hbase-client/src/main/java/org/apache/hadoop/hbase/exceptions/RegionMovedException.java

   1 /**
   2  * Licensed to the Apache Software Foundation (ASF) under one
   3  * or more contributor license agreements.  See the NOTICE file
   4  * distributed with this work for additional information
   5  * regarding copyright ownership.  The ASF licenses this file
   6  * to you under the Apache License, Version 2.0 (the
   7  * "License"); you may not use this file except in compliance
   8  * with the License.  You may obtain a copy of the License at
   9  *
  10  *     http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * Unless required by applicable law or agreed to in writing, software
  13  * distributed under the License is distributed on an "AS IS" BASIS,
  14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  * See the License for the specific language governing permissions and
  16  * limitations under the License.
  17  */
  18 package org.apache.hadoop.hbase.exceptions;
  19
  20 import org.apache.hadoop.hbase.HConstants;
  21 import org.apache.hadoop.hbase.NotServingRegionException;
  22 import org.apache.hadoop.hbase.ServerName;
  23 import org.apache.yetus.audience.InterfaceAudience;
  24 import org.apache.yetus.audience.InterfaceStability;
  25 import org.slf4j.Logger;
  26 import org.slf4j.LoggerFactory;
  27
  28 /**
  29  * Subclass if the server knows the region is now on another server.
  30  * This allows the client to call the new region server without calling the master.
  31  */
  32 @InterfaceAudience.Private
  33 @InterfaceStability.Evolving
  34 public class RegionMovedException extends NotServingRegionException {
  35   private static final Logger LOG = LoggerFactory.getLogger(RegionMovedException.class);
  36   private static final long serialVersionUID = -7232903522310558396L;
  37
  38   private final String hostname;
  39   private final int port;
  40   private final long startCode;
  41   private final long locationSeqNum;
  42
  43   private static final String HOST_FIELD = "hostname=";
  44   private static final String PORT_FIELD = "port=";
  45   private static final String STARTCODE_FIELD = "startCode=";
  46   private static final String LOCATIONSEQNUM_FIELD = "locationSeqNum=";
  47
  48
  49   public RegionMovedException(ServerName serverName, long locationSeqNum) {
  50     this.hostname = serverName.getHostname();
  51     this.port = serverName.getPort();
  52     this.startCode = serverName.getStartcode();
  53     this.locationSeqNum = locationSeqNum;
  54   }
  55
  56   public String getHostname() {
  57     return hostname;
  58   }
  59
  60   public int getPort() {
  61     return port;
  62   }
  63
  64   public ServerName getServerName(){
  65     return ServerName.valueOf(hostname, port, startCode);
  66   }
  67
  68   public long getLocationSeqNum() {
  69     return locationSeqNum;
  70   }
  71
  72   /**
  73    * For hadoop.ipc internal call. Do NOT use.
  74    * We have to parse the hostname to recreate the exception.
  75    * The input is the one generated by {@link #getMessage()}
  76    */
  77   public RegionMovedException(String s) {
  78     int posHostname = s.indexOf(HOST_FIELD) + HOST_FIELD.length();
  79     int posPort = s.indexOf(PORT_FIELD) + PORT_FIELD.length();
  80     int posStartCode = s.indexOf(STARTCODE_FIELD) + STARTCODE_FIELD.length();
  81     int posSeqNum = s.indexOf(LOCATIONSEQNUM_FIELD) + LOCATIONSEQNUM_FIELD.length();
  82
  83     String tmpHostname = null;
  84     int tmpPort = -1;
  85     long tmpStartCode = -1;
  86     long tmpSeqNum = HConstants.NO_SEQNUM;
  87     try {
  88       // TODO: this whole thing is extremely brittle.
  89       tmpHostname = s.substring(posHostname, s.indexOf(' ', posHostname));
  90       tmpPort = Integer.parseInt(s.substring(posPort, s.indexOf(' ', posPort)));
  91       tmpStartCode =  Long.parseLong(s.substring(posStartCode, s.indexOf('.', posStartCode)));
  92       tmpSeqNum = Long.parseLong(s.substring(posSeqNum, s.indexOf('.', posSeqNum)));
  93     } catch (Exception ignored) {
  94       LOG.warn("Can't parse the hostname, port and startCode from this string: " +
  95           s + ", continuing");
  96     }
  97
  98     hostname = tmpHostname;
  99     port = tmpPort;
 100     startCode = tmpStartCode;
 101     locationSeqNum = tmpSeqNum;
 102   }
 103
 104   @Override
 105   public String getMessage() {
 106     // TODO: deserialization above depends on this. That is bad, but also means this
 107     // should be modified carefully.
 108     return "Region moved to: " + HOST_FIELD + hostname + " " + PORT_FIELD + port + " " +
 109         STARTCODE_FIELD + startCode + ". As of "  + LOCATIONSEQNUM_FIELD + locationSeqNum + ".";
 110   }
 111 }