svn merge -c 1210657 from trunk for HDFS-2581.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23-PB@1230386 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -5,7 +5,7 @@ Release 0.23-PB - Unreleased
   NEW FEATURES
 
     HDFS-395.  DFS Scalability: Incremental block reports. (Tomasz Nykiel
-               via hairong)
+    via hairong)
 
     HDFS-2517. Add protobuf service for JounralProtocol. (suresh)
 
@@ -15,6 +15,8 @@ Release 0.23-PB - Unreleased
 
     HDFS-2519. Add protobuf service for DatanodeProtocol. (suresh)
 
+    HDFS-2581. Implement protobuf service for JournalProtocol. (suresh)
+
   IMPROVEMENTS
 
     HDFS-2018. Move all journal stream management code into one place.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/JournalProtocolPB.java

@@ -0,0 +1,53 @@
+/**
+ * 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.hdfs.protocolPB;
+
+import java.io.IOException;
+
+import org.apache.hadoop.hdfs.protocol.proto.JournalProtocolProtos.JournalProtocolService;
+import org.apache.hadoop.hdfs.protocolR23Compatible.ProtocolSignatureWritable;
+import org.apache.hadoop.security.KerberosInfo;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.ipc.ProtocolInfo;
+import org.apache.hadoop.ipc.VersionedProtocol;
+
+/**
+ * Protocol used to journal edits to a remote node. Currently,
+ * this is used to publish edits from the NameNode to a BackupNode.
+ * 
+ * Note: This extends the protocolbuffer service based interface to
+ * add annotations required for security.
+ */
+@KerberosInfo(
+    serverPrincipal = DFSConfigKeys.DFS_NAMENODE_USER_NAME_KEY,
+    clientPrincipal = DFSConfigKeys.DFS_NAMENODE_USER_NAME_KEY)
+@ProtocolInfo(protocolName = 
+    "org.apache.hadoop.hdfs.server.protocol.JournalProtocol",
+    protocolVersion = 1)
+@InterfaceAudience.Private
+public interface JournalProtocolPB extends
+    JournalProtocolService.BlockingInterface, VersionedProtocol {
+  /**
+   * This method is defined to get the protocol signature using 
+   * the R23 protocol - hence we have added the suffix of 2 the method name
+   * to avoid conflict.
+   */
+  public ProtocolSignatureWritable getProtocolSignature2(String protocol,
+      long clientVersion, int clientMethodsHash) throws IOException;
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/JournalProtocolServerSideTranslatorPB.java

@@ -0,0 +1,121 @@
+/**
+ * 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.hdfs.protocolPB;
+
+import java.io.IOException;
+
+import org.apache.hadoop.hdfs.protocol.proto.JournalProtocolProtos.JournalRequestProto;
+import org.apache.hadoop.hdfs.protocol.proto.JournalProtocolProtos.JournalResponseProto;
+import org.apache.hadoop.hdfs.protocol.proto.JournalProtocolProtos.StartLogSegmentRequestProto;
+import org.apache.hadoop.hdfs.protocol.proto.JournalProtocolProtos.StartLogSegmentResponseProto;
+import org.apache.hadoop.hdfs.protocolR23Compatible.ProtocolSignatureWritable;
+import org.apache.hadoop.hdfs.server.protocol.JournalProtocol;
+import org.apache.hadoop.ipc.ProtocolSignature;
+import org.apache.hadoop.ipc.RPC;
+import org.apache.hadoop.ipc.VersionedProtocol;
+
+import com.google.protobuf.RpcController;
+import com.google.protobuf.ServiceException;
+
+/**
+ * Implementation for protobuf service that forwards requests
+ * received on {@link JournalProtocolPB} to the 
+ * {@link JournalProtocol} server implementation.
+ */
+public class JournalProtocolServerSideTranslatorPB implements JournalProtocolPB {
+  /** Server side implementation to delegate the requests to */
+  private final JournalProtocol impl;
+
+  public JournalProtocolServerSideTranslatorPB(JournalProtocol impl) {
+    this.impl = impl;
+  }
+
+  /** @see JournalProtocol#journal */
+  @Override
+  public JournalResponseProto journal(RpcController unused,
+      JournalRequestProto req) throws ServiceException {
+    try {
+      impl.journal(PBHelper.convert(req.getRegistration()),
+          req.getFirstTxnId(), req.getNumTxns(), req.getRecords()
+              .toByteArray());
+    } catch (IOException e) {
+      throw new ServiceException(e);
+    }
+    return JournalResponseProto.newBuilder().build();
+  }
+
+  /** @see JournalProtocol#startLogSegment */
+  @Override
+  public StartLogSegmentResponseProto startLogSegment(RpcController controller,
+      StartLogSegmentRequestProto req) throws ServiceException {
+    try {
+      impl.startLogSegment(PBHelper.convert(req.getRegistration()),
+          req.getTxid());
+    } catch (IOException e) {
+      throw new ServiceException(e);
+    }
+    return StartLogSegmentResponseProto.newBuilder().build();
+  }
+
+  /** @see VersionedProtocol#getProtocolVersion */
+  @Override
+  public long getProtocolVersion(String protocol, long clientVersion)
+      throws IOException {
+    return RPC.getProtocolVersion(JournalProtocolPB.class);
+  }
+
+  /**
+   * The client side will redirect getProtocolSignature to
+   * getProtocolSignature2.
+   * 
+   * However the RPC layer below on the Server side will call getProtocolVersion
+   * and possibly in the future getProtocolSignature. Hence we still implement
+   * it even though the end client will never call this method.
+   * 
+   * @see VersionedProtocol#getProtocolSignature(String, long, int)
+   */
+  @Override
+  public ProtocolSignature getProtocolSignature(String protocol,
+      long clientVersion, int clientMethodsHash) throws IOException {
+    /**
+     * Don't forward this to the server. The protocol version and signature is
+     * that of {@link JournalProtocol}
+     */
+    if (!protocol.equals(RPC.getProtocolName(JournalProtocolPB.class))) {
+      throw new IOException("Namenode Serverside implements " +
+          RPC.getProtocolName(JournalProtocolPB.class) +
+          ". The following requested protocol is unknown: " + protocol);
+    }
+
+    return ProtocolSignature.getProtocolSignature(clientMethodsHash,
+        RPC.getProtocolVersion(JournalProtocolPB.class),
+        JournalProtocolPB.class);
+  }
+
+
+  @Override
+  public ProtocolSignatureWritable getProtocolSignature2(String protocol,
+      long clientVersion, int clientMethodsHash) throws IOException {
+    /**
+     * Don't forward this to the server. The protocol version and signature is
+     * that of {@link JournalPBProtocol}
+     */
+    return ProtocolSignatureWritable.convert(
+        this.getProtocolSignature(protocol, clientVersion, clientMethodsHash));
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/JournalProtocolTranslatorPB.java

@@ -0,0 +1,106 @@
+/**
+ * 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.hdfs.protocolPB;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.net.InetSocketAddress;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdfs.protocol.proto.JournalProtocolProtos.JournalRequestProto;
+import org.apache.hadoop.hdfs.protocol.proto.JournalProtocolProtos.StartLogSegmentRequestProto;
+import org.apache.hadoop.hdfs.protocolR23Compatible.ProtocolSignatureWritable;
+import org.apache.hadoop.hdfs.server.protocol.JournalProtocol;
+import org.apache.hadoop.hdfs.server.protocol.NamenodeRegistration;
+import org.apache.hadoop.ipc.ProtobufRpcEngine;
+import org.apache.hadoop.ipc.ProtobufHelper;
+import org.apache.hadoop.ipc.ProtocolSignature;
+import org.apache.hadoop.ipc.RPC;
+
+import com.google.protobuf.RpcController;
+import com.google.protobuf.ServiceException;
+
+/**
+ * This class is the client side translator to translate the requests made on
+ * {@link JournalProtocol} interfaces to the RPC server implementing
+ * {@link JournalProtocolPB}.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Stable
+public class JournalProtocolTranslatorPB implements JournalProtocol, Closeable {
+  /** RpcController is not used and hence is set to null */
+  private final static RpcController NULL_CONTROLLER = null;
+  private final JournalProtocolPB rpcProxy;
+
+  public JournalProtocolTranslatorPB(InetSocketAddress nameNodeAddr,
+      Configuration conf) throws IOException {
+    RPC.setProtocolEngine(conf, JournalProtocolPB.class, ProtobufRpcEngine.class);
+    rpcProxy = RPC.getProxy(JournalProtocolPB.class,
+        JournalProtocol.versionID, nameNodeAddr, conf);
+  }
+
+  @Override
+  public void close() {
+    RPC.stopProxy(rpcProxy);
+  }
+
+  @Override
+  public long getProtocolVersion(String protocolName, long clientVersion)
+      throws IOException {
+    return 0;
+  }
+
+  @Override
+  public ProtocolSignature getProtocolSignature(String protocol,
+      long clientVersion, int clientMethodsHash) throws IOException {
+    return ProtocolSignatureWritable.convert(rpcProxy.getProtocolSignature2(
+        protocol, clientVersion, clientMethodsHash));
+  }
+
+  @Override
+  public void journal(NamenodeRegistration reg, long firstTxnId,
+      int numTxns, byte[] records) throws IOException {
+    JournalRequestProto req = JournalRequestProto.newBuilder()
+        .setRegistration(PBHelper.convert(reg))
+        .setFirstTxnId(firstTxnId)
+        .setNumTxns(numTxns)
+        .setRecords(PBHelper.getByteString(records))
+        .build();
+    try {
+      rpcProxy.journal(NULL_CONTROLLER, req);
+    } catch (ServiceException e) {
+      throw ProtobufHelper.getRemoteException(e);
+    }
+  }
+
+  @Override
+  public void startLogSegment(NamenodeRegistration registration, long txid)
+      throws IOException {
+    StartLogSegmentRequestProto req = StartLogSegmentRequestProto.newBuilder()
+        .setRegistration(PBHelper.convert(registration))
+        .setTxid(txid)
+        .build();
+    try {
+      rpcProxy.startLogSegment(NULL_CONTROLLER, req);
+    } catch (ServiceException e) {
+      throw ProtobufHelper.getRemoteException(e);
+    }
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelper.java

@@ -0,0 +1,92 @@
+/**
+ * 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.hdfs.protocolPB;
+
+import org.apache.hadoop.hdfs.protocol.proto.HdfsProtos.NamenodeRegistrationProto;
+import org.apache.hadoop.hdfs.protocol.proto.HdfsProtos.NamenodeRegistrationProto.NamenodeRoleProto;
+import org.apache.hadoop.hdfs.protocol.proto.HdfsProtos.StorageInfoProto;
+import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.NamenodeRole;
+import org.apache.hadoop.hdfs.server.common.StorageInfo;
+import org.apache.hadoop.hdfs.server.protocol.NamenodeRegistration;
+
+import com.google.protobuf.ByteString;
+
+/**
+ * Utilities for converting protobuf classes to and from 
+ * implementation classes.
+ */
+class PBHelper {
+  private PBHelper() {
+    /** Hidden constructor */
+  }
+  
+  public static ByteString getByteString(byte[] bytes) {
+    return ByteString.copyFrom(bytes);
+  }
+  
+  public static NamenodeRole convert(NamenodeRoleProto role) {
+    switch (role) {
+    case NAMENODE:
+      return NamenodeRole.NAMENODE;
+    case BACKUP:
+      return NamenodeRole.BACKUP;
+    case CHECKPOINT:
+      return NamenodeRole.CHECKPOINT;
+    }
+    return null;
+  }
+  
+  public static NamenodeRoleProto convert(NamenodeRole role) {
+    switch (role) {
+    case NAMENODE:
+      return NamenodeRoleProto.NAMENODE;
+    case BACKUP:
+      return NamenodeRoleProto.BACKUP;
+    case CHECKPOINT:
+      return NamenodeRoleProto.CHECKPOINT;
+    }
+    return null;
+  }
+  
+  public static StorageInfoProto convert(StorageInfo info) {
+    return StorageInfoProto.newBuilder().setClusterID(info.getClusterID())
+        .setCTime(info.getCTime())
+        .setLayoutVersion(info.getLayoutVersion())
+        .setNamespceID(info.getNamespaceID())
+        .build();
+  }
+  
+  public static StorageInfo convert(StorageInfoProto info) {
+    return new StorageInfo(info.getLayoutVersion(), info.getNamespceID(),
+        info.getClusterID(), info.getCTime());
+  }
+  
+  
+  public static NamenodeRegistrationProto convert(NamenodeRegistration reg) {
+    return NamenodeRegistrationProto.newBuilder()
+        .setHttpAddress(reg.getHttpAddress())
+        .setRole(convert(reg.getRole()))
+        .setRpcAddress(reg.getAddress())
+        .setStorageInfo(convert((StorageInfo) reg)).build();
+  }
+  
+  public static NamenodeRegistration convert(NamenodeRegistrationProto reg) {
+    return new NamenodeRegistration(reg.getRpcAddress(), reg.getHttpAddress(),
+        convert(reg.getStorageInfo()), convert(reg.getRole()));
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/overview.html

@@ -0,0 +1,62 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
+<html>
+<!--
+   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.
+-->
+<head>
+   <title>Protocol Buffers based data types for NN protocols</title>
+</head>
+<body>
+<p>
+The Protocol Buffers data types for NN protocols that use PB go in this package.
+</p>
+<h1>Steps to add a new protocol</h1>
+<hr/>
+<ol>
+<li>Define the protobuf service for the protocol in &lt;ProtocolName&gt;.proto class. 
+<ul>
+<li>This file should include both the protobuf service definition and the types
+ used for request and response. For example see - NamenodeProtocol.proto
+<li>The naming convention for the protobuf service is &lt;ProtocolName&gt;Service.
+Example: NamenodeProtocolService.
+<li>Every RPC method takes a request and returns a response. The request 
+naming convention is &lt;MethodName&gt;RequestProto. The response naming convention 
+is &lt;MethodName&gt;ResponseProto.
+</ul>
+<li>Generate java files from the proto file using protoc tool.
+<li>Define server side interface that extends BlockingInterface from the 
+generated files (Example: NamenodeProtocolService.BlockingInterface) 
+and VersionedProtocol. See NamenodePBProtocol.java for example.
+<li>Define client side translator to translate the client protocol to 
+protobuf. See NamenodeProtocolTranslator.
+<li>Define server side implementation that implements the server side interface.
+This implementation receives the protobuf requests and delegates it to the 
+server side implementation. See NamenodePBProtocolImpl for example.
+<li>Make changes to register this protocol at the server. See the other 
+protocols on how this is done.
+</ol>
+<h1>Steps to make changes to the existing protocol in a compatible way</h1>
+<hr/>
+<ol>
+<li>Adding new methods is a compatible change.</li>
+<li>When modifying an existing method, do not change the required parameters 
+to optional or optional parameters to required. Only add optional parameters 
+to the request and response.</li>
+<li>When modifying an existing type, do not change the required parameters 
+to optional or optional parameters to require and optional parameters to 
+required. Only add optional parameters to the request and response.</li>
+</ol>
+

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolProtocolBuffers/overview.html

@@ -1,29 +0,0 @@
-<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
-<html>
-<!--
-   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.
--->
-<head>
-   <title>Protocol Buffers based data types for NN protocols</title>
-</head>
-<body>
-<p>
-The Protocol Buffers data types for NN protocols that use 
-PB go in this package.
-</p>
-
-
-

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/protocolPB/TestPBHelper.java

@@ -0,0 +1,79 @@
+/**
+ * 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.hdfs.protocolPB;
+
+import static junit.framework.Assert.*;
+
+import org.apache.hadoop.hdfs.protocol.proto.HdfsProtos.NamenodeRegistrationProto;
+import org.apache.hadoop.hdfs.protocol.proto.HdfsProtos.NamenodeRegistrationProto.NamenodeRoleProto;
+import org.apache.hadoop.hdfs.protocol.proto.HdfsProtos.StorageInfoProto;
+import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.NamenodeRole;
+import org.apache.hadoop.hdfs.server.common.StorageInfo;
+import org.apache.hadoop.hdfs.server.protocol.NamenodeRegistration;
+import org.junit.Test;
+
+/**
+ * Tests for {@link PBHelper}
+ */
+public class TestPBHelper {
+  @Test
+  public void testConvertNamenodeRole() {
+    assertEquals(NamenodeRoleProto.BACKUP,
+        PBHelper.convert(NamenodeRole.BACKUP));
+    assertEquals(NamenodeRoleProto.CHECKPOINT,
+        PBHelper.convert(NamenodeRole.CHECKPOINT));
+    assertEquals(NamenodeRoleProto.NAMENODE,
+        PBHelper.convert(NamenodeRole.NAMENODE));
+    assertEquals(NamenodeRole.BACKUP,
+        PBHelper.convert(NamenodeRoleProto.BACKUP));
+    assertEquals(NamenodeRole.CHECKPOINT,
+        PBHelper.convert(NamenodeRoleProto.CHECKPOINT));
+    assertEquals(NamenodeRole.NAMENODE,
+        PBHelper.convert(NamenodeRoleProto.NAMENODE));
+  }
+  
+  @Test
+  public void testConvertStoragInfo() {
+    StorageInfo info = new StorageInfo(1, 2, "cid", 3);
+    StorageInfoProto infoProto = PBHelper.convert(info);
+    StorageInfo info2 = PBHelper.convert(infoProto);
+    assertEquals(info.getClusterID(), info2.getClusterID());
+    assertEquals(info.getCTime(), info2.getCTime());
+    assertEquals(info.getLayoutVersion(), info2.getLayoutVersion());
+    assertEquals(info.getNamespaceID(), info2.getNamespaceID());
+  }
+  
+  @Test
+  public void testConvertNamenodeRegistration() {
+    StorageInfo info = new StorageInfo(1, 2, "cid", 3);
+    NamenodeRegistration reg = new NamenodeRegistration("address:999",
+        "http:1000", info, NamenodeRole.NAMENODE);
+    NamenodeRegistrationProto regProto = PBHelper.convert(reg);
+    NamenodeRegistration reg2 = PBHelper.convert(regProto);
+    assertEquals(reg.getAddress(), reg2.getAddress());
+    assertEquals(reg.getClusterID(), reg2.getClusterID());
+    assertEquals(reg.getCTime(), reg2.getCTime());
+    assertEquals(reg.getHttpAddress(), reg2.getHttpAddress());
+    assertEquals(reg.getLayoutVersion(), reg2.getLayoutVersion());
+    assertEquals(reg.getNamespaceID(), reg2.getNamespaceID());
+    assertEquals(reg.getRegistrationID(), reg2.getRegistrationID());
+    assertEquals(reg.getRole(), reg2.getRole());
+    assertEquals(reg.getVersion(), reg2.getVersion());
+    
+  }
+}