HBASE-12597

Signed-off-by: stack <stack@apache.org>

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionManager.java

@@ -67,6 +67,7 @@ import org.apache.hadoop.hbase.client.MetaScanner.MetaScannerVisitorBase;
 import org.apache.hadoop.hbase.client.coprocessor.Batch;
 import org.apache.hadoop.hbase.exceptions.RegionMovedException;
 import org.apache.hadoop.hbase.exceptions.RegionOpeningException;
+import org.apache.hadoop.hbase.ipc.RpcClientFactory;
 import org.apache.hadoop.hbase.ipc.RpcClient;
 import org.apache.hadoop.hbase.ipc.RpcControllerFactory;
 import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
@@ -619,7 +620,7 @@ class ConnectionManager {
       this.registry = setupRegistry();
       retrieveClusterId();
 
-      this.rpcClient = new RpcClient(this.conf, this.clusterId);
+      this.rpcClient = RpcClientFactory.createClient(this.conf, this.clusterId);
       this.rpcControllerFactory = RpcControllerFactory.instantiate(conf);
 
       // Do we publish the status?
@@ -639,7 +640,7 @@ class ConnectionManager {
                 @Override
                 public void newDead(ServerName sn) {
                   clearCaches(sn);
-                  rpcClient.cancelConnections(sn.getHostname(), sn.getPort());
+                  rpcClient.cancelConnections(sn);
                 }
               }, conf, listenerClass);
         }
@@ -783,18 +784,6 @@ class ConnectionManager {
       return RegistryFactory.getRegistry(this);
     }
 
-    /**
-     * For tests only.
-     * @param rpcClient Client we should use instead.
-     * @return Previous rpcClient
-     */
-    @VisibleForTesting
-    RpcClient setRpcClient(final RpcClient rpcClient) {
-      RpcClient oldRpcClient = this.rpcClient;
-      this.rpcClient = rpcClient;
-      return oldRpcClient;
-    }
-
     /**
      * For tests only.
      */
@@ -2336,7 +2325,7 @@ class ConnectionManager {
         clusterStatusListener.close();
       }
       if (rpcClient != null) {
-        rpcClient.stop();
+        rpcClient.close();
       }
     }
 

hbase-client/src/main/java/org/apache/hadoop/hbase/client/PreemptiveFastFailInterceptor.java

@@ -39,7 +39,7 @@ import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.exceptions.ConnectionClosingException;
 import org.apache.hadoop.hbase.exceptions.PreemptiveFastFailException;
-import org.apache.hadoop.hbase.ipc.RpcClient.FailedServerException;
+import org.apache.hadoop.hbase.ipc.FailedServerException;
 import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
 import org.apache.hadoop.ipc.RemoteException;
 

hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/AbstractRpcClient.java

@@ -0,0 +1,177 @@
+/**
+ * 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.hbase.ipc;
+
+import com.google.common.annotations.VisibleForTesting;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.classification.InterfaceAudience;
+import org.apache.hadoop.hbase.codec.Codec;
+import org.apache.hadoop.hbase.codec.KeyValueCodec;
+import org.apache.hadoop.hbase.security.UserProvider;
+import org.apache.hadoop.hbase.util.PoolMap;
+import org.apache.hadoop.io.compress.CompressionCodec;
+
+import java.net.SocketAddress;
+
+/**
+ * Provides the basics for a RpcClient implementation like configuration and Logging.
+ */
+@InterfaceAudience.Private
+public abstract class AbstractRpcClient implements RpcClient {
+  public static final Log LOG = LogFactory.getLog(AbstractRpcClient.class);
+
+  protected final Configuration conf;
+  protected String clusterId;
+  protected final SocketAddress localAddr;
+
+  protected UserProvider userProvider;
+  protected final IPCUtil ipcUtil;
+
+  protected final int minIdleTimeBeforeClose; // if the connection is idle for more than this
+  // time (in ms), it will be closed at any moment.
+  protected final int maxRetries; //the max. no. of retries for socket connections
+  protected final long failureSleep; // Time to sleep before retry on failure.
+  protected final boolean tcpNoDelay; // if T then disable Nagle's Algorithm
+  protected final boolean tcpKeepAlive; // if T then use keepalives
+  protected final Codec codec;
+  protected final CompressionCodec compressor;
+  protected final boolean fallbackAllowed;
+
+  protected final int connectTO;
+  protected final int readTO;
+  protected final int writeTO;
+
+  /**
+   * Construct an IPC client for the cluster <code>clusterId</code>
+   *
+   * @param conf configuration
+   * @param clusterId the cluster id
+   * @param localAddr client socket bind address.
+   */
+  public AbstractRpcClient(Configuration conf, String clusterId, SocketAddress localAddr) {
+    this.userProvider = UserProvider.instantiate(conf);
+    this.localAddr = localAddr;
+    this.tcpKeepAlive = conf.getBoolean("hbase.ipc.client.tcpkeepalive", true);
+    this.clusterId = clusterId != null ? clusterId : HConstants.CLUSTER_ID_DEFAULT;
+    this.failureSleep = conf.getLong(HConstants.HBASE_CLIENT_PAUSE,
+        HConstants.DEFAULT_HBASE_CLIENT_PAUSE);
+    this.maxRetries = conf.getInt("hbase.ipc.client.connect.max.retries", 0);
+    this.tcpNoDelay = conf.getBoolean("hbase.ipc.client.tcpnodelay", true);
+    this.ipcUtil = new IPCUtil(conf);
+
+    this.minIdleTimeBeforeClose = conf.getInt(IDLE_TIME, 120000); // 2 minutes
+    this.conf = conf;
+    this.codec = getCodec();
+    this.compressor = getCompressor(conf);
+    this.fallbackAllowed = conf.getBoolean(IPC_CLIENT_FALLBACK_TO_SIMPLE_AUTH_ALLOWED_KEY,
+        IPC_CLIENT_FALLBACK_TO_SIMPLE_AUTH_ALLOWED_DEFAULT);
+    this.connectTO = conf.getInt(SOCKET_TIMEOUT_CONNECT, DEFAULT_SOCKET_TIMEOUT_CONNECT);
+    this.readTO = conf.getInt(SOCKET_TIMEOUT_READ, DEFAULT_SOCKET_TIMEOUT_READ);
+    this.writeTO = conf.getInt(SOCKET_TIMEOUT_WRITE, DEFAULT_SOCKET_TIMEOUT_WRITE);
+
+    // login the server principal (if using secure Hadoop)
+    if (LOG.isDebugEnabled()) {
+      LOG.debug("Codec=" + this.codec + ", compressor=" + this.compressor +
+          ", tcpKeepAlive=" + this.tcpKeepAlive +
+          ", tcpNoDelay=" + this.tcpNoDelay +
+          ", connectTO=" + this.connectTO +
+          ", readTO=" + this.readTO +
+          ", writeTO=" + this.writeTO +
+          ", minIdleTimeBeforeClose=" + this.minIdleTimeBeforeClose +
+          ", maxRetries=" + this.maxRetries +
+          ", fallbackAllowed=" + this.fallbackAllowed +
+          ", bind address=" + (this.localAddr != null ? this.localAddr : "null"));
+    }
+  }
+
+  @VisibleForTesting
+  public static String getDefaultCodec(final Configuration c) {
+    // If "hbase.client.default.rpc.codec" is empty string -- you can't set it to null because
+    // Configuration will complain -- then no default codec (and we'll pb everything).  Else
+    // default is KeyValueCodec
+    return c.get(DEFAULT_CODEC_CLASS, KeyValueCodec.class.getCanonicalName());
+  }
+
+  /**
+   * Encapsulate the ugly casting and RuntimeException conversion in private method.
+   * @return Codec to use on this client.
+   */
+  Codec getCodec() {
+    // For NO CODEC, "hbase.client.rpc.codec" must be configured with empty string AND
+    // "hbase.client.default.rpc.codec" also -- because default is to do cell block encoding.
+    String className = conf.get(HConstants.RPC_CODEC_CONF_KEY, getDefaultCodec(this.conf));
+    if (className == null || className.length() == 0) return null;
+    try {
+      return (Codec)Class.forName(className).newInstance();
+    } catch (Exception e) {
+      throw new RuntimeException("Failed getting codec " + className, e);
+    }
+  }
+
+  /**
+   * Encapsulate the ugly casting and RuntimeException conversion in private method.
+   * @param conf configuration
+   * @return The compressor to use on this client.
+   */
+  private static CompressionCodec getCompressor(final Configuration conf) {
+    String className = conf.get("hbase.client.rpc.compressor", null);
+    if (className == null || className.isEmpty()) return null;
+    try {
+        return (CompressionCodec)Class.forName(className).newInstance();
+    } catch (Exception e) {
+      throw new RuntimeException("Failed getting compressor " + className, e);
+    }
+  }
+
+  /**
+   * Return the pool type specified in the configuration, which must be set to
+   * either {@link org.apache.hadoop.hbase.util.PoolMap.PoolType#RoundRobin} or
+   * {@link org.apache.hadoop.hbase.util.PoolMap.PoolType#ThreadLocal},
+   * otherwise default to the former.
+   *
+   * For applications with many user threads, use a small round-robin pool. For
+   * applications with few user threads, you may want to try using a
+   * thread-local pool. In any case, the number of {@link org.apache.hadoop.hbase.ipc.RpcClient}
+   * instances should not exceed the operating system's hard limit on the number of
+   * connections.
+   *
+   * @param config configuration
+   * @return either a {@link org.apache.hadoop.hbase.util.PoolMap.PoolType#RoundRobin} or
+   *         {@link org.apache.hadoop.hbase.util.PoolMap.PoolType#ThreadLocal}
+   */
+  protected static PoolMap.PoolType getPoolType(Configuration config) {
+    return PoolMap.PoolType
+        .valueOf(config.get(HConstants.HBASE_CLIENT_IPC_POOL_TYPE), PoolMap.PoolType.RoundRobin,
+            PoolMap.PoolType.ThreadLocal);
+  }
+
+  /**
+   * Return the pool size specified in the configuration, which is applicable only if
+   * the pool type is {@link org.apache.hadoop.hbase.util.PoolMap.PoolType#RoundRobin}.
+   *
+   * @param config configuration
+   * @return the maximum pool size
+   */
+  protected static int getPoolSize(Configuration config) {
+    return config.getInt(HConstants.HBASE_CLIENT_IPC_POOL_SIZE, 1);
+  }
+}

hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/Call.java

@@ -0,0 +1,127 @@
+/**
+ * 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.hbase.ipc;
+
+import com.google.protobuf.Descriptors;
+import com.google.protobuf.Message;
+import org.apache.hadoop.hbase.CellScanner;
+import org.apache.hadoop.hbase.classification.InterfaceAudience;
+import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
+import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
+
+import java.io.IOException;
+
+/** A call waiting for a value. */
+@InterfaceAudience.Private
+public class Call {
+  final int id;                                 // call id
+  final Message param;                          // rpc request method param object
+  /**
+   * Optionally has cells when making call.  Optionally has cells set on response.  Used
+   * passing cells to the rpc and receiving the response.
+   */
+  CellScanner cells;
+  Message response;                             // value, null if error
+  // The return type.  Used to create shell into which we deserialize the response if any.
+  Message responseDefaultType;
+  IOException error;                            // exception, null if value
+  volatile boolean done;                                 // true when call is done
+  long startTime;
+  final Descriptors.MethodDescriptor md;
+  final int timeout; // timeout in millisecond for this call; 0 means infinite.
+
+  protected Call(int id, final Descriptors.MethodDescriptor md, Message param,
+      final CellScanner cells, final Message responseDefaultType, int timeout) {
+    this.param = param;
+    this.md = md;
+    this.cells = cells;
+    this.startTime = EnvironmentEdgeManager.currentTime();
+    this.responseDefaultType = responseDefaultType;
+    this.id = id;
+    this.timeout = timeout;
+  }
+
+  /**
+   * Check if the call did timeout. Set an exception (includes a notify) if it's the case.
+   * @return true if the call is on timeout, false otherwise.
+   */
+  public boolean checkAndSetTimeout() {
+    if (timeout == 0){
+      return false;
+    }
+
+    long waitTime = EnvironmentEdgeManager.currentTime() - getStartTime();
+    if (waitTime >= timeout) {
+      IOException ie = new CallTimeoutException("Call id=" + id +
+          ", waitTime=" + waitTime + ", operationTimeout=" + timeout + " expired.");
+      setException(ie); // includes a notify
+      return true;
+    } else {
+      return false;
+    }
+  }
+
+  public int remainingTime() {
+    if (timeout == 0) {
+      return Integer.MAX_VALUE;
+    }
+
+    int remaining = timeout - (int) (EnvironmentEdgeManager.currentTime() - getStartTime());
+    return remaining > 0 ? remaining : 0;
+  }
+
+  @Override
+  public String toString() {
+    return "callId: " + this.id + " methodName: " + this.md.getName() + " param {" +
+      (this.param != null? ProtobufUtil.getShortTextFormat(this.param): "") + "}";
+  }
+
+  /** Indicate when the call is complete and the
+   * value or error are available.  Notifies by default.  */
+  protected synchronized void callComplete() {
+    this.done = true;
+    notify();                                 // notify caller
+  }
+
+  /** Set the exception when there is an error.
+   * Notify the caller the call is done.
+   *
+   * @param error exception thrown by the call; either local or remote
+   */
+  public void setException(IOException error) {
+    this.error = error;
+    callComplete();
+  }
+
+  /**
+   * Set the return value when there is no error.
+   * Notify the caller the call is done.
+   *
+   * @param response return value of the call.
+   * @param cells Can be null
+   */
+  public void setResponse(Message response, final CellScanner cells) {
+    this.response = response;
+    this.cells = cells;
+    callComplete();
+  }
+
+  public long getStartTime() {
+    return this.startTime;
+  }
+}

hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/CallTimeoutException.java

@@ -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.
+ */
+package org.apache.hadoop.hbase.ipc;
+
+import org.apache.hadoop.hbase.classification.InterfaceAudience;
+import org.apache.hadoop.hbase.classification.InterfaceStability;
+
+import java.io.IOException;
+
+/**
+ * Client-side call timeout
+ */
+@SuppressWarnings("serial")
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
+public class CallTimeoutException extends IOException {
+  public CallTimeoutException(final String msg) {
+    super(msg);
+  }
+}

hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/ConnectionId.java

@@ -0,0 +1,78 @@
+/**
+ * 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.hbase.ipc;
+
+import org.apache.hadoop.hbase.classification.InterfaceAudience;
+import org.apache.hadoop.hbase.security.User;
+
+import java.net.InetSocketAddress;
+
+/**
+ * This class holds the address and the user ticket, etc. The client connections
+ * to servers are uniquely identified by <remoteAddress, ticket, serviceName>
+ */
+@InterfaceAudience.Private
+public class ConnectionId {
+  final InetSocketAddress address;
+  final User ticket;
+  private static final int PRIME = 16777619;
+  final String serviceName;
+
+  public ConnectionId(User ticket, String serviceName, InetSocketAddress address) {
+    this.address = address;
+    this.ticket = ticket;
+    this.serviceName = serviceName;
+  }
+
+  public String getServiceName() {
+    return this.serviceName;
+  }
+
+  public InetSocketAddress getAddress() {
+    return address;
+  }
+
+  public User getTicket() {
+    return ticket;
+  }
+
+  @Override
+  public String toString() {
+    return this.address.toString() + "/" + this.serviceName + "/" + this.ticket;
+  }
+
+  @Override
+  public boolean equals(Object obj) {
+   if (obj instanceof ConnectionId) {
+     ConnectionId id = (ConnectionId) obj;
+     return address.equals(id.address) &&
+            ((ticket != null && ticket.equals(id.ticket)) ||
+             (ticket == id.ticket)) &&
+             this.serviceName == id.serviceName;
+   }
+   return false;
+  }
+
+  @Override  // simply use the default Object#hashcode() ?
+  public int hashCode() {
+    int hashcode = (address.hashCode() +
+      PRIME * (PRIME * this.serviceName.hashCode() ^
+      (ticket == null ? 0 : ticket.hashCode())));
+    return hashcode;
+  }
+}

hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/FailedServerException.java

@@ -0,0 +1,37 @@
+/**
+ * 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.hbase.ipc;
+
+import org.apache.hadoop.hbase.HBaseIOException;
+import org.apache.hadoop.hbase.classification.InterfaceAudience;
+import org.apache.hadoop.hbase.classification.InterfaceStability;
+
+/**
+ * Indicates that we're trying to connect to a already known as dead server. We will want to
+ *  retry: we're getting this because the region location was wrong, or because
+ *  the server just died, in which case the retry loop will help us to wait for the
+ *  regions to recover.
+ */
+@SuppressWarnings("serial")
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
+public class FailedServerException extends HBaseIOException {
+  public FailedServerException(String s) {
+    super(s);
+  }
+}

hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/FailedServers.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.hbase.ipc;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.classification.InterfaceAudience;
+import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
+import org.apache.hadoop.hbase.util.Pair;
+
+import java.net.InetSocketAddress;
+import java.util.Iterator;
+import java.util.LinkedList;
+
+/**
+ * A class to manage a list of servers that failed recently.
+ */
+@InterfaceAudience.Private
+public class FailedServers {
+  private final LinkedList<Pair<Long, String>> failedServers = new
+      LinkedList<Pair<Long, String>>();
+  private final int recheckServersTimeout;
+
+  public FailedServers(Configuration conf) {
+    this.recheckServersTimeout = conf.getInt(
+        RpcClient.FAILED_SERVER_EXPIRY_KEY, RpcClient.FAILED_SERVER_EXPIRY_DEFAULT);
+  }
+
+  /**
+   * Add an address to the list of the failed servers list.
+   */
+  public synchronized void addToFailedServers(InetSocketAddress address) {
+    final long expiry = EnvironmentEdgeManager.currentTime() + recheckServersTimeout;
+    failedServers.addFirst(new Pair<Long, String>(expiry, address.toString()));
+  }
+
+  /**
+   * Check if the server should be considered as bad. Clean the old entries of the list.
+   *
+   * @return true if the server is in the failed servers list
+   */
+  public synchronized boolean isFailedServer(final InetSocketAddress address) {
+    if (failedServers.isEmpty()) {
+      return false;
+    }
+
+    final String lookup = address.toString();
+    final long now = EnvironmentEdgeManager.currentTime();
+
+    // iterate, looking for the search entry and cleaning expired entries
+    Iterator<Pair<Long, String>> it = failedServers.iterator();
+    while (it.hasNext()) {
+      Pair<Long, String> cur = it.next();
+      if (cur.getFirst() < now) {
+        it.remove();
+      } else {
+        if (lookup.equals(cur.getSecond())) {
+          return true;
+        }
+      }
+    }
+
+    return false;
+  }
+}

hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/IPCUtil.java

@@ -51,7 +51,7 @@ import com.google.protobuf.Message;
  * Utility to help ipc'ing.
  */
 @InterfaceAudience.Private
-class IPCUtil {
+public class IPCUtil {
   public static final Log LOG = LogFactory.getLog(IPCUtil.class);
   /**
    * How much we think the decompressor will expand the original compressed content.
@@ -60,7 +60,7 @@ class IPCUtil {
   private final int cellBlockBuildingInitialBufferSize;
   private final Configuration conf;
 
-  IPCUtil(final Configuration conf) {
+  public IPCUtil(final Configuration conf) {
     super();
     this.conf = conf;
     this.cellBlockDecompressionMultiplier =
@@ -81,14 +81,14 @@ class IPCUtil {
    * <code>compressor</code>.
    * @param codec
    * @param compressor
-   * @Param cellScanner
+   * @param cellScanner
    * @return Null or byte buffer filled with a cellblock filled with passed-in Cells encoded using
    * passed in <code>codec</code> and/or <code>compressor</code>; the returned buffer has been
    * flipped and is ready for reading.  Use limit to find total size.
    * @throws IOException
    */
   @SuppressWarnings("resource")
-  ByteBuffer buildCellBlock(final Codec codec, final CompressionCodec compressor,
+  public ByteBuffer buildCellBlock(final Codec codec, final CompressionCodec compressor,
     final CellScanner cellScanner)
   throws IOException {
     if (cellScanner == null) return null;
@@ -145,7 +145,7 @@ class IPCUtil {
    * @return CellScanner to work against the content of <code>cellBlock</code>
    * @throws IOException
    */
-  CellScanner createCellScanner(final Codec codec, final CompressionCodec compressor,
+  public CellScanner createCellScanner(final Codec codec, final CompressionCodec compressor,
       final byte [] cellBlock)
   throws IOException {
     return createCellScanner(codec, compressor, cellBlock, 0, cellBlock.length);
@@ -159,7 +159,7 @@ class IPCUtil {
    * @return CellScanner to work against the content of <code>cellBlock</code>
    * @throws IOException
    */
-  CellScanner createCellScanner(final Codec codec, final CompressionCodec compressor,
+  public CellScanner createCellScanner(final Codec codec, final CompressionCodec compressor,
       final byte [] cellBlock, final int offset, final int length)
   throws IOException {
     // If compressed, decompress it first before passing it on else we will leak compression
@@ -200,7 +200,7 @@ class IPCUtil {
    * @return The passed in Message serialized with delimiter.  Return null if <code>m</code> is null
    * @throws IOException
    */
-  static ByteBuffer getDelimitedMessageAsByteBuffer(final Message m) throws IOException {
+  public static ByteBuffer getDelimitedMessageAsByteBuffer(final Message m) throws IOException {
     if (m == null) return null;
     int serializedSize = m.getSerializedSize();
     int vintSize = CodedOutputStream.computeRawVarint32Size(serializedSize);
@@ -223,7 +223,7 @@ class IPCUtil {
    * @return Total number of bytes written.
    * @throws IOException
    */
-  static int write(final OutputStream dos, final Message header, final Message param,
+  public static int write(final OutputStream dos, final Message header, final Message param,
       final ByteBuffer cellBlock)
   throws IOException {
     // Must calculate total size and write that first so other side can read it all in in one
@@ -255,7 +255,7 @@ class IPCUtil {
    * @param len
    * @throws IOException
    */
-  static void readChunked(final DataInput in, byte[] dest, int offset, int len)
+  public static void readChunked(final DataInput in, byte[] dest, int offset, int len)
       throws IOException {
     int maxRead = 8192;
 
@@ -265,11 +265,9 @@ class IPCUtil {
   }
 
   /**
-   * @param header
-   * @param body
    * @return Size on the wire when the two messages are written with writeDelimitedTo
    */
-  static int getTotalSizeWhenWrittenDelimited(Message ... messages) {
+  public static int getTotalSizeWhenWrittenDelimited(Message ... messages) {
     int totalSize = 0;
     for (Message m: messages) {
       if (m == null) continue;

hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/RpcClientFactory.java

@@ -0,0 +1,70 @@
+/**
+ * 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.hbase.ipc;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.classification.InterfaceAudience;
+import org.apache.hadoop.hbase.util.ReflectionUtils;
+
+import java.net.SocketAddress;
+
+/**
+ * Factory to create a {@link org.apache.hadoop.hbase.ipc.RpcClient}
+ */
+@InterfaceAudience.Private
+public final class RpcClientFactory {
+
+  public static final String CUSTOM_RPC_CLIENT_IMPL_CONF_KEY = "hbase.rpc.client.impl";
+
+  /**
+   * Private Constructor
+   */
+  private RpcClientFactory() {
+  }
+
+  /**
+   * Creates a new RpcClient by the class defined in the configuration or falls back to
+   * RpcClientImpl
+   * @param conf configuration
+   * @param clusterId the cluster id
+   * @return newly created RpcClient
+   */
+  public static RpcClient createClient(Configuration conf, String clusterId) {
+    return createClient(conf, clusterId, null);
+  }
+
+  /**
+   * Creates a new RpcClient by the class defined in the configuration or falls back to
+   * RpcClientImpl
+   * @param conf configuration
+   * @param clusterId the cluster id
+   * @param localAddr client socket bind address.
+   * @return newly created RpcClient
+   */
+  public static RpcClient createClient(Configuration conf, String clusterId,
+      SocketAddress localAddr) {
+    String rpcClientClass =
+        conf.get(CUSTOM_RPC_CLIENT_IMPL_CONF_KEY,
+          RpcClientImpl.class.getName());
+    return ReflectionUtils.instantiateWithCustomCtor(
+        rpcClientClass,
+        new Class[] { Configuration.class, String.class, SocketAddress.class },
+        new Object[] { conf, clusterId, localAddr }
+    );
+  }
+}

hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/MetaTableLocator.java

@@ -39,7 +39,7 @@ import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.client.HConnection;
 import org.apache.hadoop.hbase.client.RetriesExhaustedException;
 import org.apache.hadoop.hbase.exceptions.DeserializationException;
-import org.apache.hadoop.hbase.ipc.RpcClient;
+import org.apache.hadoop.hbase.ipc.FailedServerException;
 import org.apache.hadoop.hbase.ipc.ServerNotRunningYetException;
 import org.apache.hadoop.hbase.master.RegionState;
 import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
@@ -316,7 +316,7 @@ public class MetaTableLocator {
       LOG.debug("Exception connecting to " + sn);
     } catch (UnknownHostException e) {
       LOG.debug("Unknown host exception connecting to  " + sn);
-    } catch (RpcClient.FailedServerException e) {
+    } catch (FailedServerException e) {
       if (LOG.isDebugEnabled()) {
         LOG.debug("Server " + sn + " is in failed server list.");
       }

hbase-server/src/main/java/org/apache/hadoop/hbase/ipc/RpcServer.java

@@ -148,7 +148,7 @@ import com.google.protobuf.TextFormat;
  * CallRunner#run executes the call.  When done, asks the included Call to put itself on new
  * queue for Responder to pull from and return result to client.
  *
- * @see RpcClient
+ * @see RpcClientImpl
  */
 @InterfaceAudience.LimitedPrivate({HBaseInterfaceAudience.COPROC, HBaseInterfaceAudience.PHOENIX})
 @InterfaceStability.Evolving

hbase-server/src/main/java/org/apache/hadoop/hbase/master/AssignmentManager.java

@@ -64,8 +64,8 @@ import org.apache.hadoop.hbase.client.TableState;
 import org.apache.hadoop.hbase.executor.EventHandler;
 import org.apache.hadoop.hbase.executor.EventType;
 import org.apache.hadoop.hbase.executor.ExecutorService;
+import org.apache.hadoop.hbase.ipc.FailedServerException;
 import org.apache.hadoop.hbase.ipc.RpcClient;
-import org.apache.hadoop.hbase.ipc.RpcClient.FailedServerException;
 import org.apache.hadoop.hbase.ipc.ServerNotRunningYetException;
 import org.apache.hadoop.hbase.master.RegionState.State;
 import org.apache.hadoop.hbase.master.balancer.FavoredNodeAssignmentHelper;

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java

@@ -78,7 +78,6 @@ import org.apache.hadoop.hbase.client.ConnectionFactory;
 import org.apache.hadoop.hbase.client.ConnectionUtils;
 import org.apache.hadoop.hbase.conf.ConfigurationManager;
 import org.apache.hadoop.hbase.client.ClusterConnection;
-import org.apache.hadoop.hbase.client.ConnectionFactory;
 import org.apache.hadoop.hbase.coordination.BaseCoordinatedStateManager;
 import org.apache.hadoop.hbase.coordination.SplitLogWorkerCoordination;
 import org.apache.hadoop.hbase.coprocessor.CoprocessorHost;
@@ -91,6 +90,7 @@ import org.apache.hadoop.hbase.fs.HFileSystem;
 import org.apache.hadoop.hbase.http.InfoServer;
 import org.apache.hadoop.hbase.io.hfile.CacheConfig;
 import org.apache.hadoop.hbase.ipc.RpcClient;
+import org.apache.hadoop.hbase.ipc.RpcClientFactory;
 import org.apache.hadoop.hbase.ipc.RpcServerInterface;
 import org.apache.hadoop.hbase.ipc.ServerNotRunningYetException;
 import org.apache.hadoop.hbase.ipc.ServerRpcController;
@@ -782,10 +782,11 @@ public class HRegionServer extends HasThread implements
     rsQuotaManager = new RegionServerQuotaManager(this);
 
     // Setup RPC client for master communication
-    rpcClient = new RpcClient(conf, clusterId, new InetSocketAddress(
+    rpcClient = RpcClientFactory.createClient(conf, clusterId, new InetSocketAddress(
         rpcServices.isa.getAddress(), 0));
 
-    int storefileRefreshPeriod = conf.getInt(StorefileRefresherChore.REGIONSERVER_STOREFILE_REFRESH_PERIOD
+    int storefileRefreshPeriod = conf.getInt(
+        StorefileRefresherChore.REGIONSERVER_STOREFILE_REFRESH_PERIOD
       , StorefileRefresherChore.DEFAULT_REGIONSERVER_STOREFILE_REFRESH_PERIOD);
     if (storefileRefreshPeriod > 0) {
       this.storefileRefresher = new StorefileRefresherChore(storefileRefreshPeriod, this, this);
@@ -994,7 +995,7 @@ public class HRegionServer extends HasThread implements
       this.rssStub = null;
     }
     if (this.rpcClient != null) {
-      this.rpcClient.stop();
+      this.rpcClient.close();
     }
     if (this.leases != null) {
       this.leases.close();

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestClientScannerRPCTimeout.java

@@ -30,7 +30,7 @@ import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.MiniHBaseCluster.MiniHBaseClusterRegionServer;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.CoordinatedStateManager;
-import org.apache.hadoop.hbase.ipc.RpcClient;
+import org.apache.hadoop.hbase.ipc.AbstractRpcClient;
 import org.apache.hadoop.hbase.ipc.RpcServer;
 import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.ScanRequest;
 import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.ScanResponse;
@@ -65,7 +65,7 @@ public class TestClientScannerRPCTimeout {
   @BeforeClass
   public static void setUpBeforeClass() throws Exception {
     ((Log4JLogger)RpcServer.LOG).getLogger().setLevel(Level.ALL);
-    ((Log4JLogger)RpcClient.LOG).getLogger().setLevel(Level.ALL);
+    ((Log4JLogger)AbstractRpcClient.LOG).getLogger().setLevel(Level.ALL);
     ((Log4JLogger)ScannerCallable.LOG).getLogger().setLevel(Level.ALL);
     Configuration conf = TEST_UTIL.getConfiguration();
     // Don't report so often so easier to see other rpcs

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestClientTimeouts.java

@@ -22,6 +22,7 @@ package org.apache.hadoop.hbase.client;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
+import java.net.SocketAddress;
 import java.net.SocketTimeoutException;
 import java.util.Random;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -35,6 +36,8 @@ import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.MasterNotRunningException;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.ipc.RpcClient;
+import org.apache.hadoop.hbase.ipc.RpcClientFactory;
+import org.apache.hadoop.hbase.ipc.RpcClientImpl;
 import org.apache.hadoop.hbase.security.User;
 import org.apache.hadoop.hbase.testclassification.ClientTests;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
@@ -61,6 +64,10 @@ public class TestClientTimeouts {
   @BeforeClass
   public static void setUpBeforeClass() throws Exception {
     TEST_UTIL.startMiniCluster(SLAVES);
+    // Set the custom RPC client with random timeouts as the client
+    TEST_UTIL.getConfiguration().set(
+        RpcClientFactory.CUSTOM_RPC_CLIENT_IMPL_CONF_KEY,
+        RandomTimeoutRpcClient.class.getName());
   }
 
   /**
@@ -81,7 +88,9 @@ public class TestClientTimeouts {
     Connection lastConnection = null;
     boolean lastFailed = false;
     int initialInvocations = RandomTimeoutBlockingRpcChannel.invokations.get();
-    RpcClient rpcClient = newRandomTimeoutRpcClient();
+    RandomTimeoutRpcClient rpcClient = (RandomTimeoutRpcClient) RpcClientFactory
+        .createClient(TEST_UTIL.getConfiguration(), TEST_UTIL.getClusterKey());
+
     try {
       for (int i = 0; i < 5 || (lastFailed && i < 100); ++i) {
         lastFailed = false;
@@ -94,13 +103,6 @@ public class TestClientTimeouts {
           Connection connection = admin.getConnection();
           assertFalse(connection == lastConnection);
           lastConnection = connection;
-          // Override the connection's rpc client for timeout testing
-          RpcClient oldRpcClient =
-            ((ConnectionManager.HConnectionImplementation)connection).setRpcClient(
-              rpcClient);
-          if (oldRpcClient != null) {
-            oldRpcClient.stop();
-          }
           // run some admin commands
           HBaseAdmin.checkHBaseAvailable(conf);
           admin.setBalancerRunning(false, false);
@@ -111,7 +113,8 @@ public class TestClientTimeouts {
         } finally {
           admin.close();
           if (admin.getConnection().isClosed()) {
-            rpcClient = newRandomTimeoutRpcClient();
+            rpcClient = (RandomTimeoutRpcClient) RpcClientFactory
+                .createClient(TEST_UTIL.getConfiguration(), TEST_UTIL.getClusterKey());
           }
         }
       }
@@ -119,31 +122,36 @@ public class TestClientTimeouts {
       assertFalse(lastFailed);
       assertTrue(RandomTimeoutBlockingRpcChannel.invokations.get() > initialInvocations);
     } finally {
-      rpcClient.stop();
+      rpcClient.close();
     }
   }
 
-  private static RpcClient newRandomTimeoutRpcClient() {
-    return new RpcClient(
-        TEST_UTIL.getConfiguration(), TEST_UTIL.getClusterKey()) {
+  /**
+   * Rpc Channel implementation with RandomTimeoutBlockingRpcChannel
+   */
+  public static class RandomTimeoutRpcClient extends RpcClientImpl{
+    public RandomTimeoutRpcClient(Configuration conf, String clusterId, SocketAddress localAddr) {
+      super(conf, clusterId, localAddr);
+    }
+
     // Return my own instance, one that does random timeouts
     @Override
     public BlockingRpcChannel createBlockingRpcChannel(ServerName sn,
         User ticket, int rpcTimeout) {
       return new RandomTimeoutBlockingRpcChannel(this, sn, ticket, rpcTimeout);
     }
-    };
   }
 
   /**
    * Blocking rpc channel that goes via hbase rpc.
    */
-  static class RandomTimeoutBlockingRpcChannel extends RpcClient.BlockingRpcChannelImplementation {
+  static class RandomTimeoutBlockingRpcChannel
+      extends RpcClientImpl.BlockingRpcChannelImplementation {
     private static final Random RANDOM = new Random(System.currentTimeMillis());
     public static final double CHANCE_OF_TIMEOUT = 0.3;
     private static AtomicInteger invokations = new AtomicInteger();
 
-    RandomTimeoutBlockingRpcChannel(final RpcClient rpcClient, final ServerName sn,
+    RandomTimeoutBlockingRpcChannel(final RpcClientImpl rpcClient, final ServerName sn,
         final User ticket, final int rpcTimeout) {
       super(rpcClient, sn, ticket, rpcTimeout);
     }

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestFromClientSideNoCodec.java

@@ -25,7 +25,7 @@ import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellScanner;
 import org.apache.hadoop.hbase.HBaseTestingUtility;
-import org.apache.hadoop.hbase.ipc.RpcClient;
+import org.apache.hadoop.hbase.ipc.AbstractRpcClient;
 import org.apache.hadoop.hbase.testclassification.ClientTests;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
 import org.apache.hadoop.hbase.util.Bytes;
@@ -97,7 +97,7 @@ public class TestFromClientSideNoCodec {
   public void testNoCodec() {
     Configuration c = new Configuration();
     c.set("hbase.client.default.rpc.codec", "");
-    String codec = RpcClient.getDefaultCodec(c);
+    String codec = AbstractRpcClient.getDefaultCodec(c);
     assertTrue(codec == null || codec.length() == 0);
   }
 }

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestHCM.java

@@ -394,7 +394,7 @@ public class TestHCM {
 
     LOG.info("Going to cancel connections. connection=" + conn.toString() + ", sn=" + sn);
     for (int i = 0; i < 5000; i++) {
-      rpcClient.cancelConnections(sn.getHostname(), sn.getPort());
+      rpcClient.cancelConnections(sn);
       Thread.sleep(5);
     }
 

hbase-server/src/test/java/org/apache/hadoop/hbase/filter/FilterTestingCluster.java

@@ -41,7 +41,7 @@ import org.apache.hadoop.hbase.client.HBaseAdmin;
 import org.apache.hadoop.hbase.client.HTable;
 import org.apache.hadoop.hbase.client.ScannerCallable;
 import org.apache.hadoop.hbase.client.Table;
-import org.apache.hadoop.hbase.ipc.RpcClient;
+import org.apache.hadoop.hbase.ipc.AbstractRpcClient;
 import org.apache.hadoop.hbase.ipc.RpcServer;
 import org.apache.hadoop.hbase.testclassification.FilterTests;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
@@ -115,7 +115,7 @@ public class FilterTestingCluster {
   @BeforeClass
   public static void setUp() throws Exception {
     ((Log4JLogger)RpcServer.LOG).getLogger().setLevel(Level.ALL);
-    ((Log4JLogger)RpcClient.LOG).getLogger().setLevel(Level.ALL);
+    ((Log4JLogger)AbstractRpcClient.LOG).getLogger().setLevel(Level.ALL);
     ((Log4JLogger)ScannerCallable.LOG).getLogger().setLevel(Level.ALL);
     TEST_UTIL.startMiniCluster(1);
     initialize(TEST_UTIL.getConfiguration());

hbase-server/src/test/java/org/apache/hadoop/hbase/ipc/TestDelayedRpc.java

@@ -89,7 +89,8 @@ public class TestDelayedRpc {
         conf,
         new FifoRpcScheduler(conf, 1));
     rpcServer.start();
-    RpcClient rpcClient = new RpcClient(conf, HConstants.DEFAULT_CLUSTER_ID.toString());
+    RpcClient rpcClient = RpcClientFactory.createClient(
+        conf, HConstants.DEFAULT_CLUSTER_ID.toString());
     try {
       BlockingRpcChannel channel = rpcClient.createBlockingRpcChannel(
           ServerName.valueOf(rpcServer.getListenerAddress().getHostName(),
@@ -118,7 +119,7 @@ public class TestDelayedRpc {
       assertEquals(UNDELAYED, results.get(1).intValue());
       assertEquals(results.get(2).intValue(), delayReturnValue ? DELAYED :  0xDEADBEEF);
     } finally {
-      rpcClient.stop();
+      rpcClient.close();
     }
   }
 
@@ -170,7 +171,8 @@ public class TestDelayedRpc {
         conf,
         new FifoRpcScheduler(conf, 1));
     rpcServer.start();
-    RpcClient rpcClient = new RpcClient(conf, HConstants.DEFAULT_CLUSTER_ID.toString());
+    RpcClient rpcClient = RpcClientFactory.createClient(
+        conf, HConstants.DEFAULT_CLUSTER_ID.toString());
     try {
       BlockingRpcChannel channel = rpcClient.createBlockingRpcChannel(
           ServerName.valueOf(rpcServer.getListenerAddress().getHostName(),
@@ -200,7 +202,7 @@ public class TestDelayedRpc {
 
       log.removeAppender(listAppender);
     } finally {
-      rpcClient.stop();
+      rpcClient.close();
     }
   }
 
@@ -293,7 +295,8 @@ public class TestDelayedRpc {
         conf,
         new FifoRpcScheduler(conf, 1));
     rpcServer.start();
-    RpcClient rpcClient = new RpcClient(conf, HConstants.DEFAULT_CLUSTER_ID.toString());
+    RpcClient rpcClient = RpcClientFactory.createClient(
+        conf, HConstants.DEFAULT_CLUSTER_ID.toString());
     try {
       BlockingRpcChannel channel = rpcClient.createBlockingRpcChannel(
           ServerName.valueOf(rpcServer.getListenerAddress().getHostName(),
@@ -323,7 +326,7 @@ public class TestDelayedRpc {
       }
       assertTrue(caughtException);
     } finally {
-      rpcClient.stop();
+      rpcClient.close();
     }
   }
 

hbase-server/src/test/java/org/apache/hadoop/hbase/ipc/TestHBaseClient.java

@@ -36,7 +36,7 @@ public class TestHBaseClient {
   public void testFailedServer(){
     ManualEnvironmentEdge ee = new ManualEnvironmentEdge();
     EnvironmentEdgeManager.injectEdge(  ee );
-    RpcClient.FailedServers fs = new RpcClient.FailedServers(new Configuration());
+    FailedServers fs = new FailedServers(new Configuration());
 
     InetSocketAddress ia = InetSocketAddress.createUnresolved("bad", 12);
     InetSocketAddress ia2 = InetSocketAddress.createUnresolved("bad", 12);  // same server as ia

hbase-server/src/test/java/org/apache/hadoop/hbase/ipc/TestIPC.java

@@ -178,7 +178,7 @@ public class TestIPC {
   @Test
   public void testNoCodec() throws InterruptedException, IOException {
     Configuration conf = HBaseConfiguration.create();
-    RpcClient client = new RpcClient(conf, HConstants.CLUSTER_ID_DEFAULT) {
+    RpcClientImpl client = new RpcClientImpl(conf, HConstants.CLUSTER_ID_DEFAULT) {
       @Override
       Codec getCodec() {
         return null;
@@ -197,7 +197,7 @@ public class TestIPC {
       // Silly assertion that the message is in the returned pb.
       assertTrue(r.getFirst().toString().contains(message));
     } finally {
-      client.stop();
+      client.close();
       rpcServer.stop();
     }
   }
@@ -216,10 +216,10 @@ public class TestIPC {
   throws IOException, InterruptedException, SecurityException, NoSuchMethodException {
     Configuration conf = new Configuration(HBaseConfiguration.create());
     conf.set("hbase.client.rpc.compressor", GzipCodec.class.getCanonicalName());
-    doSimpleTest(conf, new RpcClient(conf, HConstants.CLUSTER_ID_DEFAULT));
+    doSimpleTest(conf, new RpcClientImpl(conf, HConstants.CLUSTER_ID_DEFAULT));
   }
 
-  private void doSimpleTest(final Configuration conf, final RpcClient client)
+  private void doSimpleTest(final Configuration conf, final RpcClientImpl client)
   throws InterruptedException, IOException {
     TestRpcServer rpcServer = new TestRpcServer();
     List<Cell> cells = new ArrayList<Cell>();
@@ -239,7 +239,7 @@ public class TestIPC {
       }
       assertEquals(count, index);
     } finally {
-      client.stop();
+      client.close();
       rpcServer.stop();
     }
   }
@@ -258,7 +258,7 @@ public class TestIPC {
     }).when(spyFactory).createSocket();
 
     TestRpcServer rpcServer = new TestRpcServer();
-    RpcClient client = new RpcClient(conf, HConstants.CLUSTER_ID_DEFAULT, spyFactory);
+    RpcClientImpl client = new RpcClientImpl(conf, HConstants.CLUSTER_ID_DEFAULT, spyFactory);
     try {
       rpcServer.start();
       InetSocketAddress address = rpcServer.getListenerAddress();
@@ -270,7 +270,7 @@ public class TestIPC {
       LOG.info("Caught expected exception: " + e.toString());
       assertTrue(StringUtils.stringifyException(e).contains("Injected fault"));
     } finally {
-      client.stop();
+      client.close();
       rpcServer.stop();
     }
   }
@@ -281,7 +281,7 @@ public class TestIPC {
     RpcScheduler scheduler = spy(new FifoRpcScheduler(CONF, 1));
     RpcServer rpcServer = new TestRpcServer(scheduler);
     verify(scheduler).init((RpcScheduler.Context) anyObject());
-    RpcClient client = new RpcClient(CONF, HConstants.CLUSTER_ID_DEFAULT);
+    RpcClientImpl client = new RpcClientImpl(CONF, HConstants.CLUSTER_ID_DEFAULT);
     try {
       rpcServer.start();
       verify(scheduler).start();
@@ -312,7 +312,7 @@ public class TestIPC {
     TestRpcServer rpcServer = new TestRpcServer();
     MethodDescriptor md = SERVICE.getDescriptorForType().findMethodByName("echo");
     EchoRequestProto param = EchoRequestProto.newBuilder().setMessage("hello").build();
-    RpcClient client = new RpcClient(conf, HConstants.CLUSTER_ID_DEFAULT);
+    RpcClientImpl client = new RpcClientImpl(conf, HConstants.CLUSTER_ID_DEFAULT);
     KeyValue kv = KeyValueUtil.ensureKeyValue(BIG_CELL);
     Put p = new Put(kv.getRow());
     for (int i = 0; i < cellcount; i++) {
@@ -354,7 +354,7 @@ public class TestIPC {
       LOG.info("Cycled " + cycles + " time(s) with " + cellcount + " cell(s) in " +
          (System.currentTimeMillis() - startTime) + "ms");
     } finally {
-      client.stop();
+      client.close();
       rpcServer.stop();
     }
   }

hbase-server/src/test/java/org/apache/hadoop/hbase/ipc/TestProtoBufRpc.java

@@ -112,7 +112,7 @@ public class TestProtoBufRpc {
 
   @Test
   public void testProtoBufRpc() throws Exception {
-    RpcClient rpcClient = new RpcClient(conf, HConstants.CLUSTER_ID_DEFAULT);
+    RpcClient rpcClient = RpcClientFactory.createClient(conf, HConstants.CLUSTER_ID_DEFAULT);
     try {
       BlockingRpcChannel channel = rpcClient.createBlockingRpcChannel(
           ServerName.valueOf(this.isa.getHostName(), this.isa.getPort(), System.currentTimeMillis()),
@@ -136,7 +136,7 @@ public class TestProtoBufRpc {
       } catch (ServiceException e) {
       }
     } finally {
-      rpcClient.stop();
+      rpcClient.close();
     }
   }
 }

hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestHMasterRPCException.java

@@ -29,6 +29,7 @@ import org.apache.hadoop.hbase.*;
 import org.apache.hadoop.hbase.CoordinatedStateManager;
 import org.apache.hadoop.hbase.CoordinatedStateManagerFactory;
 import org.apache.hadoop.hbase.ipc.RpcClient;
+import org.apache.hadoop.hbase.ipc.RpcClientFactory;
 import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos;
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.IsMasterRunningRequest;
@@ -53,7 +54,7 @@ public class TestHMasterRPCException {
     CoordinatedStateManager cp = CoordinatedStateManagerFactory.getCoordinatedStateManager(conf);
     HMaster hm = new HMaster(conf, cp);
     ServerName sm = hm.getServerName();
-    RpcClient rpcClient = new RpcClient(conf, HConstants.CLUSTER_ID_DEFAULT);
+    RpcClient rpcClient = RpcClientFactory.createClient(conf, HConstants.CLUSTER_ID_DEFAULT);
     try {
       int i = 0;
       //retry the RPC a few times; we have seen SocketTimeoutExceptions if we
@@ -88,7 +89,7 @@ public class TestHMasterRPCException {
       }
       fail();
     } finally {
-      rpcClient.stop();
+      rpcClient.close();
     }
   }
 }

hbase-server/src/test/java/org/apache/hadoop/hbase/security/TestSecureRPC.java

@@ -35,6 +35,7 @@ import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.CommonConfigurationKeys;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.ServerName;
+import org.apache.hadoop.hbase.ipc.RpcClientFactory;
 import org.apache.hadoop.hbase.testclassification.SecurityTests;
 import org.apache.hadoop.hbase.testclassification.SmallTests;
 import org.apache.hadoop.hbase.ipc.FifoRpcScheduler;
@@ -99,7 +100,8 @@ public class TestSecureRPC {
         Lists.newArrayList(new RpcServer.BlockingServiceAndInterface(service, null)),
           isa, conf, new FifoRpcScheduler(conf, 1));
     rpcServer.start();
-    RpcClient rpcClient = new RpcClient(conf, HConstants.DEFAULT_CLUSTER_ID.toString());
+    RpcClient rpcClient = RpcClientFactory
+        .createClient(conf, HConstants.DEFAULT_CLUSTER_ID.toString());
     try {
       BlockingRpcChannel channel = rpcClient.createBlockingRpcChannel(
           ServerName.valueOf(rpcServer.getListenerAddress().getHostName(),
@@ -115,7 +117,7 @@ public class TestSecureRPC {
 
       assertEquals(0xDEADBEEF, results.get(0).intValue());
     } finally {
-      rpcClient.stop();
+      rpcClient.close();
     }
   }
 }

hbase-server/src/test/java/org/apache/hadoop/hbase/security/token/TestTokenAuthentication.java

@@ -51,6 +51,7 @@ import org.apache.hadoop.hbase.ipc.BlockingRpcCallback;
 import org.apache.hadoop.hbase.ipc.FifoRpcScheduler;
 import org.apache.hadoop.hbase.ipc.RequestContext;
 import org.apache.hadoop.hbase.ipc.RpcClient;
+import org.apache.hadoop.hbase.ipc.RpcClientFactory;
 import org.apache.hadoop.hbase.ipc.RpcServer;
 import org.apache.hadoop.hbase.ipc.RpcServer.BlockingServiceAndInterface;
 import org.apache.hadoop.hbase.ipc.RpcServerInterface;
@@ -400,7 +401,7 @@ public class TestTokenAuthentication {
     testuser.doAs(new PrivilegedExceptionAction<Object>() {
       public Object run() throws Exception {
         Configuration c = server.getConfiguration();
-        RpcClient rpcClient = new RpcClient(c, clusterId.toString());
+        RpcClient rpcClient = RpcClientFactory.createClient(c, clusterId.toString());
         ServerName sn =
             ServerName.valueOf(server.getAddress().getHostName(), server.getAddress().getPort(),
                 System.currentTimeMillis());
@@ -416,7 +417,7 @@ public class TestTokenAuthentication {
           String authMethod = response.getAuthMethod();
           assertEquals("TOKEN", authMethod);
         } finally {
-          rpcClient.stop();
+          rpcClient.close();
         }
         return null;
       }

hbase-server/src/test/java/org/apache/hadoop/hbase/snapshot/TestFlushSnapshotFromClient.java

@@ -43,7 +43,7 @@ import org.apache.hadoop.hbase.TableNotFoundException;
 import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.client.HTable;
 import org.apache.hadoop.hbase.client.ScannerCallable;
-import org.apache.hadoop.hbase.ipc.RpcClient;
+import org.apache.hadoop.hbase.ipc.AbstractRpcClient;
 import org.apache.hadoop.hbase.ipc.RpcServer;
 import org.apache.hadoop.hbase.master.HMaster;
 import org.apache.hadoop.hbase.master.snapshot.SnapshotManager;
@@ -88,7 +88,7 @@ public class TestFlushSnapshotFromClient {
     // Uncomment the following lines if more verbosity is needed for
     // debugging (see HBASE-12285 for details).
     //((Log4JLogger)RpcServer.LOG).getLogger().setLevel(Level.ALL);
-    //((Log4JLogger)RpcClient.LOG).getLogger().setLevel(Level.ALL);
+    //((Log4JLogger)AbstractRpcClient.LOG).getLogger().setLevel(Level.ALL);
     //((Log4JLogger)ScannerCallable.LOG).getLogger().setLevel(Level.ALL);
     setupConf(UTIL.getConfiguration());
     UTIL.startMiniCluster(NUM_RS);