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<pre><span class="sourceLineNo">001</span>/**<a name="line.1"></a>
<span class="sourceLineNo">002</span> *<a name="line.2"></a>
<span class="sourceLineNo">003</span> * Licensed to the Apache Software Foundation (ASF) under one<a name="line.3"></a>
<span class="sourceLineNo">004</span> * or more contributor license agreements. See the NOTICE file<a name="line.4"></a>
<span class="sourceLineNo">005</span> * distributed with this work for additional information<a name="line.5"></a>
<span class="sourceLineNo">006</span> * regarding copyright ownership. The ASF licenses this file<a name="line.6"></a>
<span class="sourceLineNo">007</span> * to you under the Apache License, Version 2.0 (the<a name="line.7"></a>
<span class="sourceLineNo">008</span> * "License"); you may not use this file except in compliance<a name="line.8"></a>
<span class="sourceLineNo">009</span> * with the License. You may obtain a copy of the License at<a name="line.9"></a>
<span class="sourceLineNo">010</span> *<a name="line.10"></a>
<span class="sourceLineNo">011</span> * http://www.apache.org/licenses/LICENSE-2.0<a name="line.11"></a>
<span class="sourceLineNo">012</span> *<a name="line.12"></a>
<span class="sourceLineNo">013</span> * Unless required by applicable law or agreed to in writing, software<a name="line.13"></a>
<span class="sourceLineNo">014</span> * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.14"></a>
<span class="sourceLineNo">015</span> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.15"></a>
<span class="sourceLineNo">016</span> * See the License for the specific language governing permissions and<a name="line.16"></a>
<span class="sourceLineNo">017</span> * limitations under the License.<a name="line.17"></a>
<span class="sourceLineNo">018</span> */<a name="line.18"></a>
<span class="sourceLineNo">019</span>package org.apache.hadoop.hbase.mapreduce;<a name="line.19"></a>
<span class="sourceLineNo">020</span><a name="line.20"></a>
<span class="sourceLineNo">021</span>import java.io.IOException;<a name="line.21"></a>
<span class="sourceLineNo">022</span>import org.apache.yetus.audience.InterfaceAudience;<a name="line.22"></a>
<span class="sourceLineNo">023</span>import org.slf4j.Logger;<a name="line.23"></a>
<span class="sourceLineNo">024</span>import org.slf4j.LoggerFactory;<a name="line.24"></a>
<span class="sourceLineNo">025</span>import org.apache.hadoop.conf.Configurable;<a name="line.25"></a>
<span class="sourceLineNo">026</span>import org.apache.hadoop.conf.Configuration;<a name="line.26"></a>
<span class="sourceLineNo">027</span>import org.apache.hadoop.hbase.HBaseConfiguration;<a name="line.27"></a>
<span class="sourceLineNo">028</span>import org.apache.hadoop.hbase.TableName;<a name="line.28"></a>
<span class="sourceLineNo">029</span>import org.apache.hadoop.hbase.client.Connection;<a name="line.29"></a>
<span class="sourceLineNo">030</span>import org.apache.hadoop.hbase.client.ConnectionFactory;<a name="line.30"></a>
<span class="sourceLineNo">031</span>import org.apache.hadoop.hbase.client.RegionLocator;<a name="line.31"></a>
<span class="sourceLineNo">032</span>import org.apache.hadoop.hbase.io.ImmutableBytesWritable;<a name="line.32"></a>
<span class="sourceLineNo">033</span>import org.apache.hadoop.hbase.mapred.TableOutputFormat;<a name="line.33"></a>
<span class="sourceLineNo">034</span>import org.apache.hadoop.hbase.util.Bytes;<a name="line.34"></a>
<span class="sourceLineNo">035</span>import org.apache.hadoop.mapreduce.Partitioner;<a name="line.35"></a>
<span class="sourceLineNo">036</span><a name="line.36"></a>
<span class="sourceLineNo">037</span>/**<a name="line.37"></a>
<span class="sourceLineNo">038</span> * This is used to partition the output keys into groups of keys.<a name="line.38"></a>
<span class="sourceLineNo">039</span> * Keys are grouped according to the regions that currently exist<a name="line.39"></a>
<span class="sourceLineNo">040</span> * so that each reducer fills a single region so load is distributed.<a name="line.40"></a>
<span class="sourceLineNo">041</span> *<a name="line.41"></a>
<span class="sourceLineNo">042</span> * &lt;p&gt;This class is not suitable as partitioner creating hfiles<a name="line.42"></a>
<span class="sourceLineNo">043</span> * for incremental bulk loads as region spread will likely change between time of<a name="line.43"></a>
<span class="sourceLineNo">044</span> * hfile creation and load time. See {@link org.apache.hadoop.hbase.tool.BulkLoadHFiles}<a name="line.44"></a>
<span class="sourceLineNo">045</span> * and &lt;a href="http://hbase.apache.org/book.html#arch.bulk.load"&gt;Bulk Load&lt;/a&gt;.&lt;/p&gt;<a name="line.45"></a>
<span class="sourceLineNo">046</span> *<a name="line.46"></a>
<span class="sourceLineNo">047</span> * @param &lt;KEY&gt; The type of the key.<a name="line.47"></a>
<span class="sourceLineNo">048</span> * @param &lt;VALUE&gt; The type of the value.<a name="line.48"></a>
<span class="sourceLineNo">049</span> */<a name="line.49"></a>
<span class="sourceLineNo">050</span>@InterfaceAudience.Public<a name="line.50"></a>
<span class="sourceLineNo">051</span>public class HRegionPartitioner&lt;KEY, VALUE&gt;<a name="line.51"></a>
<span class="sourceLineNo">052</span>extends Partitioner&lt;ImmutableBytesWritable, VALUE&gt;<a name="line.52"></a>
<span class="sourceLineNo">053</span>implements Configurable {<a name="line.53"></a>
<span class="sourceLineNo">054</span><a name="line.54"></a>
<span class="sourceLineNo">055</span> private static final Logger LOG = LoggerFactory.getLogger(HRegionPartitioner.class);<a name="line.55"></a>
<span class="sourceLineNo">056</span> private Configuration conf = null;<a name="line.56"></a>
<span class="sourceLineNo">057</span> // Connection and locator are not cleaned up; they just die when partitioner is done.<a name="line.57"></a>
<span class="sourceLineNo">058</span> private Connection connection;<a name="line.58"></a>
<span class="sourceLineNo">059</span> private RegionLocator locator;<a name="line.59"></a>
<span class="sourceLineNo">060</span> private byte[][] startKeys;<a name="line.60"></a>
<span class="sourceLineNo">061</span><a name="line.61"></a>
<span class="sourceLineNo">062</span> /**<a name="line.62"></a>
<span class="sourceLineNo">063</span> * Gets the partition number for a given key (hence record) given the total<a name="line.63"></a>
<span class="sourceLineNo">064</span> * number of partitions i.e. number of reduce-tasks for the job.<a name="line.64"></a>
<span class="sourceLineNo">065</span> *<a name="line.65"></a>
<span class="sourceLineNo">066</span> * &lt;p&gt;Typically a hash function on a all or a subset of the key.&lt;/p&gt;<a name="line.66"></a>
<span class="sourceLineNo">067</span> *<a name="line.67"></a>
<span class="sourceLineNo">068</span> * @param key The key to be partitioned.<a name="line.68"></a>
<span class="sourceLineNo">069</span> * @param value The entry value.<a name="line.69"></a>
<span class="sourceLineNo">070</span> * @param numPartitions The total number of partitions.<a name="line.70"></a>
<span class="sourceLineNo">071</span> * @return The partition number for the &lt;code&gt;key&lt;/code&gt;.<a name="line.71"></a>
<span class="sourceLineNo">072</span> * @see org.apache.hadoop.mapreduce.Partitioner#getPartition(<a name="line.72"></a>
<span class="sourceLineNo">073</span> * java.lang.Object, java.lang.Object, int)<a name="line.73"></a>
<span class="sourceLineNo">074</span> */<a name="line.74"></a>
<span class="sourceLineNo">075</span> @Override<a name="line.75"></a>
<span class="sourceLineNo">076</span> public int getPartition(ImmutableBytesWritable key,<a name="line.76"></a>
<span class="sourceLineNo">077</span> VALUE value, int numPartitions) {<a name="line.77"></a>
<span class="sourceLineNo">078</span> byte[] region = null;<a name="line.78"></a>
<span class="sourceLineNo">079</span> // Only one region return 0<a name="line.79"></a>
<span class="sourceLineNo">080</span> if (this.startKeys.length == 1){<a name="line.80"></a>
<span class="sourceLineNo">081</span> return 0;<a name="line.81"></a>
<span class="sourceLineNo">082</span> }<a name="line.82"></a>
<span class="sourceLineNo">083</span> try {<a name="line.83"></a>
<span class="sourceLineNo">084</span> // Not sure if this is cached after a split so we could have problems<a name="line.84"></a>
<span class="sourceLineNo">085</span> // here if a region splits while mapping<a name="line.85"></a>
<span class="sourceLineNo">086</span> region = this.locator.getRegionLocation(key.get()).getRegion().getStartKey();<a name="line.86"></a>
<span class="sourceLineNo">087</span> } catch (IOException e) {<a name="line.87"></a>
<span class="sourceLineNo">088</span> LOG.error(e.toString(), e);<a name="line.88"></a>
<span class="sourceLineNo">089</span> }<a name="line.89"></a>
<span class="sourceLineNo">090</span> for (int i = 0; i &lt; this.startKeys.length; i++){<a name="line.90"></a>
<span class="sourceLineNo">091</span> if (Bytes.compareTo(region, this.startKeys[i]) == 0 ){<a name="line.91"></a>
<span class="sourceLineNo">092</span> if (i &gt;= numPartitions-1){<a name="line.92"></a>
<span class="sourceLineNo">093</span> // cover if we have less reduces then regions.<a name="line.93"></a>
<span class="sourceLineNo">094</span> return (Integer.toString(i).hashCode()<a name="line.94"></a>
<span class="sourceLineNo">095</span> &amp; Integer.MAX_VALUE) % numPartitions;<a name="line.95"></a>
<span class="sourceLineNo">096</span> }<a name="line.96"></a>
<span class="sourceLineNo">097</span> return i;<a name="line.97"></a>
<span class="sourceLineNo">098</span> }<a name="line.98"></a>
<span class="sourceLineNo">099</span> }<a name="line.99"></a>
<span class="sourceLineNo">100</span> // if above fails to find start key that match we need to return something<a name="line.100"></a>
<span class="sourceLineNo">101</span> return 0;<a name="line.101"></a>
<span class="sourceLineNo">102</span> }<a name="line.102"></a>
<span class="sourceLineNo">103</span><a name="line.103"></a>
<span class="sourceLineNo">104</span> /**<a name="line.104"></a>
<span class="sourceLineNo">105</span> * Returns the current configuration.<a name="line.105"></a>
<span class="sourceLineNo">106</span> *<a name="line.106"></a>
<span class="sourceLineNo">107</span> * @return The current configuration.<a name="line.107"></a>
<span class="sourceLineNo">108</span> * @see org.apache.hadoop.conf.Configurable#getConf()<a name="line.108"></a>
<span class="sourceLineNo">109</span> */<a name="line.109"></a>
<span class="sourceLineNo">110</span> @Override<a name="line.110"></a>
<span class="sourceLineNo">111</span> public Configuration getConf() {<a name="line.111"></a>
<span class="sourceLineNo">112</span> return conf;<a name="line.112"></a>
<span class="sourceLineNo">113</span> }<a name="line.113"></a>
<span class="sourceLineNo">114</span><a name="line.114"></a>
<span class="sourceLineNo">115</span> /**<a name="line.115"></a>
<span class="sourceLineNo">116</span> * Sets the configuration. This is used to determine the start keys for the<a name="line.116"></a>
<span class="sourceLineNo">117</span> * given table.<a name="line.117"></a>
<span class="sourceLineNo">118</span> *<a name="line.118"></a>
<span class="sourceLineNo">119</span> * @param configuration The configuration to set.<a name="line.119"></a>
<span class="sourceLineNo">120</span> * @see org.apache.hadoop.conf.Configurable#setConf(<a name="line.120"></a>
<span class="sourceLineNo">121</span> * org.apache.hadoop.conf.Configuration)<a name="line.121"></a>
<span class="sourceLineNo">122</span> */<a name="line.122"></a>
<span class="sourceLineNo">123</span> @Override<a name="line.123"></a>
<span class="sourceLineNo">124</span> public void setConf(Configuration configuration) {<a name="line.124"></a>
<span class="sourceLineNo">125</span> this.conf = HBaseConfiguration.create(configuration);<a name="line.125"></a>
<span class="sourceLineNo">126</span> try {<a name="line.126"></a>
<span class="sourceLineNo">127</span> this.connection = ConnectionFactory.createConnection(HBaseConfiguration.create(conf));<a name="line.127"></a>
<span class="sourceLineNo">128</span> TableName tableName = TableName.valueOf(conf.get(TableOutputFormat.OUTPUT_TABLE));<a name="line.128"></a>
<span class="sourceLineNo">129</span> this.locator = this.connection.getRegionLocator(tableName);<a name="line.129"></a>
<span class="sourceLineNo">130</span> } catch (IOException e) {<a name="line.130"></a>
<span class="sourceLineNo">131</span> LOG.error(e.toString(), e);<a name="line.131"></a>
<span class="sourceLineNo">132</span> }<a name="line.132"></a>
<span class="sourceLineNo">133</span> try {<a name="line.133"></a>
<span class="sourceLineNo">134</span> this.startKeys = this.locator.getStartKeys();<a name="line.134"></a>
<span class="sourceLineNo">135</span> } catch (IOException e) {<a name="line.135"></a>
<span class="sourceLineNo">136</span> LOG.error(e.toString(), e);<a name="line.136"></a>
<span class="sourceLineNo">137</span> }<a name="line.137"></a>
<span class="sourceLineNo">138</span> }<a name="line.138"></a>
<span class="sourceLineNo">139</span>}<a name="line.139"></a>
</pre>
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