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1   /**
2    * Copyright 2010 The Apache Software Foundation
3    *
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *     http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing, software
15   * distributed under the License is distributed on an "AS IS" BASIS,
16   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17   * See the License for the specific language governing permissions and
18   * limitations under the License.
19   */
20  package org.apache.hadoop.hbase.mapreduce.replication;
21  
22  import java.io.IOException;
23  
24  import org.apache.commons.logging.Log;
25  import org.apache.commons.logging.LogFactory;
26  import org.apache.hadoop.conf.Configuration;
27  import org.apache.hadoop.hbase.HBaseConfiguration;
28  import org.apache.hadoop.hbase.HConstants;
29  import org.apache.hadoop.hbase.KeyValue;
30  import org.apache.hadoop.hbase.client.HConnection;
31  import org.apache.hadoop.hbase.client.HConnectionManager;
32  import org.apache.hadoop.hbase.client.HConnectionManager.HConnectable;
33  import org.apache.hadoop.hbase.client.HTable;
34  import org.apache.hadoop.hbase.client.Put;
35  import org.apache.hadoop.hbase.client.Result;
36  import org.apache.hadoop.hbase.client.ResultScanner;
37  import org.apache.hadoop.hbase.client.Scan;
38  import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
39  import org.apache.hadoop.hbase.mapreduce.TableInputFormat;
40  import org.apache.hadoop.hbase.mapreduce.TableMapReduceUtil;
41  import org.apache.hadoop.hbase.mapreduce.TableMapper;
42  import org.apache.hadoop.hbase.replication.ReplicationPeer;
43  import org.apache.hadoop.hbase.replication.ReplicationZookeeper;
44  import org.apache.hadoop.hbase.util.Bytes;
45  import org.apache.hadoop.mapreduce.Job;
46  import org.apache.hadoop.mapreduce.lib.output.NullOutputFormat;
47  import org.apache.zookeeper.KeeperException;
48  
49  /**
50   * This map-only job compares the data from a local table with a remote one.
51   * Every cell is compared and must have exactly the same keys (even timestamp)
52   * as well as same value. It is possible to restrict the job by time range and
53   * families. The peer id that's provided must match the one given when the
54   * replication stream was setup.
55   * <p>
56   * Two counters are provided, Verifier.Counters.GOODROWS and BADROWS. The reason
57   * for a why a row is different is shown in the map's log.
58   */
59  public class VerifyReplication {
60  
61    private static final Log LOG =
62        LogFactory.getLog(VerifyReplication.class);
63  
64    public final static String NAME = "verifyrep";
65    static long startTime = 0;
66    static long endTime = 0;
67    static String tableName = null;
68    static String families = null;
69    static String peerId = null;
70  
71    /**
72     * Map-only comparator for 2 tables
73     */
74    public static class Verifier
75        extends TableMapper<ImmutableBytesWritable, Put> {
76  
77      public static enum Counters {GOODROWS, BADROWS}
78  
79      private ResultScanner replicatedScanner;
80  
81      /**
82       * Map method that compares every scanned row with the equivalent from
83       * a distant cluster.
84       * @param row  The current table row key.
85       * @param value  The columns.
86       * @param context  The current context.
87       * @throws IOException When something is broken with the data.
88       */
89      @Override
90      public void map(ImmutableBytesWritable row, final Result value,
91                      Context context)
92          throws IOException {
93        if (replicatedScanner == null) {
94          Configuration conf = context.getConfiguration();
95          final Scan scan = new Scan();
96          scan.setCaching(conf.getInt(TableInputFormat.SCAN_CACHEDROWS, 1));
97          long startTime = conf.getLong(NAME + ".startTime", 0);
98          long endTime = conf.getLong(NAME + ".endTime", 0);
99          String families = conf.get(NAME + ".families", null);
100         if(families != null) {
101           String[] fams = families.split(",");
102           for(String fam : fams) {
103             scan.addFamily(Bytes.toBytes(fam));
104           }
105         }
106         if (startTime != 0) {
107           scan.setTimeRange(startTime,
108               endTime == 0 ? HConstants.LATEST_TIMESTAMP : endTime);
109         }
110         HConnectionManager.execute(new HConnectable<Void>(conf) {
111           @Override
112           public Void connect(HConnection conn) throws IOException {
113             try {
114               ReplicationZookeeper zk = new ReplicationZookeeper(conn, conf,
115                   conn.getZooKeeperWatcher());
116               ReplicationPeer peer = zk.getPeer(conf.get(NAME+".peerId"));
117               HTable replicatedTable = new HTable(peer.getConfiguration(),
118                   conf.get(NAME+".tableName"));
119               scan.setStartRow(value.getRow());
120               replicatedScanner = replicatedTable.getScanner(scan);
121             } catch (KeeperException e) {
122               throw new IOException("Got a ZK exception", e);
123             }
124             return null;
125           }
126         });
127       }
128       Result res = replicatedScanner.next();
129       try {
130         Result.compareResults(value, res);
131         context.getCounter(Counters.GOODROWS).increment(1);
132       } catch (Exception e) {
133         LOG.warn("Bad row", e);
134         context.getCounter(Counters.BADROWS).increment(1);
135       }
136     }
137 
138     protected void cleanup(Context context) {
139       if (replicatedScanner != null) {
140         replicatedScanner.close();
141         replicatedScanner = null;
142       }
143     }
144   }
145 
146   /**
147    * Sets up the actual job.
148    *
149    * @param conf  The current configuration.
150    * @param args  The command line parameters.
151    * @return The newly created job.
152    * @throws java.io.IOException When setting up the job fails.
153    */
154   public static Job createSubmittableJob(Configuration conf, String[] args)
155   throws IOException {
156     if (!doCommandLine(args)) {
157       return null;
158     }
159     if (!conf.getBoolean(HConstants.REPLICATION_ENABLE_KEY, false)) {
160       throw new IOException("Replication needs to be enabled to verify it.");
161     }
162     HConnectionManager.execute(new HConnectable<Void>(conf) {
163       @Override
164       public Void connect(HConnection conn) throws IOException {
165         try {
166           ReplicationZookeeper zk = new ReplicationZookeeper(conn, conf,
167               conn.getZooKeeperWatcher());
168           // Just verifying it we can connect
169           ReplicationPeer peer = zk.getPeer(peerId);
170           if (peer == null) {
171             throw new IOException("Couldn't get access to the slave cluster," +
172                 "please see the log");
173           }
174         } catch (KeeperException ex) {
175           throw new IOException("Couldn't get access to the slave cluster" +
176               " because: ", ex);
177         }
178         return null;
179       }
180     });
181     conf.set(NAME+".peerId", peerId);
182     conf.set(NAME+".tableName", tableName);
183     conf.setLong(NAME+".startTime", startTime);
184     conf.setLong(NAME+".endTime", endTime);
185     if (families != null) {
186       conf.set(NAME+".families", families);
187     }
188     Job job = new Job(conf, NAME + "_" + tableName);
189     job.setJarByClass(VerifyReplication.class);
190 
191     Scan scan = new Scan();
192     if (startTime != 0) {
193       scan.setTimeRange(startTime,
194           endTime == 0 ? HConstants.LATEST_TIMESTAMP : endTime);
195     }
196     if(families != null) {
197       String[] fams = families.split(",");
198       for(String fam : fams) {
199         scan.addFamily(Bytes.toBytes(fam));
200       }
201     }
202     TableMapReduceUtil.initTableMapperJob(tableName, scan,
203         Verifier.class, null, null, job);
204     job.setOutputFormatClass(NullOutputFormat.class);
205     job.setNumReduceTasks(0);
206     return job;
207   }
208 
209   private static boolean doCommandLine(final String[] args) {
210     if (args.length < 2) {
211       printUsage(null);
212       return false;
213     }
214     try {
215       for (int i = 0; i < args.length; i++) {
216         String cmd = args[i];
217         if (cmd.equals("-h") || cmd.startsWith("--h")) {
218           printUsage(null);
219           return false;
220         }
221 
222         final String startTimeArgKey = "--starttime=";
223         if (cmd.startsWith(startTimeArgKey)) {
224           startTime = Long.parseLong(cmd.substring(startTimeArgKey.length()));
225           continue;
226         }
227 
228         final String endTimeArgKey = "--endtime=";
229         if (cmd.startsWith(endTimeArgKey)) {
230           endTime = Long.parseLong(cmd.substring(endTimeArgKey.length()));
231           continue;
232         }
233 
234         final String familiesArgKey = "--families=";
235         if (cmd.startsWith(familiesArgKey)) {
236           families = cmd.substring(familiesArgKey.length());
237           continue;
238         }
239 
240         if (i == args.length-2) {
241           peerId = cmd;
242         }
243 
244         if (i == args.length-1) {
245           tableName = cmd;
246         }
247       }
248     } catch (Exception e) {
249       e.printStackTrace();
250       printUsage("Can't start because " + e.getMessage());
251       return false;
252     }
253     return true;
254   }
255 
256   /*
257    * @param errorMsg Error message.  Can be null.
258    */
259   private static void printUsage(final String errorMsg) {
260     if (errorMsg != null && errorMsg.length() > 0) {
261       System.err.println("ERROR: " + errorMsg);
262     }
263     System.err.println("Usage: verifyrep [--starttime=X]" +
264         " [--stoptime=Y] [--families=A] <peerid> <tablename>");
265     System.err.println();
266     System.err.println("Options:");
267     System.err.println(" starttime    beginning of the time range");
268     System.err.println("              without endtime means from starttime to forever");
269     System.err.println(" stoptime     end of the time range");
270     System.err.println(" families     comma-separated list of families to copy");
271     System.err.println();
272     System.err.println("Args:");
273     System.err.println(" peerid       Id of the peer used for verification, must match the one given for replication");
274     System.err.println(" tablename    Name of the table to verify");
275     System.err.println();
276     System.err.println("Examples:");
277     System.err.println(" To verify the data replicated from TestTable for a 1 hour window with peer #5 ");
278     System.err.println(" $ bin/hbase " +
279         "org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication" +
280         " --starttime=1265875194289 --stoptime=1265878794289 5 TestTable ");
281   }
282 
283   /**
284    * Main entry point.
285    *
286    * @param args  The command line parameters.
287    * @throws Exception When running the job fails.
288    */
289   public static void main(String[] args) throws Exception {
290     Configuration conf = HBaseConfiguration.create();
291     Job job = createSubmittableJob(conf, args);
292     if (job != null) {
293       System.exit(job.waitForCompletion(true) ? 0 : 1);
294     }
295   }
296 }