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.hdfs.server.common;
019
020 import java.io.DataInput;
021 import java.io.DataOutput;
022 import java.io.IOException;
023
024 import org.apache.hadoop.classification.InterfaceAudience;
025 import org.apache.hadoop.hdfs.server.namenode.MetaRecoveryContext;
026
027 /************************************
028 * Some handy internal HDFS constants
029 *
030 ************************************/
031
032 @InterfaceAudience.Private
033 public final class HdfsServerConstants {
034 /* Hidden constructor */
035 private HdfsServerConstants() { }
036
037 /**
038 * Type of the node
039 */
040 static public enum NodeType {
041 NAME_NODE,
042 DATA_NODE;
043 }
044
045 /** Startup options */
046 static public enum StartupOption{
047 FORMAT ("-format"),
048 CLUSTERID ("-clusterid"),
049 GENCLUSTERID ("-genclusterid"),
050 REGULAR ("-regular"),
051 BACKUP ("-backup"),
052 CHECKPOINT("-checkpoint"),
053 UPGRADE ("-upgrade"),
054 ROLLBACK("-rollback"),
055 FINALIZE("-finalize"),
056 IMPORT ("-importCheckpoint"),
057 BOOTSTRAPSTANDBY("-bootstrapStandby"),
058 INITIALIZESHAREDEDITS("-initializeSharedEdits"),
059 RECOVER ("-recover"),
060 FORCE("-force"),
061 NONINTERACTIVE("-nonInteractive");
062
063 private String name = null;
064
065 // Used only with format and upgrade options
066 private String clusterId = null;
067
068 // Used only with format option
069 private boolean isForceFormat = false;
070 private boolean isInteractiveFormat = true;
071
072 // Used only with recovery option
073 private int force = 0;
074
075 private StartupOption(String arg) {this.name = arg;}
076 public String getName() {return name;}
077 public NamenodeRole toNodeRole() {
078 switch(this) {
079 case BACKUP:
080 return NamenodeRole.BACKUP;
081 case CHECKPOINT:
082 return NamenodeRole.CHECKPOINT;
083 default:
084 return NamenodeRole.NAMENODE;
085 }
086 }
087
088 public void setClusterId(String cid) {
089 clusterId = cid;
090 }
091
092 public String getClusterId() {
093 return clusterId;
094 }
095
096 public MetaRecoveryContext createRecoveryContext() {
097 if (!name.equals(RECOVER.name))
098 return null;
099 return new MetaRecoveryContext(force);
100 }
101
102 public void setForce(int force) {
103 this.force = force;
104 }
105
106 public int getForce() {
107 return this.force;
108 }
109
110 public boolean getForceFormat() {
111 return isForceFormat;
112 }
113
114 public void setForceFormat(boolean force) {
115 isForceFormat = force;
116 }
117
118 public boolean getInteractiveFormat() {
119 return isInteractiveFormat;
120 }
121
122 public void setInteractiveFormat(boolean interactive) {
123 isInteractiveFormat = interactive;
124 }
125 }
126
127 // Timeouts for communicating with DataNode for streaming writes/reads
128 public static int READ_TIMEOUT = 60 * 1000;
129 public static int READ_TIMEOUT_EXTENSION = 5 * 1000;
130 public static int WRITE_TIMEOUT = 8 * 60 * 1000;
131 public static int WRITE_TIMEOUT_EXTENSION = 5 * 1000; //for write pipeline
132
133 /**
134 * Defines the NameNode role.
135 */
136 static public enum NamenodeRole {
137 NAMENODE ("NameNode"),
138 BACKUP ("Backup Node"),
139 CHECKPOINT("Checkpoint Node");
140
141 private String description = null;
142 private NamenodeRole(String arg) {this.description = arg;}
143
144 public String toString() {
145 return description;
146 }
147 }
148
149 /**
150 * Block replica states, which it can go through while being constructed.
151 */
152 static public enum ReplicaState {
153 /** Replica is finalized. The state when replica is not modified. */
154 FINALIZED(0),
155 /** Replica is being written to. */
156 RBW(1),
157 /** Replica is waiting to be recovered. */
158 RWR(2),
159 /** Replica is under recovery. */
160 RUR(3),
161 /** Temporary replica: created for replication and relocation only. */
162 TEMPORARY(4);
163
164 private int value;
165
166 private ReplicaState(int v) {
167 value = v;
168 }
169
170 public int getValue() {
171 return value;
172 }
173
174 public static ReplicaState getState(int v) {
175 return ReplicaState.values()[v];
176 }
177
178 /** Read from in */
179 public static ReplicaState read(DataInput in) throws IOException {
180 return values()[in.readByte()];
181 }
182
183 /** Write to out */
184 public void write(DataOutput out) throws IOException {
185 out.writeByte(ordinal());
186 }
187 }
188
189 /**
190 * States, which a block can go through while it is under construction.
191 */
192 static public enum BlockUCState {
193 /**
194 * Block construction completed.<br>
195 * The block has at least one {@link ReplicaState#FINALIZED} replica,
196 * and is not going to be modified.
197 */
198 COMPLETE,
199 /**
200 * The block is under construction.<br>
201 * It has been recently allocated for write or append.
202 */
203 UNDER_CONSTRUCTION,
204 /**
205 * The block is under recovery.<br>
206 * When a file lease expires its last block may not be {@link #COMPLETE}
207 * and needs to go through a recovery procedure,
208 * which synchronizes the existing replicas contents.
209 */
210 UNDER_RECOVERY,
211 /**
212 * The block is committed.<br>
213 * The client reported that all bytes are written to data-nodes
214 * with the given generation stamp and block length, but no
215 * {@link ReplicaState#FINALIZED}
216 * replicas has yet been reported by data-nodes themselves.
217 */
218 COMMITTED;
219 }
220
221 public static final String NAMENODE_LEASE_HOLDER = "HDFS_NameNode";
222 public static final long NAMENODE_LEASE_RECHECK_INTERVAL = 2000;
223 }
224