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1   /**
2   *
3   * Licensed to the Apache Software Foundation (ASF) under one
4   * or more contributor license agreements.  See the NOTICE file
5   * distributed with this work for additional information
6   * regarding copyright ownership.  The ASF licenses this file
7   * to you under the Apache License, Version 2.0 (the
8   * "License"); you may not use this file except in compliance
9   * with the License.  You may obtain a copy of the License at
10  *
11  *     http://www.apache.org/licenses/LICENSE-2.0
12  *
13  * Unless required by applicable law or agreed to in writing, software
14  * distributed under the License is distributed on an "AS IS" BASIS,
15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16  * See the License for the specific language governing permissions and
17  * limitations under the License.
18  */
19  package org.apache.hadoop.hbase.mapreduce;
20  
21  import java.io.IOException;
22  
23  import org.apache.commons.logging.Log;
24  import org.apache.commons.logging.LogFactory;
25  import org.apache.hadoop.hbase.classification.InterfaceAudience;
26  import org.apache.hadoop.hbase.classification.InterfaceStability;
27  import org.apache.hadoop.conf.Configuration;
28  import org.apache.hadoop.conf.Configured;
29  import org.apache.hadoop.fs.Path;
30  import org.apache.hadoop.hbase.HBaseConfiguration;
31  import org.apache.hadoop.hbase.client.Result;
32  import org.apache.hadoop.hbase.client.Scan;
33  import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
34  import org.apache.hadoop.hbase.filter.Filter;
35  import org.apache.hadoop.hbase.filter.IncompatibleFilterException;
36  import org.apache.hadoop.hbase.filter.PrefixFilter;
37  import org.apache.hadoop.hbase.filter.RegexStringComparator;
38  import org.apache.hadoop.hbase.filter.RowFilter;
39  import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
40  import org.apache.hadoop.hbase.util.Bytes;
41  import org.apache.hadoop.mapreduce.Job;
42  import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
43  import org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat;
44  import org.apache.hadoop.util.Tool;
45  import org.apache.hadoop.util.ToolRunner;
46  
47  /**
48  * Export an HBase table.
49  * Writes content to sequence files up in HDFS.  Use {@link Import} to read it
50  * back in again.
51  */
52  @InterfaceAudience.Public
53  @InterfaceStability.Stable
54  public class Export extends Configured implements Tool {
55    private static final Log LOG = LogFactory.getLog(Export.class);
56    final static String NAME = "export";
57    final static String RAW_SCAN = "hbase.mapreduce.include.deleted.rows";
58    final static String EXPORT_BATCHING = "hbase.export.scanner.batch";
59  
60    private final static String JOB_NAME_CONF_KEY = "mapreduce.job.name";
61  
62    /**
63     * Sets up the actual job.
64     *
65     * @param conf  The current configuration.
66     * @param args  The command line parameters.
67     * @return The newly created job.
68     * @throws IOException When setting up the job fails.
69     */
70    public static Job createSubmittableJob(Configuration conf, String[] args)
71    throws IOException {
72      String tableName = args[0];
73      Path outputDir = new Path(args[1]);
74      Job job = Job.getInstance(conf, conf.get(JOB_NAME_CONF_KEY, NAME + "_" + tableName));
75      job.setJobName(NAME + "_" + tableName);
76      job.setJarByClass(Export.class);
77      // Set optional scan parameters
78      Scan s = getConfiguredScanForJob(conf, args);
79      IdentityTableMapper.initJob(tableName, s, IdentityTableMapper.class, job);
80      // No reducers.  Just write straight to output files.
81      job.setNumReduceTasks(0);
82      job.setOutputFormatClass(SequenceFileOutputFormat.class);
83      job.setOutputKeyClass(ImmutableBytesWritable.class);
84      job.setOutputValueClass(Result.class);
85      FileOutputFormat.setOutputPath(job, outputDir); // job conf doesn't contain the conf so doesn't have a default fs.
86      return job;
87    }
88  
89    private static Scan getConfiguredScanForJob(Configuration conf, String[] args) throws IOException {
90      Scan s = new Scan();
91      // Optional arguments.
92      // Set Scan Versions
93      int versions = args.length > 2? Integer.parseInt(args[2]): 1;
94      s.setMaxVersions(versions);
95      // Set Scan Range
96      long startTime = args.length > 3? Long.parseLong(args[3]): 0L;
97      long endTime = args.length > 4? Long.parseLong(args[4]): Long.MAX_VALUE;
98      s.setTimeRange(startTime, endTime);
99      // Set cache blocks
100     s.setCacheBlocks(false);
101     // set Start and Stop row
102     if (conf.get(TableInputFormat.SCAN_ROW_START) != null) {
103       s.setStartRow(Bytes.toBytesBinary(conf.get(TableInputFormat.SCAN_ROW_START)));
104     }
105     if (conf.get(TableInputFormat.SCAN_ROW_STOP) != null) {
106       s.setStopRow(Bytes.toBytesBinary(conf.get(TableInputFormat.SCAN_ROW_STOP)));
107     }
108     // Set Scan Column Family
109     boolean raw = Boolean.parseBoolean(conf.get(RAW_SCAN));
110     if (raw) {
111       s.setRaw(raw);
112     }
113     
114     if (conf.get(TableInputFormat.SCAN_COLUMN_FAMILY) != null) {
115       s.addFamily(Bytes.toBytes(conf.get(TableInputFormat.SCAN_COLUMN_FAMILY)));
116     }
117     // Set RowFilter or Prefix Filter if applicable.
118     Filter exportFilter = getExportFilter(args);
119     if (exportFilter!= null) {
120         LOG.info("Setting Scan Filter for Export.");
121       s.setFilter(exportFilter);
122     }
123 
124     int batching = conf.getInt(EXPORT_BATCHING, -1);
125     if (batching !=  -1){
126       try {
127         s.setBatch(batching);
128       } catch (IncompatibleFilterException e) {
129         LOG.error("Batching could not be set", e);
130       }
131     }
132     LOG.info("versions=" + versions + ", starttime=" + startTime +
133       ", endtime=" + endTime + ", keepDeletedCells=" + raw);
134     return s;
135   }
136 
137   private static Filter getExportFilter(String[] args) {
138     Filter exportFilter = null;
139     String filterCriteria = (args.length > 5) ? args[5]: null;
140     if (filterCriteria == null) return null;
141     if (filterCriteria.startsWith("^")) {
142       String regexPattern = filterCriteria.substring(1, filterCriteria.length());
143       exportFilter = new RowFilter(CompareOp.EQUAL, new RegexStringComparator(regexPattern));
144     } else {
145       exportFilter = new PrefixFilter(Bytes.toBytesBinary(filterCriteria));
146     }
147     return exportFilter;
148   }
149 
150   /*
151    * @param errorMsg Error message.  Can be null.
152    */
153   private static void usage(final String errorMsg) {
154     if (errorMsg != null && errorMsg.length() > 0) {
155       System.err.println("ERROR: " + errorMsg);
156     }
157     System.err.println("Usage: Export [-D <property=value>]* <tablename> <outputdir> [<versions> " +
158       "[<starttime> [<endtime>]] [^[regex pattern] or [Prefix] to filter]]\n");
159     System.err.println("  Note: -D properties will be applied to the conf used. ");
160     System.err.println("  For example: ");
161     System.err.println("   -D mapreduce.output.fileoutputformat.compress=true");
162     System.err.println("   -D mapreduce.output.fileoutputformat.compress.codec=org.apache.hadoop.io.compress.GzipCodec");
163     System.err.println("   -D mapreduce.output.fileoutputformat.compress.type=BLOCK");
164     System.err.println("  Additionally, the following SCAN properties can be specified");
165     System.err.println("  to control/limit what is exported..");
166     System.err.println("   -D " + TableInputFormat.SCAN_COLUMN_FAMILY + "=<familyName>");
167     System.err.println("   -D " + RAW_SCAN + "=true");
168     System.err.println("   -D " + TableInputFormat.SCAN_ROW_START + "=<ROWSTART>");
169     System.err.println("   -D " + TableInputFormat.SCAN_ROW_STOP + "=<ROWSTOP>");
170     System.err.println("   -D " + JOB_NAME_CONF_KEY
171         + "=jobName - use the specified mapreduce job name for the export");
172     System.err.println("For performance consider the following properties:\n"
173         + "   -Dhbase.client.scanner.caching=100\n"
174         + "   -Dmapreduce.map.speculative=false\n"
175         + "   -Dmapreduce.reduce.speculative=false");
176     System.err.println("For tables with very wide rows consider setting the batch size as below:\n"
177         + "   -D" + EXPORT_BATCHING + "=10");
178   }
179 
180 
181   @Override
182   public int run(String[] args) throws Exception {
183     if (args.length < 2) {
184       usage("Wrong number of arguments: " + args.length);
185       return -1;
186     }
187     Job job = createSubmittableJob(getConf(), args);
188     return (job.waitForCompletion(true) ? 0 : 1);
189   }
190 
191   /**
192    * Main entry point.
193    * @param args The command line parameters.
194    * @throws Exception When running the job fails.
195    */
196   public static void main(String[] args) throws Exception {
197     int errCode = ToolRunner.run(HBaseConfiguration.create(), new Export(), args);
198     System.exit(errCode);
199   }
200 }