| /** |
| * Copyright 2009 The Apache Software Foundation |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.hadoop.hbase.mapreduce; |
| |
| import java.io.IOException; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.conf.Configurable; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.hbase.HConstants; |
| import org.apache.hadoop.hbase.client.Delete; |
| import org.apache.hadoop.hbase.client.HConnectionManager; |
| import org.apache.hadoop.hbase.client.HTable; |
| import org.apache.hadoop.hbase.client.Put; |
| import org.apache.hadoop.hbase.zookeeper.ZKUtil; |
| import org.apache.hadoop.io.Writable; |
| import org.apache.hadoop.mapreduce.JobContext; |
| import org.apache.hadoop.mapreduce.OutputCommitter; |
| import org.apache.hadoop.mapreduce.OutputFormat; |
| import org.apache.hadoop.mapreduce.RecordWriter; |
| import org.apache.hadoop.mapreduce.TaskAttemptContext; |
| |
| /** |
| * Convert Map/Reduce output and write it to an HBase table. The KEY is ignored |
| * while the output value <u>must</u> be either a {@link Put} or a |
| * {@link Delete} instance. |
| * |
| * @param <KEY> The type of the key. Ignored in this class. |
| */ |
| public class TableOutputFormat<KEY> extends OutputFormat<KEY, Writable> |
| implements Configurable { |
| |
| private final Log LOG = LogFactory.getLog(TableOutputFormat.class); |
| |
| /** Job parameter that specifies the output table. */ |
| public static final String OUTPUT_TABLE = "hbase.mapred.outputtable"; |
| |
| /** |
| * Optional job parameter to specify a peer cluster. |
| * Used specifying remote cluster when copying between hbase clusters (the |
| * source is picked up from <code>hbase-site.xml</code>). |
| * @see TableMapReduceUtil#initTableReducerJob(String, Class, org.apache.hadoop.mapreduce.Job, Class, String, String, String) |
| */ |
| public static final String QUORUM_ADDRESS = "hbase.mapred.output.quorum"; |
| |
| /** Optional specification of the rs class name of the peer cluster */ |
| public static final String |
| REGION_SERVER_CLASS = "hbase.mapred.output.rs.class"; |
| /** Optional specification of the rs impl name of the peer cluster */ |
| public static final String |
| REGION_SERVER_IMPL = "hbase.mapred.output.rs.impl"; |
| |
| /** The configuration. */ |
| private Configuration conf = null; |
| |
| private HTable table; |
| |
| /** |
| * Writes the reducer output to an HBase table. |
| * |
| * @param <KEY> The type of the key. |
| */ |
| protected static class TableRecordWriter<KEY> |
| extends RecordWriter<KEY, Writable> { |
| |
| /** The table to write to. */ |
| private HTable table; |
| |
| /** |
| * Instantiate a TableRecordWriter with the HBase HClient for writing. |
| * |
| * @param table The table to write to. |
| */ |
| public TableRecordWriter(HTable table) { |
| this.table = table; |
| } |
| |
| /** |
| * Closes the writer, in this case flush table commits. |
| * |
| * @param context The context. |
| * @throws IOException When closing the writer fails. |
| * @see org.apache.hadoop.mapreduce.RecordWriter#close(org.apache.hadoop.mapreduce.TaskAttemptContext) |
| */ |
| @Override |
| public void close(TaskAttemptContext context) |
| throws IOException { |
| table.flushCommits(); |
| // The following call will shutdown all connections to the cluster from |
| // this JVM. It will close out our zk session otherwise zk wil log |
| // expired sessions rather than closed ones. If any other HTable instance |
| // running in this JVM, this next call will cause it damage. Presumption |
| // is that the above this.table is only instance. |
| HConnectionManager.deleteAllConnections(true); |
| } |
| |
| /** |
| * Writes a key/value pair into the table. |
| * |
| * @param key The key. |
| * @param value The value. |
| * @throws IOException When writing fails. |
| * @see org.apache.hadoop.mapreduce.RecordWriter#write(java.lang.Object, java.lang.Object) |
| */ |
| @Override |
| public void write(KEY key, Writable value) |
| throws IOException { |
| if (value instanceof Put) this.table.put(new Put((Put)value)); |
| else if (value instanceof Delete) this.table.delete(new Delete((Delete)value)); |
| else throw new IOException("Pass a Delete or a Put"); |
| } |
| } |
| |
| /** |
| * Creates a new record writer. |
| * |
| * @param context The current task context. |
| * @return The newly created writer instance. |
| * @throws IOException When creating the writer fails. |
| * @throws InterruptedException When the jobs is cancelled. |
| * @see org.apache.hadoop.mapreduce.lib.output.FileOutputFormat#getRecordWriter(org.apache.hadoop.mapreduce.TaskAttemptContext) |
| */ |
| @Override |
| public RecordWriter<KEY, Writable> getRecordWriter( |
| TaskAttemptContext context) |
| throws IOException, InterruptedException { |
| return new TableRecordWriter<KEY>(this.table); |
| } |
| |
| /** |
| * Checks if the output target exists. |
| * |
| * @param context The current context. |
| * @throws IOException When the check fails. |
| * @throws InterruptedException When the job is aborted. |
| * @see org.apache.hadoop.mapreduce.OutputFormat#checkOutputSpecs(org.apache.hadoop.mapreduce.JobContext) |
| */ |
| @Override |
| public void checkOutputSpecs(JobContext context) throws IOException, |
| InterruptedException { |
| // TODO Check if the table exists? |
| |
| } |
| |
| /** |
| * Returns the output committer. |
| * |
| * @param context The current context. |
| * @return The committer. |
| * @throws IOException When creating the committer fails. |
| * @throws InterruptedException When the job is aborted. |
| * @see org.apache.hadoop.mapreduce.OutputFormat#getOutputCommitter(org.apache.hadoop.mapreduce.TaskAttemptContext) |
| */ |
| @Override |
| public OutputCommitter getOutputCommitter(TaskAttemptContext context) |
| throws IOException, InterruptedException { |
| return new TableOutputCommitter(); |
| } |
| |
| public Configuration getConf() { |
| return conf; |
| } |
| |
| @Override |
| public void setConf(Configuration conf) { |
| String tableName = conf.get(OUTPUT_TABLE); |
| String address = conf.get(QUORUM_ADDRESS); |
| String serverClass = conf.get(REGION_SERVER_CLASS); |
| String serverImpl = conf.get(REGION_SERVER_IMPL); |
| try { |
| if (address != null) { |
| ZKUtil.applyClusterKeyToConf(conf, address); |
| } |
| if (serverClass != null) { |
| conf.set(HConstants.REGION_SERVER_CLASS, serverClass); |
| conf.set(HConstants.REGION_SERVER_IMPL, serverImpl); |
| } |
| this.table = new HTable(conf, tableName); |
| table.setAutoFlush(false); |
| LOG.info("Created table instance for " + tableName); |
| } catch(IOException e) { |
| LOG.error(e); |
| } |
| } |
| } |