(unknownFields.build());
+                onChanged();
+                return this;
+              }
+              break;
+            }
+            case 10: {
+              bitField0_ |= 0x00000001;
+              message_ = input.readBytes();
+              break;
+            }
+          }
+        }
+      }
+      
+      private int bitField0_;
+      
+      // required string message = 1;
+      private java.lang.Object message_ = "";
+      public boolean hasMessage() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      public String getMessage() {
+        java.lang.Object ref = message_;
+        if (!(ref instanceof String)) {
+          String s = ((com.google.protobuf.ByteString) ref).toStringUtf8();
+          message_ = s;
+          return s;
+        } else {
+          return (String) ref;
+        }
+      }
+      public Builder setMessage(String value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000001;
+        message_ = value;
+        onChanged();
+        return this;
+      }
+      public Builder clearMessage() {
+        bitField0_ = (bitField0_ & ~0x00000001);
+        message_ = getDefaultInstance().getMessage();
+        onChanged();
+        return this;
+      }
+      void setMessage(com.google.protobuf.ByteString value) {
+        bitField0_ |= 0x00000001;
+        message_ = value;
+        onChanged();
+      }
+      
+      // @@protoc_insertion_point(builder_scope:EchoResponseProto)
+    }
+    
+    static {
+      defaultInstance = new EchoResponseProto(true);
+      defaultInstance.initFields();
+    }
+    
+    // @@protoc_insertion_point(class_scope:EchoResponseProto)
+  }
+  
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_EmptyRequestProto_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_EmptyRequestProto_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_EmptyResponseProto_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_EmptyResponseProto_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_EchoRequestProto_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_EchoRequestProto_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_EchoResponseProto_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_EchoResponseProto_fieldAccessorTable;
+  
+  public static com.google.protobuf.Descriptors.FileDescriptor
+      getDescriptor() {
+    return descriptor;
+  }
+  private static com.google.protobuf.Descriptors.FileDescriptor
+      descriptor;
+  static {
+    java.lang.String[] descriptorData = {
+      "\n\ntest.proto\"\023\n\021EmptyRequestProto\"\024\n\022Emp" +
+      "tyResponseProto\"#\n\020EchoRequestProto\022\017\n\007m" +
+      "essage\030\001 \002(\t\"$\n\021EchoResponseProto\022\017\n\007mes" +
+      "sage\030\001 \002(\tB/\n\036org.apache.hadoop.ipc.prot" +
+      "obufB\nTestProtos\240\001\001"
+    };
+    com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner assigner =
+      new com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner() {
+        public com.google.protobuf.ExtensionRegistry assignDescriptors(
+            com.google.protobuf.Descriptors.FileDescriptor root) {
+          descriptor = root;
+          internal_static_EmptyRequestProto_descriptor =
+            getDescriptor().getMessageTypes().get(0);
+          internal_static_EmptyRequestProto_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_EmptyRequestProto_descriptor,
+              new java.lang.String[] { },
+              org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto.class,
+              org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto.Builder.class);
+          internal_static_EmptyResponseProto_descriptor =
+            getDescriptor().getMessageTypes().get(1);
+          internal_static_EmptyResponseProto_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_EmptyResponseProto_descriptor,
+              new java.lang.String[] { },
+              org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto.class,
+              org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto.Builder.class);
+          internal_static_EchoRequestProto_descriptor =
+            getDescriptor().getMessageTypes().get(2);
+          internal_static_EchoRequestProto_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_EchoRequestProto_descriptor,
+              new java.lang.String[] { "Message", },
+              org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto.class,
+              org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto.Builder.class);
+          internal_static_EchoResponseProto_descriptor =
+            getDescriptor().getMessageTypes().get(3);
+          internal_static_EchoResponseProto_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_EchoResponseProto_descriptor,
+              new java.lang.String[] { "Message", },
+              org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto.class,
+              org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto.Builder.class);
+          return null;
+        }
+      };
+    com.google.protobuf.Descriptors.FileDescriptor
+      .internalBuildGeneratedFileFrom(descriptorData,
+        new com.google.protobuf.Descriptors.FileDescriptor[] {
+        }, assigner);
+  }
+  
+  // @@protoc_insertion_point(outer_class_scope)
+}

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/ipc/protobuf/TestRpcServiceProtos.java

@@ -0,0 +1,395 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: test_rpc_service.proto
+
+package org.apache.hadoop.ipc.protobuf;
+
+public final class TestRpcServiceProtos {
+  private TestRpcServiceProtos() {}
+  public static void registerAllExtensions(
+      com.google.protobuf.ExtensionRegistry registry) {
+  }
+  public static abstract class TestProtobufRpcProto
+      implements com.google.protobuf.Service {
+    protected TestProtobufRpcProto() {}
+    
+    public interface Interface {
+      public abstract void ping(
+          com.google.protobuf.RpcController controller,
+          org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto request,
+          com.google.protobuf.RpcCallback<org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto> done);
+      
+      public abstract void echo(
+          com.google.protobuf.RpcController controller,
+          org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto request,
+          com.google.protobuf.RpcCallback<org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto> done);
+      
+      public abstract void error(
+          com.google.protobuf.RpcController controller,
+          org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto request,
+          com.google.protobuf.RpcCallback<org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto> done);
+      
+    }
+    
+    public static com.google.protobuf.Service newReflectiveService(
+        final Interface impl) {
+      return new TestProtobufRpcProto() {
+        @java.lang.Override
+        public  void ping(
+            com.google.protobuf.RpcController controller,
+            org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto request,
+            com.google.protobuf.RpcCallback<org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto> done) {
+          impl.ping(controller, request, done);
+        }
+        
+        @java.lang.Override
+        public  void echo(
+            com.google.protobuf.RpcController controller,
+            org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto request,
+            com.google.protobuf.RpcCallback<org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto> done) {
+          impl.echo(controller, request, done);
+        }
+        
+        @java.lang.Override
+        public  void error(
+            com.google.protobuf.RpcController controller,
+            org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto request,
+            com.google.protobuf.RpcCallback<org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto> done) {
+          impl.error(controller, request, done);
+        }
+        
+      };
+    }
+    
+    public static com.google.protobuf.BlockingService
+        newReflectiveBlockingService(final BlockingInterface impl) {
+      return new com.google.protobuf.BlockingService() {
+        public final com.google.protobuf.Descriptors.ServiceDescriptor
+            getDescriptorForType() {
+          return getDescriptor();
+        }
+        
+        public final com.google.protobuf.Message callBlockingMethod(
+            com.google.protobuf.Descriptors.MethodDescriptor method,
+            com.google.protobuf.RpcController controller,
+            com.google.protobuf.Message request)
+            throws com.google.protobuf.ServiceException {
+          if (method.getService() != getDescriptor()) {
+            throw new java.lang.IllegalArgumentException(
+              "Service.callBlockingMethod() given method descriptor for " +
+              "wrong service type.");
+          }
+          switch(method.getIndex()) {
+            case 0:
+              return impl.ping(controller, (org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto)request);
+            case 1:
+              return impl.echo(controller, (org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto)request);
+            case 2:
+              return impl.error(controller, (org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto)request);
+            default:
+              throw new java.lang.AssertionError("Can't get here.");
+          }
+        }
+        
+        public final com.google.protobuf.Message
+            getRequestPrototype(
+            com.google.protobuf.Descriptors.MethodDescriptor method) {
+          if (method.getService() != getDescriptor()) {
+            throw new java.lang.IllegalArgumentException(
+              "Service.getRequestPrototype() given method " +
+              "descriptor for wrong service type.");
+          }
+          switch(method.getIndex()) {
+            case 0:
+              return org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto.getDefaultInstance();
+            case 1:
+              return org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto.getDefaultInstance();
+            case 2:
+              return org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto.getDefaultInstance();
+            default:
+              throw new java.lang.AssertionError("Can't get here.");
+          }
+        }
+        
+        public final com.google.protobuf.Message
+            getResponsePrototype(
+            com.google.protobuf.Descriptors.MethodDescriptor method) {
+          if (method.getService() != getDescriptor()) {
+            throw new java.lang.IllegalArgumentException(
+              "Service.getResponsePrototype() given method " +
+              "descriptor for wrong service type.");
+          }
+          switch(method.getIndex()) {
+            case 0:
+              return org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto.getDefaultInstance();
+            case 1:
+              return org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto.getDefaultInstance();
+            case 2:
+              return org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto.getDefaultInstance();
+            default:
+              throw new java.lang.AssertionError("Can't get here.");
+          }
+        }
+        
+      };
+    }
+    
+    public abstract void ping(
+        com.google.protobuf.RpcController controller,
+        org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto request,
+        com.google.protobuf.RpcCallback<org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto> done);
+    
+    public abstract void echo(
+        com.google.protobuf.RpcController controller,
+        org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto request,
+        com.google.protobuf.RpcCallback<org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto> done);
+    
+    public abstract void error(
+        com.google.protobuf.RpcController controller,
+        org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto request,
+        com.google.protobuf.RpcCallback<org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto> done);
+    
+    public static final
+        com.google.protobuf.Descriptors.ServiceDescriptor
+        getDescriptor() {
+      return org.apache.hadoop.ipc.protobuf.TestRpcServiceProtos.getDescriptor().getServices().get(0);
+    }
+    public final com.google.protobuf.Descriptors.ServiceDescriptor
+        getDescriptorForType() {
+      return getDescriptor();
+    }
+    
+    public final void callMethod(
+        com.google.protobuf.Descriptors.MethodDescriptor method,
+        com.google.protobuf.RpcController controller,
+        com.google.protobuf.Message request,
+        com.google.protobuf.RpcCallback<
+          com.google.protobuf.Message> done) {
+      if (method.getService() != getDescriptor()) {
+        throw new java.lang.IllegalArgumentException(
+          "Service.callMethod() given method descriptor for wrong " +
+          "service type.");
+      }
+      switch(method.getIndex()) {
+        case 0:
+          this.ping(controller, (org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto)request,
+            com.google.protobuf.RpcUtil.<org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto>specializeCallback(
+              done));
+          return;
+        case 1:
+          this.echo(controller, (org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto)request,
+            com.google.protobuf.RpcUtil.<org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto>specializeCallback(
+              done));
+          return;
+        case 2:
+          this.error(controller, (org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto)request,
+            com.google.protobuf.RpcUtil.<org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto>specializeCallback(
+              done));
+          return;
+        default:
+          throw new java.lang.AssertionError("Can't get here.");
+      }
+    }
+    
+    public final com.google.protobuf.Message
+        getRequestPrototype(
+        com.google.protobuf.Descriptors.MethodDescriptor method) {
+      if (method.getService() != getDescriptor()) {
+        throw new java.lang.IllegalArgumentException(
+          "Service.getRequestPrototype() given method " +
+          "descriptor for wrong service type.");
+      }
+      switch(method.getIndex()) {
+        case 0:
+          return org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto.getDefaultInstance();
+        case 1:
+          return org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto.getDefaultInstance();
+        case 2:
+          return org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto.getDefaultInstance();
+        default:
+          throw new java.lang.AssertionError("Can't get here.");
+      }
+    }
+    
+    public final com.google.protobuf.Message
+        getResponsePrototype(
+        com.google.protobuf.Descriptors.MethodDescriptor method) {
+      if (method.getService() != getDescriptor()) {
+        throw new java.lang.IllegalArgumentException(
+          "Service.getResponsePrototype() given method " +
+          "descriptor for wrong service type.");
+      }
+      switch(method.getIndex()) {
+        case 0:
+          return org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto.getDefaultInstance();
+        case 1:
+          return org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto.getDefaultInstance();
+        case 2:
+          return org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto.getDefaultInstance();
+        default:
+          throw new java.lang.AssertionError("Can't get here.");
+      }
+    }
+    
+    public static Stub newStub(
+        com.google.protobuf.RpcChannel channel) {
+      return new Stub(channel);
+    }
+    
+    public static final class Stub extends org.apache.hadoop.ipc.protobuf.TestRpcServiceProtos.TestProtobufRpcProto implements Interface {
+      private Stub(com.google.protobuf.RpcChannel channel) {
+        this.channel = channel;
+      }
+      
+      private final com.google.protobuf.RpcChannel channel;
+      
+      public com.google.protobuf.RpcChannel getChannel() {
+        return channel;
+      }
+      
+      public  void ping(
+          com.google.protobuf.RpcController controller,
+          org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto request,
+          com.google.protobuf.RpcCallback<org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto> done) {
+        channel.callMethod(
+          getDescriptor().getMethods().get(0),
+          controller,
+          request,
+          org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto.getDefaultInstance(),
+          com.google.protobuf.RpcUtil.generalizeCallback(
+            done,
+            org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto.class,
+            org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto.getDefaultInstance()));
+      }
+      
+      public  void echo(
+          com.google.protobuf.RpcController controller,
+          org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto request,
+          com.google.protobuf.RpcCallback<org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto> done) {
+        channel.callMethod(
+          getDescriptor().getMethods().get(1),
+          controller,
+          request,
+          org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto.getDefaultInstance(),
+          com.google.protobuf.RpcUtil.generalizeCallback(
+            done,
+            org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto.class,
+            org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto.getDefaultInstance()));
+      }
+      
+      public  void error(
+          com.google.protobuf.RpcController controller,
+          org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto request,
+          com.google.protobuf.RpcCallback<org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto> done) {
+        channel.callMethod(
+          getDescriptor().getMethods().get(2),
+          controller,
+          request,
+          org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto.getDefaultInstance(),
+          com.google.protobuf.RpcUtil.generalizeCallback(
+            done,
+            org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto.class,
+            org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto.getDefaultInstance()));
+      }
+    }
+    
+    public static BlockingInterface newBlockingStub(
+        com.google.protobuf.BlockingRpcChannel channel) {
+      return new BlockingStub(channel);
+    }
+    
+    public interface BlockingInterface {
+      public org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto ping(
+          com.google.protobuf.RpcController controller,
+          org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto request)
+          throws com.google.protobuf.ServiceException;
+      
+      public org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto echo(
+          com.google.protobuf.RpcController controller,
+          org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto request)
+          throws com.google.protobuf.ServiceException;
+      
+      public org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto error(
+          com.google.protobuf.RpcController controller,
+          org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto request)
+          throws com.google.protobuf.ServiceException;
+    }
+    
+    private static final class BlockingStub implements BlockingInterface {
+      private BlockingStub(com.google.protobuf.BlockingRpcChannel channel) {
+        this.channel = channel;
+      }
+      
+      private final com.google.protobuf.BlockingRpcChannel channel;
+      
+      public org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto ping(
+          com.google.protobuf.RpcController controller,
+          org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto request)
+          throws com.google.protobuf.ServiceException {
+        return (org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto) channel.callBlockingMethod(
+          getDescriptor().getMethods().get(0),
+          controller,
+          request,
+          org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto.getDefaultInstance());
+      }
+      
+      
+      public org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto echo(
+          com.google.protobuf.RpcController controller,
+          org.apache.hadoop.ipc.protobuf.TestProtos.EchoRequestProto request)
+          throws com.google.protobuf.ServiceException {
+        return (org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto) channel.callBlockingMethod(
+          getDescriptor().getMethods().get(1),
+          controller,
+          request,
+          org.apache.hadoop.ipc.protobuf.TestProtos.EchoResponseProto.getDefaultInstance());
+      }
+      
+      
+      public org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto error(
+          com.google.protobuf.RpcController controller,
+          org.apache.hadoop.ipc.protobuf.TestProtos.EmptyRequestProto request)
+          throws com.google.protobuf.ServiceException {
+        return (org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto) channel.callBlockingMethod(
+          getDescriptor().getMethods().get(2),
+          controller,
+          request,
+          org.apache.hadoop.ipc.protobuf.TestProtos.EmptyResponseProto.getDefaultInstance());
+      }
+      
+    }
+  }
+  
+  
+  public static com.google.protobuf.Descriptors.FileDescriptor
+      getDescriptor() {
+    return descriptor;
+  }
+  private static com.google.protobuf.Descriptors.FileDescriptor
+      descriptor;
+  static {
+    java.lang.String[] descriptorData = {
+      "\n\026test_rpc_service.proto\032\ntest.proto2\250\001\n" +
+      "\024TestProtobufRpcProto\022/\n\004ping\022\022.EmptyReq" +
+      "uestProto\032\023.EmptyResponseProto\022-\n\004echo\022\021" +
+      ".EchoRequestProto\032\022.EchoResponseProto\0220\n" +
+      "\005error\022\022.EmptyRequestProto\032\023.EmptyRespon" +
+      "seProtoB<\n\036org.apache.hadoop.ipc.protobu" +
+      "fB\024TestRpcServiceProtos\210\001\001\240\001\001"
+    };
+    com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner assigner =
+      new com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner() {
+        public com.google.protobuf.ExtensionRegistry assignDescriptors(
+            com.google.protobuf.Descriptors.FileDescriptor root) {
+          descriptor = root;
+          return null;
+        }
+      };
+    com.google.protobuf.Descriptors.FileDescriptor
+      .internalBuildGeneratedFileFrom(descriptorData,
+        new com.google.protobuf.Descriptors.FileDescriptor[] {
+          org.apache.hadoop.ipc.protobuf.TestProtos.getDescriptor(),
+        }, assigner);
+  }
+  
+  // @@protoc_insertion_point(outer_class_scope)
+}

hadoop-common-project/hadoop-common/src/test/proto/test.proto

@@ -0,0 +1,35 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+option java_package = "org.apache.hadoop.ipc.protobuf";
+option java_outer_classname = "TestProtos";
+option java_generate_equals_and_hash = true;
+
+message EmptyRequestProto {
+}
+
+message EmptyResponseProto {
+}
+
+message EchoRequestProto {
+  required string message = 1;
+}
+
+message EchoResponseProto {
+  required string message = 1;
+}

hadoop-common-project/hadoop-common/src/test/proto/test_rpc_service.proto

@@ -0,0 +1,33 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+option java_package = "org.apache.hadoop.ipc.protobuf";
+option java_outer_classname = "TestRpcServiceProtos";
+option java_generic_services = true;
+option java_generate_equals_and_hash = true;
+
+import "test.proto";
+
+
+/**
+ * A protobuf service for use in tests
+ */
+service TestProtobufRpcProto {
+  rpc ping(EmptyRequestProto) returns (EmptyResponseProto);
+  rpc echo(EchoRequestProto) returns (EchoResponseProto);
+  rpc error(EmptyRequestProto) returns (EmptyResponseProto);
+}