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 package org.apache.hadoop.ha; 019 020 import java.io.IOException; 021 import java.net.InetSocketAddress; 022 import java.util.Map; 023 024 import javax.net.SocketFactory; 025 026 import org.apache.hadoop.classification.InterfaceAudience; 027 import org.apache.hadoop.classification.InterfaceStability; 028 import org.apache.hadoop.conf.Configuration; 029 import org.apache.hadoop.fs.CommonConfigurationKeysPublic; 030 import org.apache.hadoop.ha.protocolPB.HAServiceProtocolClientSideTranslatorPB; 031 import org.apache.hadoop.net.NetUtils; 032 033 import com.google.common.collect.Maps; 034 035 /** 036 * Represents a target of the client side HA administration commands. 037 */ 038 @InterfaceAudience.Public 039 @InterfaceStability.Evolving 040 public abstract class HAServiceTarget { 041 042 private static final String HOST_SUBST_KEY = "host"; 043 private static final String PORT_SUBST_KEY = "port"; 044 private static final String ADDRESS_SUBST_KEY = "address"; 045 046 /** 047 * @return the IPC address of the target node. 048 */ 049 public abstract InetSocketAddress getAddress(); 050 051 /** 052 * @return a Fencer implementation configured for this target node 053 */ 054 public abstract NodeFencer getFencer(); 055 056 /** 057 * @throws BadFencingConfigurationException if the fencing configuration 058 * appears to be invalid. This is divorced from the above 059 * {@link #getFencer()} method so that the configuration can be checked 060 * during the pre-flight phase of failover. 061 */ 062 public abstract void checkFencingConfigured() 063 throws BadFencingConfigurationException; 064 065 /** 066 * @return a proxy to connect to the target HA Service. 067 */ 068 public HAServiceProtocol getProxy(Configuration conf, int timeoutMs) 069 throws IOException { 070 Configuration confCopy = new Configuration(conf); 071 // Lower the timeout so we quickly fail to connect 072 confCopy.setInt(CommonConfigurationKeysPublic.IPC_CLIENT_CONNECT_MAX_RETRIES_KEY, 1); 073 SocketFactory factory = NetUtils.getDefaultSocketFactory(confCopy); 074 return new HAServiceProtocolClientSideTranslatorPB( 075 getAddress(), 076 confCopy, factory, timeoutMs); 077 } 078 079 public final Map<String, String> getFencingParameters() { 080 Map<String, String> ret = Maps.newHashMap(); 081 addFencingParameters(ret); 082 return ret; 083 } 084 085 /** 086 * Hook to allow subclasses to add any parameters they would like to 087 * expose to fencing implementations/scripts. Fencing methods are free 088 * to use this map as they see fit -- notably, the shell script 089 * implementation takes each entry, prepends 'target_', substitutes 090 * '_' for '.', and adds it to the environment of the script. 091 * 092 * Subclass implementations should be sure to delegate to the superclass 093 * implementation as well as adding their own keys. 094 * 095 * @param ret map which can be mutated to pass parameters to the fencer 096 */ 097 protected void addFencingParameters(Map<String, String> ret) { 098 ret.put(ADDRESS_SUBST_KEY, String.valueOf(getAddress())); 099 ret.put(HOST_SUBST_KEY, getAddress().getHostName()); 100 ret.put(PORT_SUBST_KEY, String.valueOf(getAddress().getPort())); 101 } 102 }