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 */
018package org.apache.hadoop.hbase.mapred;
019
020import java.io.IOException;
021import org.apache.hadoop.fs.FileAlreadyExistsException;
022import org.apache.hadoop.fs.FileSystem;
023import org.apache.hadoop.hbase.TableName;
024import org.apache.hadoop.hbase.client.BufferedMutator;
025import org.apache.hadoop.hbase.client.Connection;
026import org.apache.hadoop.hbase.client.ConnectionFactory;
027import org.apache.hadoop.hbase.client.Put;
028import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
029import org.apache.hadoop.mapred.FileOutputFormat;
030import org.apache.hadoop.mapred.InvalidJobConfException;
031import org.apache.hadoop.mapred.JobConf;
032import org.apache.hadoop.mapred.RecordWriter;
033import org.apache.hadoop.mapred.Reporter;
034import org.apache.hadoop.util.Progressable;
035import org.apache.yetus.audience.InterfaceAudience;
036
037/**
038 * Convert Map/Reduce output and write it to an HBase table
039 */
040@InterfaceAudience.Public
041public class TableOutputFormat extends FileOutputFormat<ImmutableBytesWritable, Put> {
042
043  /** JobConf parameter that specifies the output table */
044  public static final String OUTPUT_TABLE = "hbase.mapred.outputtable";
045
046  /**
047   * Convert Reduce output (key, value) to (HStoreKey, KeyedDataArrayWritable) and write to an HBase
048   * table.
049   */
050  protected static class TableRecordWriter implements RecordWriter<ImmutableBytesWritable, Put> {
051    private BufferedMutator m_mutator;
052    private Connection conn;
053
054    /**
055     * Instantiate a TableRecordWriter with a BufferedMutator for batch writing.
056     */
057    public TableRecordWriter(JobConf job) throws IOException {
058      // expecting exactly one path
059      TableName tableName = TableName.valueOf(job.get(OUTPUT_TABLE));
060      try {
061        this.conn = ConnectionFactory.createConnection(job);
062        this.m_mutator = conn.getBufferedMutator(tableName);
063      } finally {
064        if (this.m_mutator == null) {
065          conn.close();
066          conn = null;
067        }
068      }
069    }
070
071    public void close(Reporter reporter) throws IOException {
072      try {
073        if (this.m_mutator != null) {
074          this.m_mutator.close();
075        }
076      } finally {
077        if (conn != null) {
078          this.conn.close();
079        }
080      }
081    }
082
083    public void write(ImmutableBytesWritable key, Put value) throws IOException {
084      m_mutator.mutate(new Put(value));
085    }
086  }
087
088  /**
089   * Creates a new record writer. Be aware that the baseline javadoc gives the impression that there
090   * is a single {@link RecordWriter} per job but in HBase, it is more natural if we give you a new
091   * RecordWriter per call of this method. You must close the returned RecordWriter when done.
092   * Failure to do so will drop writes.
093   * @param ignored Ignored filesystem
094   * @param job     Current JobConf
095   * @param name    Name of the job n * @return The newly created writer instance.
096   * @throws IOException When creating the writer fails.
097   */
098  @Override
099  public RecordWriter getRecordWriter(FileSystem ignored, JobConf job, String name,
100    Progressable progress) throws IOException {
101    // Clear write buffer on fail is true by default so no need to reset it.
102    return new TableRecordWriter(job);
103  }
104
105  @Override
106  public void checkOutputSpecs(FileSystem ignored, JobConf job)
107    throws FileAlreadyExistsException, InvalidJobConfException, IOException {
108    String tableName = job.get(OUTPUT_TABLE);
109    if (tableName == null) {
110      throw new IOException("Must specify table name");
111    }
112  }
113}