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From git-site-r...@apache.org
Subject [09/51] [partial] hbase-site git commit: Published site at 82d554e3783372cc6b05489452c815b57c06f6cd.
Date Tue, 20 Jun 2017 15:00:58 GMT
http://git-wip-us.apache.org/repos/asf/hbase-site/blob/a719cd00/devapidocs/src-html/org/apache/hadoop/hbase/master/balancer/StochasticLoadBalancer.ServerLocalityCostFunction.html
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diff --git a/devapidocs/src-html/org/apache/hadoop/hbase/master/balancer/StochasticLoadBalancer.ServerLocalityCostFunction.html b/devapidocs/src-html/org/apache/hadoop/hbase/master/balancer/StochasticLoadBalancer.ServerLocalityCostFunction.html
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+++ b/devapidocs/src-html/org/apache/hadoop/hbase/master/balancer/StochasticLoadBalancer.ServerLocalityCostFunction.html
@@ -0,0 +1,1779 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
+<html lang="en">
+<head>
+<title>Source code</title>
+<link rel="stylesheet" type="text/css" href="../../../../../../../stylesheet.css" title="Style">
+</head>
+<body>
+<div class="sourceContainer">
+<pre><span class="sourceLineNo">001</span>/**<a name="line.1"></a>
+<span class="sourceLineNo">002</span> * Licensed to the Apache Software Foundation (ASF) under one<a name="line.2"></a>
+<span class="sourceLineNo">003</span> * or more contributor license agreements.  See the NOTICE file<a name="line.3"></a>
+<span class="sourceLineNo">004</span> * distributed with this work for additional information<a name="line.4"></a>
+<span class="sourceLineNo">005</span> * regarding copyright ownership.  The ASF licenses this file<a name="line.5"></a>
+<span class="sourceLineNo">006</span> * to you under the Apache License, Version 2.0 (the<a name="line.6"></a>
+<span class="sourceLineNo">007</span> * "License"); you may not use this file except in compliance<a name="line.7"></a>
+<span class="sourceLineNo">008</span> * with the License.  You may obtain a copy of the License at<a name="line.8"></a>
+<span class="sourceLineNo">009</span> *<a name="line.9"></a>
+<span class="sourceLineNo">010</span> *     http://www.apache.org/licenses/LICENSE-2.0<a name="line.10"></a>
+<span class="sourceLineNo">011</span> *<a name="line.11"></a>
+<span class="sourceLineNo">012</span> * Unless required by applicable law or agreed to in writing, software<a name="line.12"></a>
+<span class="sourceLineNo">013</span> * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.13"></a>
+<span class="sourceLineNo">014</span> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.14"></a>
+<span class="sourceLineNo">015</span> * See the License for the specific language governing permissions and<a name="line.15"></a>
+<span class="sourceLineNo">016</span> * limitations under the License.<a name="line.16"></a>
+<span class="sourceLineNo">017</span> */<a name="line.17"></a>
+<span class="sourceLineNo">018</span>package org.apache.hadoop.hbase.master.balancer;<a name="line.18"></a>
+<span class="sourceLineNo">019</span><a name="line.19"></a>
+<span class="sourceLineNo">020</span>import java.util.ArrayDeque;<a name="line.20"></a>
+<span class="sourceLineNo">021</span>import java.util.ArrayList;<a name="line.21"></a>
+<span class="sourceLineNo">022</span>import java.util.Arrays;<a name="line.22"></a>
+<span class="sourceLineNo">023</span>import java.util.Collection;<a name="line.23"></a>
+<span class="sourceLineNo">024</span>import java.util.Collections;<a name="line.24"></a>
+<span class="sourceLineNo">025</span>import java.util.Deque;<a name="line.25"></a>
+<span class="sourceLineNo">026</span>import java.util.HashMap;<a name="line.26"></a>
+<span class="sourceLineNo">027</span>import java.util.LinkedList;<a name="line.27"></a>
+<span class="sourceLineNo">028</span>import java.util.List;<a name="line.28"></a>
+<span class="sourceLineNo">029</span>import java.util.Map;<a name="line.29"></a>
+<span class="sourceLineNo">030</span>import java.util.Map.Entry;<a name="line.30"></a>
+<span class="sourceLineNo">031</span>import java.util.Random;<a name="line.31"></a>
+<span class="sourceLineNo">032</span><a name="line.32"></a>
+<span class="sourceLineNo">033</span>import org.apache.commons.logging.Log;<a name="line.33"></a>
+<span class="sourceLineNo">034</span>import org.apache.commons.logging.LogFactory;<a name="line.34"></a>
+<span class="sourceLineNo">035</span>import org.apache.hadoop.conf.Configuration;<a name="line.35"></a>
+<span class="sourceLineNo">036</span>import org.apache.hadoop.hbase.ClusterStatus;<a name="line.36"></a>
+<span class="sourceLineNo">037</span>import org.apache.hadoop.hbase.HBaseInterfaceAudience;<a name="line.37"></a>
+<span class="sourceLineNo">038</span>import org.apache.hadoop.hbase.HConstants;<a name="line.38"></a>
+<span class="sourceLineNo">039</span>import org.apache.hadoop.hbase.HRegionInfo;<a name="line.39"></a>
+<span class="sourceLineNo">040</span>import org.apache.hadoop.hbase.RegionLoad;<a name="line.40"></a>
+<span class="sourceLineNo">041</span>import org.apache.hadoop.hbase.ServerLoad;<a name="line.41"></a>
+<span class="sourceLineNo">042</span>import org.apache.hadoop.hbase.ServerName;<a name="line.42"></a>
+<span class="sourceLineNo">043</span>import org.apache.hadoop.hbase.TableName;<a name="line.43"></a>
+<span class="sourceLineNo">044</span>import org.apache.hadoop.hbase.classification.InterfaceAudience;<a name="line.44"></a>
+<span class="sourceLineNo">045</span>import org.apache.hadoop.hbase.master.MasterServices;<a name="line.45"></a>
+<span class="sourceLineNo">046</span>import org.apache.hadoop.hbase.master.RegionPlan;<a name="line.46"></a>
+<span class="sourceLineNo">047</span>import org.apache.hadoop.hbase.master.balancer.BaseLoadBalancer.Cluster.Action;<a name="line.47"></a>
+<span class="sourceLineNo">048</span>import org.apache.hadoop.hbase.master.balancer.BaseLoadBalancer.Cluster.Action.Type;<a name="line.48"></a>
+<span class="sourceLineNo">049</span>import org.apache.hadoop.hbase.master.balancer.BaseLoadBalancer.Cluster.AssignRegionAction;<a name="line.49"></a>
+<span class="sourceLineNo">050</span>import org.apache.hadoop.hbase.master.balancer.BaseLoadBalancer.Cluster.LocalityType;<a name="line.50"></a>
+<span class="sourceLineNo">051</span>import org.apache.hadoop.hbase.master.balancer.BaseLoadBalancer.Cluster.MoveRegionAction;<a name="line.51"></a>
+<span class="sourceLineNo">052</span>import org.apache.hadoop.hbase.master.balancer.BaseLoadBalancer.Cluster.SwapRegionsAction;<a name="line.52"></a>
+<span class="sourceLineNo">053</span>import org.apache.hadoop.hbase.util.Bytes;<a name="line.53"></a>
+<span class="sourceLineNo">054</span>import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;<a name="line.54"></a>
+<span class="sourceLineNo">055</span><a name="line.55"></a>
+<span class="sourceLineNo">056</span>import com.google.common.base.Optional;<a name="line.56"></a>
+<span class="sourceLineNo">057</span>import com.google.common.collect.Lists;<a name="line.57"></a>
+<span class="sourceLineNo">058</span><a name="line.58"></a>
+<span class="sourceLineNo">059</span>/**<a name="line.59"></a>
+<span class="sourceLineNo">060</span> * &lt;p&gt;This is a best effort load balancer. Given a Cost function F(C) =&amp;gt; x It will<a name="line.60"></a>
+<span class="sourceLineNo">061</span> * randomly try and mutate the cluster to Cprime. If F(Cprime) &amp;lt; F(C) then the<a name="line.61"></a>
+<span class="sourceLineNo">062</span> * new cluster state becomes the plan. It includes costs functions to compute the cost of:&lt;/p&gt;<a name="line.62"></a>
+<span class="sourceLineNo">063</span> * &lt;ul&gt;<a name="line.63"></a>
+<span class="sourceLineNo">064</span> * &lt;li&gt;Region Load&lt;/li&gt;<a name="line.64"></a>
+<span class="sourceLineNo">065</span> * &lt;li&gt;Table Load&lt;/li&gt;<a name="line.65"></a>
+<span class="sourceLineNo">066</span> * &lt;li&gt;Data Locality&lt;/li&gt;<a name="line.66"></a>
+<span class="sourceLineNo">067</span> * &lt;li&gt;Memstore Sizes&lt;/li&gt;<a name="line.67"></a>
+<span class="sourceLineNo">068</span> * &lt;li&gt;Storefile Sizes&lt;/li&gt;<a name="line.68"></a>
+<span class="sourceLineNo">069</span> * &lt;/ul&gt;<a name="line.69"></a>
+<span class="sourceLineNo">070</span> *<a name="line.70"></a>
+<span class="sourceLineNo">071</span> *<a name="line.71"></a>
+<span class="sourceLineNo">072</span> * &lt;p&gt;Every cost function returns a number between 0 and 1 inclusive; where 0 is the lowest cost<a name="line.72"></a>
+<span class="sourceLineNo">073</span> * best solution, and 1 is the highest possible cost and the worst solution.  The computed costs are<a name="line.73"></a>
+<span class="sourceLineNo">074</span> * scaled by their respective multipliers:&lt;/p&gt;<a name="line.74"></a>
+<span class="sourceLineNo">075</span> *<a name="line.75"></a>
+<span class="sourceLineNo">076</span> * &lt;ul&gt;<a name="line.76"></a>
+<span class="sourceLineNo">077</span> *   &lt;li&gt;hbase.master.balancer.stochastic.regionLoadCost&lt;/li&gt;<a name="line.77"></a>
+<span class="sourceLineNo">078</span> *   &lt;li&gt;hbase.master.balancer.stochastic.moveCost&lt;/li&gt;<a name="line.78"></a>
+<span class="sourceLineNo">079</span> *   &lt;li&gt;hbase.master.balancer.stochastic.tableLoadCost&lt;/li&gt;<a name="line.79"></a>
+<span class="sourceLineNo">080</span> *   &lt;li&gt;hbase.master.balancer.stochastic.localityCost&lt;/li&gt;<a name="line.80"></a>
+<span class="sourceLineNo">081</span> *   &lt;li&gt;hbase.master.balancer.stochastic.memstoreSizeCost&lt;/li&gt;<a name="line.81"></a>
+<span class="sourceLineNo">082</span> *   &lt;li&gt;hbase.master.balancer.stochastic.storefileSizeCost&lt;/li&gt;<a name="line.82"></a>
+<span class="sourceLineNo">083</span> * &lt;/ul&gt;<a name="line.83"></a>
+<span class="sourceLineNo">084</span> *<a name="line.84"></a>
+<span class="sourceLineNo">085</span> * &lt;p&gt;In addition to the above configurations, the balancer can be tuned by the following<a name="line.85"></a>
+<span class="sourceLineNo">086</span> * configuration values:&lt;/p&gt;<a name="line.86"></a>
+<span class="sourceLineNo">087</span> * &lt;ul&gt;<a name="line.87"></a>
+<span class="sourceLineNo">088</span> *   &lt;li&gt;hbase.master.balancer.stochastic.maxMoveRegions which<a name="line.88"></a>
+<span class="sourceLineNo">089</span> *   controls what the max number of regions that can be moved in a single invocation of this<a name="line.89"></a>
+<span class="sourceLineNo">090</span> *   balancer.&lt;/li&gt;<a name="line.90"></a>
+<span class="sourceLineNo">091</span> *   &lt;li&gt;hbase.master.balancer.stochastic.stepsPerRegion is the coefficient by which the number of<a name="line.91"></a>
+<span class="sourceLineNo">092</span> *   regions is multiplied to try and get the number of times the balancer will<a name="line.92"></a>
+<span class="sourceLineNo">093</span> *   mutate all servers.&lt;/li&gt;<a name="line.93"></a>
+<span class="sourceLineNo">094</span> *   &lt;li&gt;hbase.master.balancer.stochastic.maxSteps which controls the maximum number of times that<a name="line.94"></a>
+<span class="sourceLineNo">095</span> *   the balancer will try and mutate all the servers. The balancer will use the minimum of this<a name="line.95"></a>
+<span class="sourceLineNo">096</span> *   value and the above computation.&lt;/li&gt;<a name="line.96"></a>
+<span class="sourceLineNo">097</span> * &lt;/ul&gt;<a name="line.97"></a>
+<span class="sourceLineNo">098</span> *<a name="line.98"></a>
+<span class="sourceLineNo">099</span> * &lt;p&gt;This balancer is best used with hbase.master.loadbalance.bytable set to false<a name="line.99"></a>
+<span class="sourceLineNo">100</span> * so that the balancer gets the full picture of all loads on the cluster.&lt;/p&gt;<a name="line.100"></a>
+<span class="sourceLineNo">101</span> */<a name="line.101"></a>
+<span class="sourceLineNo">102</span>@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.CONFIG)<a name="line.102"></a>
+<span class="sourceLineNo">103</span>@edu.umd.cs.findbugs.annotations.SuppressWarnings(value="IS2_INCONSISTENT_SYNC",<a name="line.103"></a>
+<span class="sourceLineNo">104</span>  justification="Complaint is about costFunctions not being synchronized; not end of the world")<a name="line.104"></a>
+<span class="sourceLineNo">105</span>public class StochasticLoadBalancer extends BaseLoadBalancer {<a name="line.105"></a>
+<span class="sourceLineNo">106</span><a name="line.106"></a>
+<span class="sourceLineNo">107</span>  protected static final String STEPS_PER_REGION_KEY =<a name="line.107"></a>
+<span class="sourceLineNo">108</span>      "hbase.master.balancer.stochastic.stepsPerRegion";<a name="line.108"></a>
+<span class="sourceLineNo">109</span>  protected static final String MAX_STEPS_KEY =<a name="line.109"></a>
+<span class="sourceLineNo">110</span>      "hbase.master.balancer.stochastic.maxSteps";<a name="line.110"></a>
+<span class="sourceLineNo">111</span>  protected static final String RUN_MAX_STEPS_KEY =<a name="line.111"></a>
+<span class="sourceLineNo">112</span>      "hbase.master.balancer.stochastic.runMaxSteps";<a name="line.112"></a>
+<span class="sourceLineNo">113</span>  protected static final String MAX_RUNNING_TIME_KEY =<a name="line.113"></a>
+<span class="sourceLineNo">114</span>      "hbase.master.balancer.stochastic.maxRunningTime";<a name="line.114"></a>
+<span class="sourceLineNo">115</span>  protected static final String KEEP_REGION_LOADS =<a name="line.115"></a>
+<span class="sourceLineNo">116</span>      "hbase.master.balancer.stochastic.numRegionLoadsToRemember";<a name="line.116"></a>
+<span class="sourceLineNo">117</span>  private static final String TABLE_FUNCTION_SEP = "_";<a name="line.117"></a>
+<span class="sourceLineNo">118</span>  protected static final String MIN_COST_NEED_BALANCE_KEY =<a name="line.118"></a>
+<span class="sourceLineNo">119</span>      "hbase.master.balancer.stochastic.minCostNeedBalance";<a name="line.119"></a>
+<span class="sourceLineNo">120</span><a name="line.120"></a>
+<span class="sourceLineNo">121</span>  protected static final Random RANDOM = new Random(System.currentTimeMillis());<a name="line.121"></a>
+<span class="sourceLineNo">122</span>  private static final Log LOG = LogFactory.getLog(StochasticLoadBalancer.class);<a name="line.122"></a>
+<span class="sourceLineNo">123</span><a name="line.123"></a>
+<span class="sourceLineNo">124</span>  Map&lt;String, Deque&lt;BalancerRegionLoad&gt;&gt; loads = new HashMap&lt;&gt;();<a name="line.124"></a>
+<span class="sourceLineNo">125</span><a name="line.125"></a>
+<span class="sourceLineNo">126</span>  // values are defaults<a name="line.126"></a>
+<span class="sourceLineNo">127</span>  private int maxSteps = 1000000;<a name="line.127"></a>
+<span class="sourceLineNo">128</span>  private boolean runMaxSteps = false;<a name="line.128"></a>
+<span class="sourceLineNo">129</span>  private int stepsPerRegion = 800;<a name="line.129"></a>
+<span class="sourceLineNo">130</span>  private long maxRunningTime = 30 * 1000 * 1; // 30 seconds.<a name="line.130"></a>
+<span class="sourceLineNo">131</span>  private int numRegionLoadsToRemember = 15;<a name="line.131"></a>
+<span class="sourceLineNo">132</span>  private float minCostNeedBalance = 0.05f;<a name="line.132"></a>
+<span class="sourceLineNo">133</span><a name="line.133"></a>
+<span class="sourceLineNo">134</span>  private List&lt;CandidateGenerator&gt; candidateGenerators;<a name="line.134"></a>
+<span class="sourceLineNo">135</span>  private CostFromRegionLoadFunction[] regionLoadFunctions;<a name="line.135"></a>
+<span class="sourceLineNo">136</span>  private CostFunction[] costFunctions; // FindBugs: Wants this protected; IS2_INCONSISTENT_SYNC<a name="line.136"></a>
+<span class="sourceLineNo">137</span><a name="line.137"></a>
+<span class="sourceLineNo">138</span>  // to save and report costs to JMX<a name="line.138"></a>
+<span class="sourceLineNo">139</span>  private Double curOverallCost = 0d;<a name="line.139"></a>
+<span class="sourceLineNo">140</span>  private Double[] tempFunctionCosts;<a name="line.140"></a>
+<span class="sourceLineNo">141</span>  private Double[] curFunctionCosts;<a name="line.141"></a>
+<span class="sourceLineNo">142</span><a name="line.142"></a>
+<span class="sourceLineNo">143</span>  // Keep locality based picker and cost function to alert them<a name="line.143"></a>
+<span class="sourceLineNo">144</span>  // when new services are offered<a name="line.144"></a>
+<span class="sourceLineNo">145</span>  private LocalityBasedCandidateGenerator localityCandidateGenerator;<a name="line.145"></a>
+<span class="sourceLineNo">146</span>  private ServerLocalityCostFunction localityCost;<a name="line.146"></a>
+<span class="sourceLineNo">147</span>  private RackLocalityCostFunction rackLocalityCost;<a name="line.147"></a>
+<span class="sourceLineNo">148</span>  private RegionReplicaHostCostFunction regionReplicaHostCostFunction;<a name="line.148"></a>
+<span class="sourceLineNo">149</span>  private RegionReplicaRackCostFunction regionReplicaRackCostFunction;<a name="line.149"></a>
+<span class="sourceLineNo">150</span>  private boolean isByTable = false;<a name="line.150"></a>
+<span class="sourceLineNo">151</span>  private TableName tableName = null;<a name="line.151"></a>
+<span class="sourceLineNo">152</span><a name="line.152"></a>
+<span class="sourceLineNo">153</span>  /**<a name="line.153"></a>
+<span class="sourceLineNo">154</span>   * The constructor that pass a MetricsStochasticBalancer to BaseLoadBalancer to replace its<a name="line.154"></a>
+<span class="sourceLineNo">155</span>   * default MetricsBalancer<a name="line.155"></a>
+<span class="sourceLineNo">156</span>   */<a name="line.156"></a>
+<span class="sourceLineNo">157</span>  public StochasticLoadBalancer() {<a name="line.157"></a>
+<span class="sourceLineNo">158</span>    super(new MetricsStochasticBalancer());<a name="line.158"></a>
+<span class="sourceLineNo">159</span>  }<a name="line.159"></a>
+<span class="sourceLineNo">160</span><a name="line.160"></a>
+<span class="sourceLineNo">161</span>  @Override<a name="line.161"></a>
+<span class="sourceLineNo">162</span>  public void onConfigurationChange(Configuration conf) {<a name="line.162"></a>
+<span class="sourceLineNo">163</span>    setConf(conf);<a name="line.163"></a>
+<span class="sourceLineNo">164</span>  }<a name="line.164"></a>
+<span class="sourceLineNo">165</span><a name="line.165"></a>
+<span class="sourceLineNo">166</span>  @Override<a name="line.166"></a>
+<span class="sourceLineNo">167</span>  public synchronized void setConf(Configuration conf) {<a name="line.167"></a>
+<span class="sourceLineNo">168</span>    super.setConf(conf);<a name="line.168"></a>
+<span class="sourceLineNo">169</span>    maxSteps = conf.getInt(MAX_STEPS_KEY, maxSteps);<a name="line.169"></a>
+<span class="sourceLineNo">170</span>    stepsPerRegion = conf.getInt(STEPS_PER_REGION_KEY, stepsPerRegion);<a name="line.170"></a>
+<span class="sourceLineNo">171</span>    maxRunningTime = conf.getLong(MAX_RUNNING_TIME_KEY, maxRunningTime);<a name="line.171"></a>
+<span class="sourceLineNo">172</span>    runMaxSteps = conf.getBoolean(RUN_MAX_STEPS_KEY, runMaxSteps);<a name="line.172"></a>
+<span class="sourceLineNo">173</span><a name="line.173"></a>
+<span class="sourceLineNo">174</span>    numRegionLoadsToRemember = conf.getInt(KEEP_REGION_LOADS, numRegionLoadsToRemember);<a name="line.174"></a>
+<span class="sourceLineNo">175</span>    isByTable = conf.getBoolean(HConstants.HBASE_MASTER_LOADBALANCE_BYTABLE, isByTable);<a name="line.175"></a>
+<span class="sourceLineNo">176</span>    minCostNeedBalance = conf.getFloat(MIN_COST_NEED_BALANCE_KEY, minCostNeedBalance);<a name="line.176"></a>
+<span class="sourceLineNo">177</span>    if (localityCandidateGenerator == null) {<a name="line.177"></a>
+<span class="sourceLineNo">178</span>      localityCandidateGenerator = new LocalityBasedCandidateGenerator(services);<a name="line.178"></a>
+<span class="sourceLineNo">179</span>    }<a name="line.179"></a>
+<span class="sourceLineNo">180</span>    localityCost = new ServerLocalityCostFunction(conf, services);<a name="line.180"></a>
+<span class="sourceLineNo">181</span>    rackLocalityCost = new RackLocalityCostFunction(conf, services);<a name="line.181"></a>
+<span class="sourceLineNo">182</span><a name="line.182"></a>
+<span class="sourceLineNo">183</span>    if (this.candidateGenerators == null) {<a name="line.183"></a>
+<span class="sourceLineNo">184</span>      candidateGenerators = Lists.newArrayList();<a name="line.184"></a>
+<span class="sourceLineNo">185</span>      candidateGenerators.add(new RandomCandidateGenerator());<a name="line.185"></a>
+<span class="sourceLineNo">186</span>      candidateGenerators.add(new LoadCandidateGenerator());<a name="line.186"></a>
+<span class="sourceLineNo">187</span>      candidateGenerators.add(localityCandidateGenerator);<a name="line.187"></a>
+<span class="sourceLineNo">188</span>      candidateGenerators.add(new RegionReplicaRackCandidateGenerator());<a name="line.188"></a>
+<span class="sourceLineNo">189</span>    }<a name="line.189"></a>
+<span class="sourceLineNo">190</span>    regionLoadFunctions = new CostFromRegionLoadFunction[] {<a name="line.190"></a>
+<span class="sourceLineNo">191</span>      new ReadRequestCostFunction(conf),<a name="line.191"></a>
+<span class="sourceLineNo">192</span>      new WriteRequestCostFunction(conf),<a name="line.192"></a>
+<span class="sourceLineNo">193</span>      new MemstoreSizeCostFunction(conf),<a name="line.193"></a>
+<span class="sourceLineNo">194</span>      new StoreFileCostFunction(conf)<a name="line.194"></a>
+<span class="sourceLineNo">195</span>    };<a name="line.195"></a>
+<span class="sourceLineNo">196</span>    regionReplicaHostCostFunction = new RegionReplicaHostCostFunction(conf);<a name="line.196"></a>
+<span class="sourceLineNo">197</span>    regionReplicaRackCostFunction = new RegionReplicaRackCostFunction(conf);<a name="line.197"></a>
+<span class="sourceLineNo">198</span>    costFunctions = new CostFunction[]{<a name="line.198"></a>
+<span class="sourceLineNo">199</span>      new RegionCountSkewCostFunction(conf),<a name="line.199"></a>
+<span class="sourceLineNo">200</span>      new PrimaryRegionCountSkewCostFunction(conf),<a name="line.200"></a>
+<span class="sourceLineNo">201</span>      new MoveCostFunction(conf),<a name="line.201"></a>
+<span class="sourceLineNo">202</span>      localityCost,<a name="line.202"></a>
+<span class="sourceLineNo">203</span>      rackLocalityCost,<a name="line.203"></a>
+<span class="sourceLineNo">204</span>      new TableSkewCostFunction(conf),<a name="line.204"></a>
+<span class="sourceLineNo">205</span>      regionReplicaHostCostFunction,<a name="line.205"></a>
+<span class="sourceLineNo">206</span>      regionReplicaRackCostFunction,<a name="line.206"></a>
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+<span class="sourceLineNo">852</span>   * co-hosted region replicas<a name="line.852"></a>
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+<span class="sourceLineNo">857</span><a name="line.857"></a>
+<span class="sourceLineNo">858</span>    /**<a name="line.858"></a>
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+<span class="sourceLineNo">883</span>            double currentRandom = RANDOM.nextDouble();<a name="line.883"></a>
+<span class="sourceLineNo">884</span>            // we don't know how many region replicas are co-hosted, we will randomly select one<a name="line.884"></a>
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+<span class="sourceL

<TRUNCATED>

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