001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License. You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019 package org.apache.hadoop.yarn.client;
020
021 import java.io.IOException;
022 import java.net.InetSocketAddress;
023 import java.security.PrivilegedAction;
024
025 import org.apache.commons.logging.Log;
026 import org.apache.commons.logging.LogFactory;
027 import org.apache.hadoop.classification.InterfaceAudience;
028 import org.apache.hadoop.classification.InterfaceStability;
029 import org.apache.hadoop.conf.Configuration;
030 import org.apache.hadoop.security.UserGroupInformation;
031 import org.apache.hadoop.yarn.ipc.YarnRPC;
032
033 @InterfaceAudience.Public
034 @InterfaceStability.Evolving
035 @SuppressWarnings("unchecked")
036 public class AHSProxy<T> {
037
038 private static final Log LOG = LogFactory.getLog(AHSProxy.class);
039
040 public static <T> T createAHSProxy(final Configuration conf,
041 final Class<T> protocol, InetSocketAddress ahsAddress) throws IOException {
042 LOG.info("Connecting to Application History server at " + ahsAddress);
043 return (T) getProxy(conf, protocol, ahsAddress);
044 }
045
046 protected static <T> T getProxy(final Configuration conf,
047 final Class<T> protocol, final InetSocketAddress rmAddress)
048 throws IOException {
049 return UserGroupInformation.getCurrentUser().doAs(
050 new PrivilegedAction<T>() {
051 @Override
052 public T run() {
053 return (T) YarnRPC.create(conf).getProxy(protocol, rmAddress, conf);
054 }
055 });
056 }
057 }