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--- incubator/helix/site-content/xref/org/apache/helix/tools/IdealStateCalculatorForStorageNode.html (added)
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+<title>IdealStateCalculatorForStorageNode xref</title>
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+<div id="overview"><a href="../../../../../apidocs/org/apache/helix/tools/IdealStateCalculatorForStorageNode.html">View Javadoc</a></div><pre>
+
+<a class="jxr_linenumber" name="1" href="#1">1</a> <strong class="jxr_keyword">package</strong> org.apache.helix.tools;
+<a class="jxr_linenumber" name="2" href="#2">2</a>
+<a class="jxr_linenumber" name="3" href="#3">3</a> <em class="jxr_comment">/*</em>
+<a class="jxr_linenumber" name="4" href="#4">4</a> <em class="jxr_comment"> * Licensed to the Apache Software Foundation (ASF) under one</em>
+<a class="jxr_linenumber" name="5" href="#5">5</a> <em class="jxr_comment"> * or more contributor license agreements. See the NOTICE file</em>
+<a class="jxr_linenumber" name="6" href="#6">6</a> <em class="jxr_comment"> * distributed with this work for additional information</em>
+<a class="jxr_linenumber" name="7" href="#7">7</a> <em class="jxr_comment"> * regarding copyright ownership. The ASF licenses this file</em>
+<a class="jxr_linenumber" name="8" href="#8">8</a> <em class="jxr_comment"> * to you under the Apache License, Version 2.0 (the</em>
+<a class="jxr_linenumber" name="9" href="#9">9</a> <em class="jxr_comment"> * "License"); you may not use this file except in compliance</em>
+<a class="jxr_linenumber" name="10" href="#10">10</a> <em class="jxr_comment"> * with the License. You may obtain a copy of the License at</em>
+<a class="jxr_linenumber" name="11" href="#11">11</a> <em class="jxr_comment"> *</em>
+<a class="jxr_linenumber" name="12" href="#12">12</a> <em class="jxr_comment"> * <a href="http://www.apache.org/licenses/LICENSE-2.0" target="alexandria_uri">http://www.apache.org/licenses/LICENSE-2.0</a></em>
+<a class="jxr_linenumber" name="13" href="#13">13</a> <em class="jxr_comment"> *</em>
+<a class="jxr_linenumber" name="14" href="#14">14</a> <em class="jxr_comment"> * Unless required by applicable law or agreed to in writing,</em>
+<a class="jxr_linenumber" name="15" href="#15">15</a> <em class="jxr_comment"> * software distributed under the License is distributed on an</em>
+<a class="jxr_linenumber" name="16" href="#16">16</a> <em class="jxr_comment"> * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY</em>
+<a class="jxr_linenumber" name="17" href="#17">17</a> <em class="jxr_comment"> * KIND, either express or implied. See the License for the</em>
+<a class="jxr_linenumber" name="18" href="#18">18</a> <em class="jxr_comment"> * specific language governing permissions and limitations</em>
+<a class="jxr_linenumber" name="19" href="#19">19</a> <em class="jxr_comment"> * under the License.</em>
+<a class="jxr_linenumber" name="20" href="#20">20</a> <em class="jxr_comment"> */</em>
+<a class="jxr_linenumber" name="21" href="#21">21</a>
+<a class="jxr_linenumber" name="22" href="#22">22</a> <strong class="jxr_keyword">import</strong> java.util.ArrayList;
+<a class="jxr_linenumber" name="23" href="#23">23</a> <strong class="jxr_keyword">import</strong> java.util.Collections;
+<a class="jxr_linenumber" name="24" href="#24">24</a> <strong class="jxr_keyword">import</strong> java.util.List;
+<a class="jxr_linenumber" name="25" href="#25">25</a> <strong class="jxr_keyword">import</strong> java.util.Map;
+<a class="jxr_linenumber" name="26" href="#26">26</a> <strong class="jxr_keyword">import</strong> java.util.Random;
+<a class="jxr_linenumber" name="27" href="#27">27</a> <strong class="jxr_keyword">import</strong> java.util.TreeMap;
+<a class="jxr_linenumber" name="28" href="#28">28</a>
+<a class="jxr_linenumber" name="29" href="#29">29</a> <strong class="jxr_keyword">import</strong> org.apache.helix.HelixException;
+<a class="jxr_linenumber" name="30" href="#30">30</a> <strong class="jxr_keyword">import</strong> org.apache.helix.ZNRecord;
+<a class="jxr_linenumber" name="31" href="#31">31</a> <strong class="jxr_keyword">import</strong> org.apache.helix.model.IdealState.IdealStateProperty;
+<a class="jxr_linenumber" name="32" href="#32">32</a>
+<a class="jxr_linenumber" name="33" href="#33">33</a>
+<a class="jxr_linenumber" name="34" href="#34">34</a> <em class="jxr_javadoccomment">/**</em>
+<a class="jxr_linenumber" name="35" href="#35">35</a> <em class="jxr_javadoccomment"> * IdealStateCalculatorForStorageNode tries to optimally allocate master/slave partitions among</em>
+<a class="jxr_linenumber" name="36" href="#36">36</a> <em class="jxr_javadoccomment"> * espresso storage nodes.</em>
+<a class="jxr_linenumber" name="37" href="#37">37</a> <em class="jxr_javadoccomment"> *</em>
+<a class="jxr_linenumber" name="38" href="#38">38</a> <em class="jxr_javadoccomment"> * Given a batch of storage nodes, the partition and replication factor, the algorithm first given a initial state</em>
+<a class="jxr_linenumber" name="39" href="#39">39</a> <em class="jxr_javadoccomment"> * When new batches of storage nodes are added, the algorithm will calculate the new ideal state such that the total</em>
+<a class="jxr_linenumber" name="40" href="#40">40</a> <em class="jxr_javadoccomment"> * partition movements are minimized.</em>
+<a class="jxr_linenumber" name="41" href="#41">41</a> <em class="jxr_javadoccomment"> *</em>
+<a class="jxr_linenumber" name="42" href="#42">42</a> <em class="jxr_javadoccomment"> */</em>
+<a class="jxr_linenumber" name="43" href="#43">43</a> <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">class</strong> <a href="../../../../org/apache/helix/tools/IdealStateCalculatorForStorageNode.html">IdealStateCalculatorForStorageNode</a>
+<a class="jxr_linenumber" name="44" href="#44">44</a> {
+<a class="jxr_linenumber" name="45" href="#45">45</a> <strong class="jxr_keyword">static</strong> <strong class="jxr_keyword">final</strong> String _MasterAssignmentMap = <span class="jxr_string">"MasterAssignmentMap"</span>;
+<a class="jxr_linenumber" name="46" href="#46">46</a> <strong class="jxr_keyword">static</strong> <strong class="jxr_keyword">final</strong> String _SlaveAssignmentMap = <span class="jxr_string">"SlaveAssignmentMap"</span>;
+<a class="jxr_linenumber" name="47" href="#47">47</a> <strong class="jxr_keyword">static</strong> <strong class="jxr_keyword">final</strong> String _partitions = <span class="jxr_string">"partitions"</span>;
+<a class="jxr_linenumber" name="48" href="#48">48</a> <strong class="jxr_keyword">static</strong> <strong class="jxr_keyword">final</strong> String _replicas = <span class="jxr_string">"replicas"</span>;
+<a class="jxr_linenumber" name="49" href="#49">49</a>
+<a class="jxr_linenumber" name="50" href="#50">50</a> <em class="jxr_javadoccomment">/**</em>
+<a class="jxr_linenumber" name="51" href="#51">51</a> <em class="jxr_javadoccomment"> * Calculate the initial ideal state given a batch of storage instances, the replication factor and</em>
+<a class="jxr_linenumber" name="52" href="#52">52</a> <em class="jxr_javadoccomment"> * number of partitions</em>
+<a class="jxr_linenumber" name="53" href="#53">53</a> <em class="jxr_javadoccomment"> *</em>
+<a class="jxr_linenumber" name="54" href="#54">54</a> <em class="jxr_javadoccomment"> * 1. Calculate the master assignment by random shuffling</em>
+<a class="jxr_linenumber" name="55" href="#55">55</a> <em class="jxr_javadoccomment"> * 2. for each storage instance, calculate the 1st slave assignment map, by another random shuffling</em>
+<a class="jxr_linenumber" name="56" href="#56">56</a> <em class="jxr_javadoccomment"> * 3. for each storage instance, calculate the i-th slave assignment map</em>
+<a class="jxr_linenumber" name="57" href="#57">57</a> <em class="jxr_javadoccomment"> * 4. Combine the i-th slave assignment maps together</em>
+<a class="jxr_linenumber" name="58" href="#58">58</a> <em class="jxr_javadoccomment"> *</em>
+<a class="jxr_linenumber" name="59" href="#59">59</a> <em class="jxr_javadoccomment"> * @param instanceNames</em>
+<a class="jxr_linenumber" name="60" href="#60">60</a> <em class="jxr_javadoccomment"> * list of storage node instances</em>
+<a class="jxr_linenumber" name="61" href="#61">61</a> <em class="jxr_javadoccomment"> * @param partitions</em>
+<a class="jxr_linenumber" name="62" href="#62">62</a> <em class="jxr_javadoccomment"> * number of partitions</em>
+<a class="jxr_linenumber" name="63" href="#63">63</a> <em class="jxr_javadoccomment"> * @param replicas</em>
+<a class="jxr_linenumber" name="64" href="#64">64</a> <em class="jxr_javadoccomment"> * The number of replicas (slave partitions) per master partition</em>
+<a class="jxr_linenumber" name="65" href="#65">65</a> <em class="jxr_javadoccomment"> * @param masterStateValue</em>
+<a class="jxr_linenumber" name="66" href="#66">66</a> <em class="jxr_javadoccomment"> * master state value: e.g. "MASTER" or "LEADER"</em>
+<a class="jxr_linenumber" name="67" href="#67">67</a> <em class="jxr_javadoccomment"> * @param slaveStateValue</em>
+<a class="jxr_linenumber" name="68" href="#68">68</a> <em class="jxr_javadoccomment"> * slave state value: e.g. "SLAVE" or "STANDBY"</em>
+<a class="jxr_linenumber" name="69" href="#69">69</a> <em class="jxr_javadoccomment"> * @param resourceName</em>
+<a class="jxr_linenumber" name="70" href="#70">70</a> <em class="jxr_javadoccomment"> * @return a ZNRecord that contain the idealstate info</em>
+<a class="jxr_linenumber" name="71" href="#71">71</a> <em class="jxr_javadoccomment"> */</em>
+<a class="jxr_linenumber" name="72" href="#72">72</a> <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">static</strong> <a href="../../../../org/apache/helix/ZNRecord.html">ZNRecord</a> calculateIdealState(List<String> instanceNames, <strong class="jxr_keyword">int</strong> partitions, <strong class="jxr_keyword">int</strong> replicas, String resourceName,
+<a class="jxr_linenumber" name="73" href="#73">73</a> String masterStateValue, String slaveStateValue)
+<a class="jxr_linenumber" name="74" href="#74">74</a> {
+<a class="jxr_linenumber" name="75" href="#75">75</a> Collections.sort(instanceNames);
+<a class="jxr_linenumber" name="76" href="#76">76</a> <strong class="jxr_keyword">if</strong>(instanceNames.size() < replicas + 1)
+<a class="jxr_linenumber" name="77" href="#77">77</a> {
+<a class="jxr_linenumber" name="78" href="#78">78</a> <strong class="jxr_keyword">throw</strong> <strong class="jxr_keyword">new</strong> <a href="../../../../org/apache/helix/HelixException.html">HelixException</a>(<span class="jxr_string">"Number of instances must not be less than replicas + 1. "</span>
+<a class="jxr_linenumber" name="79" href="#79">79</a> + <span class="jxr_string">"instanceNr:"</span> + instanceNames.size()
+<a class="jxr_linenumber" name="80" href="#80">80</a> + <span class="jxr_string">", replicas:"</span> + replicas);
+<a class="jxr_linenumber" name="81" href="#81">81</a> }
+<a class="jxr_linenumber" name="82" href="#82">82</a> <strong class="jxr_keyword">else</strong> <strong class="jxr_keyword">if</strong>(partitions < instanceNames.size())
+<a class="jxr_linenumber" name="83" href="#83">83</a> {
+<a class="jxr_linenumber" name="84" href="#84">84</a> <a href="../../../../org/apache/helix/ZNRecord.html">ZNRecord</a> idealState = IdealStateCalculatorByShuffling.calculateIdealState(instanceNames, partitions, replicas, resourceName, 12345, masterStateValue, slaveStateValue);
+<a class="jxr_linenumber" name="85" href="#85">85</a> <strong class="jxr_keyword">int</strong> i = 0;
+<a class="jxr_linenumber" name="86" href="#86">86</a> <strong class="jxr_keyword">for</strong>(String partitionId : idealState.getMapFields().keySet())
+<a class="jxr_linenumber" name="87" href="#87">87</a> {
+<a class="jxr_linenumber" name="88" href="#88">88</a> Map<String, String> partitionAssignmentMap = idealState.getMapField(partitionId);
+<a class="jxr_linenumber" name="89" href="#89">89</a> List<String> partitionAssignmentPriorityList = <strong class="jxr_keyword">new</strong> ArrayList<String>();
+<a class="jxr_linenumber" name="90" href="#90">90</a> String masterInstance = <span class="jxr_string">""</span>;
+<a class="jxr_linenumber" name="91" href="#91">91</a> <strong class="jxr_keyword">for</strong>(String instanceName : partitionAssignmentMap.keySet())
+<a class="jxr_linenumber" name="92" href="#92">92</a> {
+<a class="jxr_linenumber" name="93" href="#93">93</a> <strong class="jxr_keyword">if</strong>(partitionAssignmentMap.get(instanceName).equalsIgnoreCase(masterStateValue)
+<a class="jxr_linenumber" name="94" href="#94">94</a> && masterInstance.equals(<span class="jxr_string">""</span>))
+<a class="jxr_linenumber" name="95" href="#95">95</a> {
+<a class="jxr_linenumber" name="96" href="#96">96</a> masterInstance = instanceName;
+<a class="jxr_linenumber" name="97" href="#97">97</a> }
+<a class="jxr_linenumber" name="98" href="#98">98</a> <strong class="jxr_keyword">else</strong>
+<a class="jxr_linenumber" name="99" href="#99">99</a> {
+<a class="jxr_linenumber" name="100" href="#100">100</a> partitionAssignmentPriorityList.add(instanceName);
+<a class="jxr_linenumber" name="101" href="#101">101</a> }
+<a class="jxr_linenumber" name="102" href="#102">102</a> }
+<a class="jxr_linenumber" name="103" href="#103">103</a> Collections.shuffle(partitionAssignmentPriorityList, <strong class="jxr_keyword">new</strong> Random(i++));
+<a class="jxr_linenumber" name="104" href="#104">104</a> partitionAssignmentPriorityList.add(0, masterInstance);
+<a class="jxr_linenumber" name="105" href="#105">105</a> idealState.setListField(partitionId, partitionAssignmentPriorityList);
+<a class="jxr_linenumber" name="106" href="#106">106</a> }
+<a class="jxr_linenumber" name="107" href="#107">107</a> <strong class="jxr_keyword">return</strong> idealState;
+<a class="jxr_linenumber" name="108" href="#108">108</a> }
+<a class="jxr_linenumber" name="109" href="#109">109</a>
+<a class="jxr_linenumber" name="110" href="#110">110</a> Map<String, Object> result = calculateInitialIdealState(instanceNames, partitions, replicas);
+<a class="jxr_linenumber" name="111" href="#111">111</a>
+<a class="jxr_linenumber" name="112" href="#112">112</a> <strong class="jxr_keyword">return</strong> convertToZNRecord(result, resourceName, masterStateValue, slaveStateValue);
+<a class="jxr_linenumber" name="113" href="#113">113</a> }
+<a class="jxr_linenumber" name="114" href="#114">114</a>
+<a class="jxr_linenumber" name="115" href="#115">115</a> <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">static</strong> <a href="../../../../org/apache/helix/ZNRecord.html">ZNRecord</a> calculateIdealStateBatch(List<List<String>> instanceBatches, <strong class="jxr_keyword">int</strong> partitions, <strong class="jxr_keyword">int</strong> replicas, String resourceName,
+<a class="jxr_linenumber" name="116" href="#116">116</a> String masterStateValue, String slaveStateValue)
+<a class="jxr_linenumber" name="117" href="#117">117</a> {
+<a class="jxr_linenumber" name="118" href="#118">118</a> Map<String, Object> result = calculateInitialIdealState(instanceBatches.get(0), partitions, replicas);
+<a class="jxr_linenumber" name="119" href="#119">119</a>
+<a class="jxr_linenumber" name="120" href="#120">120</a> <strong class="jxr_keyword">for</strong>(<strong class="jxr_keyword">int</strong> i = 1; i < instanceBatches.size(); i++)
+<a class="jxr_linenumber" name="121" href="#121">121</a> {
+<a class="jxr_linenumber" name="122" href="#122">122</a> result = calculateNextIdealState(instanceBatches.get(i), result);
+<a class="jxr_linenumber" name="123" href="#123">123</a> }
+<a class="jxr_linenumber" name="124" href="#124">124</a>
+<a class="jxr_linenumber" name="125" href="#125">125</a> <strong class="jxr_keyword">return</strong> convertToZNRecord(result, resourceName, masterStateValue, slaveStateValue);
+<a class="jxr_linenumber" name="126" href="#126">126</a> }
+<a class="jxr_linenumber" name="127" href="#127">127</a>
+<a class="jxr_linenumber" name="128" href="#128">128</a> <em class="jxr_javadoccomment">/**</em>
+<a class="jxr_linenumber" name="129" href="#129">129</a> <em class="jxr_javadoccomment"> * Convert the internal result (stored as a Map<String, Object>) into ZNRecord.</em>
+<a class="jxr_linenumber" name="130" href="#130">130</a> <em class="jxr_javadoccomment"> */</em>
+<a class="jxr_linenumber" name="131" href="#131">131</a> <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">static</strong> <a href="../../../../org/apache/helix/ZNRecord.html">ZNRecord</a> convertToZNRecord(Map<String, Object> result, String resourceName,
+<a class="jxr_linenumber" name="132" href="#132">132</a> String masterStateValue, String slaveStateValue)
+<a class="jxr_linenumber" name="133" href="#133">133</a> {
+<a class="jxr_linenumber" name="134" href="#134">134</a> Map<String, List<Integer>> nodeMasterAssignmentMap
+<a class="jxr_linenumber" name="135" href="#135">135</a> = (Map<String, List<Integer>>) (result.get(_MasterAssignmentMap));
+<a class="jxr_linenumber" name="136" href="#136">136</a> Map<String, Map<String, List<Integer>>> nodeSlaveAssignmentMap
+<a class="jxr_linenumber" name="137" href="#137">137</a> = (Map<String, Map<String, List<Integer>>>)(result.get(_SlaveAssignmentMap));
+<a class="jxr_linenumber" name="138" href="#138">138</a>
+<a class="jxr_linenumber" name="139" href="#139">139</a> <strong class="jxr_keyword">int</strong> partitions = (Integer)(result.get(<span class="jxr_string">"partitions"</span>));
+<a class="jxr_linenumber" name="140" href="#140">140</a>
+<a class="jxr_linenumber" name="141" href="#141">141</a> <a href="../../../../org/apache/helix/ZNRecord.html">ZNRecord</a> idealState = <strong class="jxr_keyword">new</strong> <a href="../../../../org/apache/helix/ZNRecord.html">ZNRecord</a>(resourceName);
+<a class="jxr_linenumber" name="142" href="#142">142</a> idealState.setSimpleField(IdealStateProperty.NUM_PARTITIONS.toString(), String.valueOf(partitions));
+<a class="jxr_linenumber" name="143" href="#143">143</a>
+<a class="jxr_linenumber" name="144" href="#144">144</a>
+<a class="jxr_linenumber" name="145" href="#145">145</a> <strong class="jxr_keyword">for</strong>(String instanceName : nodeMasterAssignmentMap.keySet())
+<a class="jxr_linenumber" name="146" href="#146">146</a> {
+<a class="jxr_linenumber" name="147" href="#147">147</a> <strong class="jxr_keyword">for</strong>(Integer partitionId : nodeMasterAssignmentMap.get(instanceName))
+<a class="jxr_linenumber" name="148" href="#148">148</a> {
+<a class="jxr_linenumber" name="149" href="#149">149</a> String partitionName = resourceName+<span class="jxr_string">"_"</span>+partitionId;
+<a class="jxr_linenumber" name="150" href="#150">150</a> <strong class="jxr_keyword">if</strong>(!idealState.getMapFields().containsKey(partitionName))
+<a class="jxr_linenumber" name="151" href="#151">151</a> {
+<a class="jxr_linenumber" name="152" href="#152">152</a> idealState.setMapField(partitionName, <strong class="jxr_keyword">new</strong> TreeMap<String, String>());
+<a class="jxr_linenumber" name="153" href="#153">153</a> }
+<a class="jxr_linenumber" name="154" href="#154">154</a> idealState.getMapField(partitionName).put(instanceName, masterStateValue);
+<a class="jxr_linenumber" name="155" href="#155">155</a> }
+<a class="jxr_linenumber" name="156" href="#156">156</a> }
+<a class="jxr_linenumber" name="157" href="#157">157</a>
+<a class="jxr_linenumber" name="158" href="#158">158</a> <strong class="jxr_keyword">for</strong>(String instanceName : nodeSlaveAssignmentMap.keySet())
+<a class="jxr_linenumber" name="159" href="#159">159</a> {
+<a class="jxr_linenumber" name="160" href="#160">160</a> Map<String, List<Integer>> slaveAssignmentMap = nodeSlaveAssignmentMap.get(instanceName);
+<a class="jxr_linenumber" name="161" href="#161">161</a>
+<a class="jxr_linenumber" name="162" href="#162">162</a> <strong class="jxr_keyword">for</strong>(String slaveNode: slaveAssignmentMap.keySet())
+<a class="jxr_linenumber" name="163" href="#163">163</a> {
+<a class="jxr_linenumber" name="164" href="#164">164</a> List<Integer> slaveAssignment = slaveAssignmentMap.get(slaveNode);
+<a class="jxr_linenumber" name="165" href="#165">165</a> <strong class="jxr_keyword">for</strong>(Integer partitionId: slaveAssignment)
+<a class="jxr_linenumber" name="166" href="#166">166</a> {
+<a class="jxr_linenumber" name="167" href="#167">167</a> String partitionName = resourceName+<span class="jxr_string">"_"</span>+partitionId;
+<a class="jxr_linenumber" name="168" href="#168">168</a> idealState.getMapField(partitionName).put(slaveNode, slaveStateValue);
+<a class="jxr_linenumber" name="169" href="#169">169</a> }
+<a class="jxr_linenumber" name="170" href="#170">170</a> }
+<a class="jxr_linenumber" name="171" href="#171">171</a> }
+<a class="jxr_linenumber" name="172" href="#172">172</a> <em class="jxr_comment">// generate the priority list of instances per partition. Master should be at front and slave follows.</em>
+<a class="jxr_linenumber" name="173" href="#173">173</a>
+<a class="jxr_linenumber" name="174" href="#174">174</a> <strong class="jxr_keyword">for</strong>(String partitionId : idealState.getMapFields().keySet())
+<a class="jxr_linenumber" name="175" href="#175">175</a> {
+<a class="jxr_linenumber" name="176" href="#176">176</a> Map<String, String> partitionAssignmentMap = idealState.getMapField(partitionId);
+<a class="jxr_linenumber" name="177" href="#177">177</a> List<String> partitionAssignmentPriorityList = <strong class="jxr_keyword">new</strong> ArrayList<String>();
+<a class="jxr_linenumber" name="178" href="#178">178</a> String masterInstance = <span class="jxr_string">""</span>;
+<a class="jxr_linenumber" name="179" href="#179">179</a> <strong class="jxr_keyword">for</strong>(String instanceName : partitionAssignmentMap.keySet())
+<a class="jxr_linenumber" name="180" href="#180">180</a> {
+<a class="jxr_linenumber" name="181" href="#181">181</a> <strong class="jxr_keyword">if</strong>(partitionAssignmentMap.get(instanceName).equalsIgnoreCase(masterStateValue)
+<a class="jxr_linenumber" name="182" href="#182">182</a> && masterInstance.equals(<span class="jxr_string">""</span>))
+<a class="jxr_linenumber" name="183" href="#183">183</a> {
+<a class="jxr_linenumber" name="184" href="#184">184</a> masterInstance = instanceName;
+<a class="jxr_linenumber" name="185" href="#185">185</a> }
+<a class="jxr_linenumber" name="186" href="#186">186</a> <strong class="jxr_keyword">else</strong>
+<a class="jxr_linenumber" name="187" href="#187">187</a> {
+<a class="jxr_linenumber" name="188" href="#188">188</a> partitionAssignmentPriorityList.add(instanceName);
+<a class="jxr_linenumber" name="189" href="#189">189</a> }
+<a class="jxr_linenumber" name="190" href="#190">190</a> }
+<a class="jxr_linenumber" name="191" href="#191">191</a> Collections.shuffle(partitionAssignmentPriorityList);
+<a class="jxr_linenumber" name="192" href="#192">192</a> partitionAssignmentPriorityList.add(0, masterInstance);
+<a class="jxr_linenumber" name="193" href="#193">193</a> idealState.setListField(partitionId, partitionAssignmentPriorityList);
+<a class="jxr_linenumber" name="194" href="#194">194</a> }
+<a class="jxr_linenumber" name="195" href="#195">195</a> assert(result.containsKey(<span class="jxr_string">"replicas"</span>));
+<a class="jxr_linenumber" name="196" href="#196">196</a> idealState.setSimpleField(IdealStateProperty.REPLICAS.toString(), result.get(<span class="jxr_string">"replicas"</span>).toString());
+<a class="jxr_linenumber" name="197" href="#197">197</a> <strong class="jxr_keyword">return</strong> idealState;
+<a class="jxr_linenumber" name="198" href="#198">198</a> }
+<a class="jxr_linenumber" name="199" href="#199">199</a> <em class="jxr_javadoccomment">/**</em>
+<a class="jxr_linenumber" name="200" href="#200">200</a> <em class="jxr_javadoccomment"> * Calculate the initial ideal state given a batch of storage instances, the replication factor and</em>
+<a class="jxr_linenumber" name="201" href="#201">201</a> <em class="jxr_javadoccomment"> * number of partitions</em>
+<a class="jxr_linenumber" name="202" href="#202">202</a> <em class="jxr_javadoccomment"> *</em>
+<a class="jxr_linenumber" name="203" href="#203">203</a> <em class="jxr_javadoccomment"> * 1. Calculate the master assignment by random shuffling</em>
+<a class="jxr_linenumber" name="204" href="#204">204</a> <em class="jxr_javadoccomment"> * 2. for each storage instance, calculate the 1st slave assignment map, by another random shuffling</em>
+<a class="jxr_linenumber" name="205" href="#205">205</a> <em class="jxr_javadoccomment"> * 3. for each storage instance, calculate the i-th slave assignment map</em>
+<a class="jxr_linenumber" name="206" href="#206">206</a> <em class="jxr_javadoccomment"> * 4. Combine the i-th slave assignment maps together</em>
+<a class="jxr_linenumber" name="207" href="#207">207</a> <em class="jxr_javadoccomment"> *</em>
+<a class="jxr_linenumber" name="208" href="#208">208</a> <em class="jxr_javadoccomment"> * @param instanceNames</em>
+<a class="jxr_linenumber" name="209" href="#209">209</a> <em class="jxr_javadoccomment"> * list of storage node instances</em>
+<a class="jxr_linenumber" name="210" href="#210">210</a> <em class="jxr_javadoccomment"> * @param weight</em>
+<a class="jxr_linenumber" name="211" href="#211">211</a> <em class="jxr_javadoccomment"> * weight for the initial storage node (each node has the same weight)</em>
+<a class="jxr_linenumber" name="212" href="#212">212</a> <em class="jxr_javadoccomment"> * @param partitions</em>
+<a class="jxr_linenumber" name="213" href="#213">213</a> <em class="jxr_javadoccomment"> * number of partitions</em>
+<a class="jxr_linenumber" name="214" href="#214">214</a> <em class="jxr_javadoccomment"> * @param replicas</em>
+<a class="jxr_linenumber" name="215" href="#215">215</a> <em class="jxr_javadoccomment"> * The number of replicas (slave partitions) per master partition</em>
+<a class="jxr_linenumber" name="216" href="#216">216</a> <em class="jxr_javadoccomment"> * @return a map that contain the idealstate info</em>
+<a class="jxr_linenumber" name="217" href="#217">217</a> <em class="jxr_javadoccomment"> */</em>
+<a class="jxr_linenumber" name="218" href="#218">218</a> <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">static</strong> Map<String, Object> calculateInitialIdealState(List<String> instanceNames, <strong class="jxr_keyword">int</strong> partitions, <strong class="jxr_keyword">int</strong> replicas)
+<a class="jxr_linenumber" name="219" href="#219">219</a> {
+<a class="jxr_linenumber" name="220" href="#220">220</a> Random r = <strong class="jxr_keyword">new</strong> Random(54321);
+<a class="jxr_linenumber" name="221" href="#221">221</a> assert(replicas <= instanceNames.size() - 1);
+<a class="jxr_linenumber" name="222" href="#222">222</a>
+<a class="jxr_linenumber" name="223" href="#223">223</a> ArrayList<Integer> masterPartitionAssignment = <strong class="jxr_keyword">new</strong> ArrayList<Integer>();
+<a class="jxr_linenumber" name="224" href="#224">224</a> <strong class="jxr_keyword">for</strong>(<strong class="jxr_keyword">int</strong> i = 0;i< partitions; i++)
+<a class="jxr_linenumber" name="225" href="#225">225</a> {
+<a class="jxr_linenumber" name="226" href="#226">226</a> masterPartitionAssignment.add(i);
+<a class="jxr_linenumber" name="227" href="#227">227</a> }
+<a class="jxr_linenumber" name="228" href="#228">228</a> <em class="jxr_comment">// shuffle the partition id array</em>
+<a class="jxr_linenumber" name="229" href="#229">229</a> Collections.shuffle(masterPartitionAssignment, <strong class="jxr_keyword">new</strong> Random(r.nextInt()));
+<a class="jxr_linenumber" name="230" href="#230">230</a>
+<a class="jxr_linenumber" name="231" href="#231">231</a> <em class="jxr_comment">// 1. Generate the random master partition assignment</em>
+<a class="jxr_linenumber" name="232" href="#232">232</a> <em class="jxr_comment">// instanceName -> List of master partitions on that instance</em>
+<a class="jxr_linenumber" name="233" href="#233">233</a> Map<String, List<Integer>> nodeMasterAssignmentMap = <strong class="jxr_keyword">new</strong> TreeMap<String, List<Integer>>();
+<a class="jxr_linenumber" name="234" href="#234">234</a> <strong class="jxr_keyword">for</strong>(<strong class="jxr_keyword">int</strong> i = 0; i < masterPartitionAssignment.size(); i++)
+<a class="jxr_linenumber" name="235" href="#235">235</a> {
+<a class="jxr_linenumber" name="236" href="#236">236</a> String instanceName = instanceNames.get(i % instanceNames.size());
+<a class="jxr_linenumber" name="237" href="#237">237</a> <strong class="jxr_keyword">if</strong>(!nodeMasterAssignmentMap.containsKey(instanceName))
+<a class="jxr_linenumber" name="238" href="#238">238</a> {
+<a class="jxr_linenumber" name="239" href="#239">239</a> nodeMasterAssignmentMap.put(instanceName, <strong class="jxr_keyword">new</strong> ArrayList<Integer>());
+<a class="jxr_linenumber" name="240" href="#240">240</a> }
+<a class="jxr_linenumber" name="241" href="#241">241</a> nodeMasterAssignmentMap.get(instanceName).add(masterPartitionAssignment.get(i));
+<a class="jxr_linenumber" name="242" href="#242">242</a> }
+<a class="jxr_linenumber" name="243" href="#243">243</a>
+<a class="jxr_linenumber" name="244" href="#244">244</a> <em class="jxr_comment">// instanceName -> slave assignment for its master partitions</em>
+<a class="jxr_linenumber" name="245" href="#245">245</a> <em class="jxr_comment">// slave assignment: instanceName -> list of slave partitions on it</em>
+<a class="jxr_linenumber" name="246" href="#246">246</a> List<Map<String, Map<String, List<Integer>>>> nodeSlaveAssignmentMapsList = <strong class="jxr_keyword">new</strong> ArrayList<Map<String, Map<String, List<Integer>>>>(replicas);
+<a class="jxr_linenumber" name="247" href="#247">247</a>
+<a class="jxr_linenumber" name="248" href="#248">248</a> Map<String, Map<String, List<Integer>>> firstNodeSlaveAssignmentMap = <strong class="jxr_keyword">new</strong> TreeMap<String, Map<String, List<Integer>>>();
+<a class="jxr_linenumber" name="249" href="#249">249</a> Map<String, Map<String, List<Integer>>> combinedNodeSlaveAssignmentMap = <strong class="jxr_keyword">new</strong> TreeMap<String, Map<String, List<Integer>>>();
+<a class="jxr_linenumber" name="250" href="#250">250</a>
+<a class="jxr_linenumber" name="251" href="#251">251</a> <strong class="jxr_keyword">if</strong>(replicas > 0)
+<a class="jxr_linenumber" name="252" href="#252">252</a> {
+<a class="jxr_linenumber" name="253" href="#253">253</a> <em class="jxr_comment">// 2. For each node, calculate the evenly distributed slave as the first slave assignment</em>
+<a class="jxr_linenumber" name="254" href="#254">254</a> <em class="jxr_comment">// We will figure out the 2nd ...replicas-th slave assignment based on the first level slave assignment</em>
+<a class="jxr_linenumber" name="255" href="#255">255</a> <strong class="jxr_keyword">for</strong>(<strong class="jxr_keyword">int</strong> i = 0; i < instanceNames.size(); i++)
+<a class="jxr_linenumber" name="256" href="#256">256</a> {
+<a class="jxr_linenumber" name="257" href="#257">257</a> List<String> slaveInstances = <strong class="jxr_keyword">new</strong> ArrayList<String>();
+<a class="jxr_linenumber" name="258" href="#258">258</a> ArrayList<Integer> slaveAssignment = <strong class="jxr_keyword">new</strong> ArrayList<Integer>();
+<a class="jxr_linenumber" name="259" href="#259">259</a> TreeMap<String, List<Integer>> slaveAssignmentMap = <strong class="jxr_keyword">new</strong> TreeMap<String, List<Integer>>();
+<a class="jxr_linenumber" name="260" href="#260">260</a>
+<a class="jxr_linenumber" name="261" href="#261">261</a> <strong class="jxr_keyword">for</strong>(<strong class="jxr_keyword">int</strong> j = 0;j < instanceNames.size(); j++)
+<a class="jxr_linenumber" name="262" href="#262">262</a> {
+<a class="jxr_linenumber" name="263" href="#263">263</a> <strong class="jxr_keyword">if</strong>(j != i)
+<a class="jxr_linenumber" name="264" href="#264">264</a> {
+<a class="jxr_linenumber" name="265" href="#265">265</a> slaveInstances.add(instanceNames.get(j));
+<a class="jxr_linenumber" name="266" href="#266">266</a> slaveAssignmentMap.put(instanceNames.get(j), <strong class="jxr_keyword">new</strong> ArrayList<Integer>());
+<a class="jxr_linenumber" name="267" href="#267">267</a> }
+<a class="jxr_linenumber" name="268" href="#268">268</a> }
+<a class="jxr_linenumber" name="269" href="#269">269</a> <em class="jxr_comment">// Get the number of master partitions on instanceName</em>
+<a class="jxr_linenumber" name="270" href="#270">270</a> List<Integer> masterAssignment = nodeMasterAssignmentMap.get(instanceNames.get(i));
+<a class="jxr_linenumber" name="271" href="#271">271</a> <em class="jxr_comment">// do a random shuffling as in step 1, so that the first-level slave are distributed among rest instances</em>
+<a class="jxr_linenumber" name="272" href="#272">272</a>
+<a class="jxr_linenumber" name="273" href="#273">273</a>
+<a class="jxr_linenumber" name="274" href="#274">274</a> <strong class="jxr_keyword">for</strong>(<strong class="jxr_keyword">int</strong> j = 0;j < masterAssignment.size(); j++)
+<a class="jxr_linenumber" name="275" href="#275">275</a> {
+<a class="jxr_linenumber" name="276" href="#276">276</a> slaveAssignment.add(j);
+<a class="jxr_linenumber" name="277" href="#277">277</a> }
+<a class="jxr_linenumber" name="278" href="#278">278</a> Collections.shuffle(slaveAssignment, <strong class="jxr_keyword">new</strong> Random(r.nextInt()));
+<a class="jxr_linenumber" name="279" href="#279">279</a>
+<a class="jxr_linenumber" name="280" href="#280">280</a> Collections.shuffle(slaveInstances, <strong class="jxr_keyword">new</strong> Random(instanceNames.get(i).hashCode()));
+<a class="jxr_linenumber" name="281" href="#281">281</a>
+<a class="jxr_linenumber" name="282" href="#282">282</a> <em class="jxr_comment">// Get the slave assignment map of node instanceName</em>
+<a class="jxr_linenumber" name="283" href="#283">283</a> <strong class="jxr_keyword">for</strong>(<strong class="jxr_keyword">int</strong> j = 0;j < masterAssignment.size(); j++)
+<a class="jxr_linenumber" name="284" href="#284">284</a> {
+<a class="jxr_linenumber" name="285" href="#285">285</a> String slaveInstanceName = slaveInstances.get(slaveAssignment.get(j) % slaveInstances.size());
+<a class="jxr_linenumber" name="286" href="#286">286</a> <strong class="jxr_keyword">if</strong>(!slaveAssignmentMap.containsKey(slaveInstanceName))
+<a class="jxr_linenumber" name="287" href="#287">287</a> {
+<a class="jxr_linenumber" name="288" href="#288">288</a> slaveAssignmentMap.put(slaveInstanceName, <strong class="jxr_keyword">new</strong> ArrayList<Integer>());
+<a class="jxr_linenumber" name="289" href="#289">289</a> }
+<a class="jxr_linenumber" name="290" href="#290">290</a> slaveAssignmentMap.get(slaveInstanceName).add(masterAssignment.get(j));
+<a class="jxr_linenumber" name="291" href="#291">291</a> }
+<a class="jxr_linenumber" name="292" href="#292">292</a> firstNodeSlaveAssignmentMap.put(instanceNames.get(i), slaveAssignmentMap);
+<a class="jxr_linenumber" name="293" href="#293">293</a> }
+<a class="jxr_linenumber" name="294" href="#294">294</a> nodeSlaveAssignmentMapsList.add(firstNodeSlaveAssignmentMap);
+<a class="jxr_linenumber" name="295" href="#295">295</a> <em class="jxr_comment">// From the first slave assignment map, calculate the rest slave assignment maps</em>
+<a class="jxr_linenumber" name="296" href="#296">296</a> <strong class="jxr_keyword">for</strong>(<strong class="jxr_keyword">int</strong> replicaOrder = 1; replicaOrder < replicas; replicaOrder++)
+<a class="jxr_linenumber" name="297" href="#297">297</a> {
+<a class="jxr_linenumber" name="298" href="#298">298</a> <em class="jxr_comment">// calculate the next slave partition assignment map</em>
+<a class="jxr_linenumber" name="299" href="#299">299</a> Map<String, Map<String, List<Integer>>> nextNodeSlaveAssignmentMap
+<a class="jxr_linenumber" name="300" href="#300">300</a> = calculateNextSlaveAssignemntMap(firstNodeSlaveAssignmentMap, replicaOrder);
+<a class="jxr_linenumber" name="301" href="#301">301</a> nodeSlaveAssignmentMapsList.add(nextNodeSlaveAssignmentMap);
+<a class="jxr_linenumber" name="302" href="#302">302</a> }
+<a class="jxr_linenumber" name="303" href="#303">303</a>
+<a class="jxr_linenumber" name="304" href="#304">304</a> <em class="jxr_comment">// Combine the calculated 1...replicas-th slave assignment map together</em>
+<a class="jxr_linenumber" name="305" href="#305">305</a>
+<a class="jxr_linenumber" name="306" href="#306">306</a> <strong class="jxr_keyword">for</strong>(String instanceName : nodeMasterAssignmentMap.keySet())
+<a class="jxr_linenumber" name="307" href="#307">307</a> {
+<a class="jxr_linenumber" name="308" href="#308">308</a> Map<String, List<Integer>> combinedSlaveAssignmentMap = <strong class="jxr_keyword">new</strong> TreeMap<String, List<Integer>>();
+<a class="jxr_linenumber" name="309" href="#309">309</a>
+<a class="jxr_linenumber" name="310" href="#310">310</a> <strong class="jxr_keyword">for</strong>(Map<String, Map<String, List<Integer>>> slaveNodeAssignmentMap : nodeSlaveAssignmentMapsList)
+<a class="jxr_linenumber" name="311" href="#311">311</a> {
+<a class="jxr_linenumber" name="312" href="#312">312</a> Map<String, List<Integer>> slaveAssignmentMap = slaveNodeAssignmentMap.get(instanceName);
+<a class="jxr_linenumber" name="313" href="#313">313</a>
+<a class="jxr_linenumber" name="314" href="#314">314</a> <strong class="jxr_keyword">for</strong>(String slaveInstance : slaveAssignmentMap.keySet())
+<a class="jxr_linenumber" name="315" href="#315">315</a> {
+<a class="jxr_linenumber" name="316" href="#316">316</a> <strong class="jxr_keyword">if</strong>(!combinedSlaveAssignmentMap.containsKey(slaveInstance))
+<a class="jxr_linenumber" name="317" href="#317">317</a> {
+<a class="jxr_linenumber" name="318" href="#318">318</a> combinedSlaveAssignmentMap.put(slaveInstance, <strong class="jxr_keyword">new</strong> ArrayList<Integer>());
+<a class="jxr_linenumber" name="319" href="#319">319</a> }
+<a class="jxr_linenumber" name="320" href="#320">320</a> combinedSlaveAssignmentMap.get(slaveInstance).addAll(slaveAssignmentMap.get(slaveInstance));
+<a class="jxr_linenumber" name="321" href="#321">321</a> }
+<a class="jxr_linenumber" name="322" href="#322">322</a> }
+<a class="jxr_linenumber" name="323" href="#323">323</a> migrateSlaveAssignMapToNewInstances(combinedSlaveAssignmentMap, <strong class="jxr_keyword">new</strong> ArrayList<String>());
+<a class="jxr_linenumber" name="324" href="#324">324</a> combinedNodeSlaveAssignmentMap.put(instanceName, combinedSlaveAssignmentMap);
+<a class="jxr_linenumber" name="325" href="#325">325</a> }
+<a class="jxr_linenumber" name="326" href="#326">326</a> }
+<a class="jxr_linenumber" name="327" href="#327">327</a> <em class="jxr_comment">/*</em>
+<a class="jxr_linenumber" name="328" href="#328">328</a> <em class="jxr_comment"> // Print the result master and slave assignment maps</em>
+<a class="jxr_linenumber" name="329" href="#329">329</a> <em class="jxr_comment"> System.out.println("Master assignment:");</em>
+<a class="jxr_linenumber" name="330" href="#330">330</a> <em class="jxr_comment"> for(String instanceName : nodeMasterAssignmentMap.keySet())</em>
+<a class="jxr_linenumber" name="331" href="#331">331</a> <em class="jxr_comment"> {</em>
+<a class="jxr_linenumber" name="332" href="#332">332</a> <em class="jxr_comment"> System.out.println(instanceName+":");</em>
+<a class="jxr_linenumber" name="333" href="#333">333</a> <em class="jxr_comment"> for(Integer x : nodeMasterAssignmentMap.get(instanceName))</em>
+<a class="jxr_linenumber" name="334" href="#334">334</a> <em class="jxr_comment"> {</em>
+<a class="jxr_linenumber" name="335" href="#335">335</a> <em class="jxr_comment"> System.out.print(x+" ");</em>
+<a class="jxr_linenumber" name="336" href="#336">336</a> <em class="jxr_comment"> }</em>
+<a class="jxr_linenumber" name="337" href="#337">337</a> <em class="jxr_comment"> System.out.println();</em>
+<a class="jxr_linenumber" name="338" href="#338">338</a> <em class="jxr_comment"> System.out.println("Slave assignment:");</em>
+<a class="jxr_linenumber" name="339" href="#339">339</a>
+<a class="jxr_linenumber" name="340" href="#340">340</a> <em class="jxr_comment"> int slaveOrder = 1;</em>
+<a class="jxr_linenumber" name="341" href="#341">341</a> <em class="jxr_comment"> for(Map<String, Map<String, List<Integer>>> slaveNodeAssignmentMap : nodeSlaveAssignmentMapsList)</em>
+<a class="jxr_linenumber" name="342" href="#342">342</a> <em class="jxr_comment"> {</em>
+<a class="jxr_linenumber" name="343" href="#343">343</a> <em class="jxr_comment"> System.out.println("Slave assignment order :" + (slaveOrder++));</em>
+<a class="jxr_linenumber" name="344" href="#344">344</a> <em class="jxr_comment"> Map<String, List<Integer>> slaveAssignmentMap = slaveNodeAssignmentMap.get(instanceName);</em>
+<a class="jxr_linenumber" name="345" href="#345">345</a> <em class="jxr_comment"> for(String slaveName : slaveAssignmentMap.keySet())</em>
+<a class="jxr_linenumber" name="346" href="#346">346</a> <em class="jxr_comment"> {</em>
+<a class="jxr_linenumber" name="347" href="#347">347</a> <em class="jxr_comment"> System.out.print("\t" + slaveName +":\n\t" );</em>
+<a class="jxr_linenumber" name="348" href="#348">348</a> <em class="jxr_comment"> for(Integer x : slaveAssignmentMap.get(slaveName))</em>
+<a class="jxr_linenumber" name="349" href="#349">349</a> <em class="jxr_comment"> {</em>
+<a class="jxr_linenumber" name="350" href="#350">350</a> <em class="jxr_comment"> System.out.print(x + " ");</em>
+<a class="jxr_linenumber" name="351" href="#351">351</a> <em class="jxr_comment"> }</em>
+<a class="jxr_linenumber" name="352" href="#352">352</a> <em class="jxr_comment"> System.out.println("\n");</em>
+<a class="jxr_linenumber" name="353" href="#353">353</a> <em class="jxr_comment"> }</em>
+<a class="jxr_linenumber" name="354" href="#354">354</a> <em class="jxr_comment"> }</em>
+<a class="jxr_linenumber" name="355" href="#355">355</a> <em class="jxr_comment"> System.out.println("\nCombined slave assignment map");</em>
+<a class="jxr_linenumber" name="356" href="#356">356</a> <em class="jxr_comment"> Map<String, List<Integer>> slaveAssignmentMap = combinedNodeSlaveAssignmentMap.get(instanceName);</em>
+<a class="jxr_linenumber" name="357" href="#357">357</a> <em class="jxr_comment"> for(String slaveName : slaveAssignmentMap.keySet())</em>
+<a class="jxr_linenumber" name="358" href="#358">358</a> <em class="jxr_comment"> {</em>
+<a class="jxr_linenumber" name="359" href="#359">359</a> <em class="jxr_comment"> System.out.print("\t" + slaveName +":\n\t" );</em>
+<a class="jxr_linenumber" name="360" href="#360">360</a> <em class="jxr_comment"> for(Integer x : slaveAssignmentMap.get(slaveName))</em>
+<a class="jxr_linenumber" name="361" href="#361">361</a> <em class="jxr_comment"> {</em>
+<a class="jxr_linenumber" name="362" href="#362">362</a> <em class="jxr_comment"> System.out.print(x + " ");</em>
+<a class="jxr_linenumber" name="363" href="#363">363</a> <em class="jxr_comment"> }</em>
+<a class="jxr_linenumber" name="364" href="#364">364</a> <em class="jxr_comment"> System.out.println("\n");</em>
+<a class="jxr_linenumber" name="365" href="#365">365</a> <em class="jxr_comment"> }</em>
+<a class="jxr_linenumber" name="366" href="#366">366</a> <em class="jxr_comment"> }*/</em>
+<a class="jxr_linenumber" name="367" href="#367">367</a> Map<String, Object> result = <strong class="jxr_keyword">new</strong> TreeMap<String, Object>();
+<a class="jxr_linenumber" name="368" href="#368">368</a> result.put(<span class="jxr_string">"MasterAssignmentMap"</span>, nodeMasterAssignmentMap);
+<a class="jxr_linenumber" name="369" href="#369">369</a> result.put(<span class="jxr_string">"SlaveAssignmentMap"</span>, combinedNodeSlaveAssignmentMap);
+<a class="jxr_linenumber" name="370" href="#370">370</a> result.put(<span class="jxr_string">"replicas"</span>, <strong class="jxr_keyword">new</strong> Integer(replicas));
+<a class="jxr_linenumber" name="371" href="#371">371</a> result.put(<span class="jxr_string">"partitions"</span>, <strong class="jxr_keyword">new</strong> Integer(partitions));
+<a class="jxr_linenumber" name="372" href="#372">372</a> <strong class="jxr_keyword">return</strong> result;
+<a class="jxr_linenumber" name="373" href="#373">373</a> }
+<a class="jxr_linenumber" name="374" href="#374">374</a> <em class="jxr_javadoccomment">/**</em>
+<a class="jxr_linenumber" name="375" href="#375">375</a> <em class="jxr_javadoccomment"> * In the case there are more than 1 slave, we use the following algorithm to calculate the n-th slave</em>
+<a class="jxr_linenumber" name="376" href="#376">376</a> <em class="jxr_javadoccomment"> * assignment map based on the first level slave assignment map.</em>
+<a class="jxr_linenumber" name="377" href="#377">377</a> <em class="jxr_javadoccomment"> *</em>
+<a class="jxr_linenumber" name="378" href="#378">378</a> <em class="jxr_javadoccomment"> * @param firstInstanceSlaveAssignmentMap the first slave assignment map for all instances</em>
+<a class="jxr_linenumber" name="379" href="#379">379</a> <em class="jxr_javadoccomment"> * @param order of the slave</em>
+<a class="jxr_linenumber" name="380" href="#380">380</a> <em class="jxr_javadoccomment"> * @return the n-th slave assignment map for all the instances</em>
+<a class="jxr_linenumber" name="381" href="#381">381</a> <em class="jxr_javadoccomment"> * */</em>
+<a class="jxr_linenumber" name="382" href="#382">382</a> <strong class="jxr_keyword">static</strong> Map<String, Map<String, List<Integer>>> calculateNextSlaveAssignemntMap(Map<String, Map<String, List<Integer>>> firstInstanceSlaveAssignmentMap, <strong class="jxr_keyword">int</strong> replicaOrder)
+<a class="jxr_linenumber" name="383" href="#383">383</a> {
+<a class="jxr_linenumber" name="384" href="#384">384</a> Map<String, Map<String, List<Integer>>> result = <strong class="jxr_keyword">new</strong> TreeMap<String, Map<String, List<Integer>>>();
+<a class="jxr_linenumber" name="385" href="#385">385</a>
+<a class="jxr_linenumber" name="386" href="#386">386</a> <strong class="jxr_keyword">for</strong>(String currentInstance : firstInstanceSlaveAssignmentMap.keySet())
+<a class="jxr_linenumber" name="387" href="#387">387</a> {
+<a class="jxr_linenumber" name="388" href="#388">388</a> Map<String, List<Integer>> resultAssignmentMap = <strong class="jxr_keyword">new</strong> TreeMap<String, List<Integer>>();
+<a class="jxr_linenumber" name="389" href="#389">389</a> result.put(currentInstance, resultAssignmentMap);
+<a class="jxr_linenumber" name="390" href="#390">390</a> }
+<a class="jxr_linenumber" name="391" href="#391">391</a>
+<a class="jxr_linenumber" name="392" href="#392">392</a> <strong class="jxr_keyword">for</strong>(String currentInstance : firstInstanceSlaveAssignmentMap.keySet())
+<a class="jxr_linenumber" name="393" href="#393">393</a> {
+<a class="jxr_linenumber" name="394" href="#394">394</a> Map<String, List<Integer>> previousSlaveAssignmentMap = firstInstanceSlaveAssignmentMap.get(currentInstance);
+<a class="jxr_linenumber" name="395" href="#395">395</a> Map<String, List<Integer>> resultAssignmentMap = result.get(currentInstance);
+<a class="jxr_linenumber" name="396" href="#396">396</a> <strong class="jxr_keyword">int</strong> offset = replicaOrder - 1;
+<a class="jxr_linenumber" name="397" href="#397">397</a> <strong class="jxr_keyword">for</strong>(String instance : previousSlaveAssignmentMap.keySet())
+<a class="jxr_linenumber" name="398" href="#398">398</a> {
+<a class="jxr_linenumber" name="399" href="#399">399</a> List<String> otherInstances = <strong class="jxr_keyword">new</strong> ArrayList<String>(previousSlaveAssignmentMap.size() - 1);
+<a class="jxr_linenumber" name="400" href="#400">400</a> <em class="jxr_comment">// Obtain an array of other instances</em>
+<a class="jxr_linenumber" name="401" href="#401">401</a> <strong class="jxr_keyword">for</strong>(String otherInstance : previousSlaveAssignmentMap.keySet())
+<a class="jxr_linenumber" name="402" href="#402">402</a> {
+<a class="jxr_linenumber" name="403" href="#403">403</a> otherInstances.add(otherInstance);
+<a class="jxr_linenumber" name="404" href="#404">404</a> }
+<a class="jxr_linenumber" name="405" href="#405">405</a> Collections.sort(otherInstances);
+<a class="jxr_linenumber" name="406" href="#406">406</a> <strong class="jxr_keyword">int</strong> instanceIndex = -1;
+<a class="jxr_linenumber" name="407" href="#407">407</a> <strong class="jxr_keyword">for</strong>(<strong class="jxr_keyword">int</strong> index = 0;index < otherInstances.size(); index++)
+<a class="jxr_linenumber" name="408" href="#408">408</a> {
+<a class="jxr_linenumber" name="409" href="#409">409</a> <strong class="jxr_keyword">if</strong>(otherInstances.get(index).equalsIgnoreCase(instance))
+<a class="jxr_linenumber" name="410" href="#410">410</a> {
+<a class="jxr_linenumber" name="411" href="#411">411</a> instanceIndex = index;
+<a class="jxr_linenumber" name="412" href="#412">412</a> }
+<a class="jxr_linenumber" name="413" href="#413">413</a> }
+<a class="jxr_linenumber" name="414" href="#414">414</a> assert(instanceIndex >= 0);
+<a class="jxr_linenumber" name="415" href="#415">415</a> <strong class="jxr_keyword">if</strong>(instanceIndex == otherInstances.size() - 1)
+<a class="jxr_linenumber" name="416" href="#416">416</a> {
+<a class="jxr_linenumber" name="417" href="#417">417</a> instanceIndex --;
+<a class="jxr_linenumber" name="418" href="#418">418</a> }
+<a class="jxr_linenumber" name="419" href="#419">419</a> <em class="jxr_comment">// Since we need to evenly distribute the slaves on "instance" to other partitions, we</em>
+<a class="jxr_linenumber" name="420" href="#420">420</a> <em class="jxr_comment">// need to remove "instance" from the array.</em>
+<a class="jxr_linenumber" name="421" href="#421">421</a> otherInstances.remove(instance);
+<a class="jxr_linenumber" name="422" href="#422">422</a>
+<a class="jxr_linenumber" name="423" href="#423">423</a> <em class="jxr_comment">// distribute previous slave assignment to other instances.</em>
+<a class="jxr_linenumber" name="424" href="#424">424</a> List<Integer> previousAssignmentList = previousSlaveAssignmentMap.get(instance);
+<a class="jxr_linenumber" name="425" href="#425">425</a> <strong class="jxr_keyword">for</strong>(<strong class="jxr_keyword">int</strong> i = 0; i < previousAssignmentList.size(); i++)
+<a class="jxr_linenumber" name="426" href="#426">426</a> {
+<a class="jxr_linenumber" name="427" href="#427">427</a>
+<a class="jxr_linenumber" name="428" href="#428">428</a> <em class="jxr_comment">// Evenly distribute the previousAssignmentList to the remaining other instances</em>
+<a class="jxr_linenumber" name="429" href="#429">429</a> <strong class="jxr_keyword">int</strong> newInstanceIndex = (i + offset + instanceIndex) % otherInstances.size();
+<a class="jxr_linenumber" name="430" href="#430">430</a> String newInstance = otherInstances.get(newInstanceIndex);
+<a class="jxr_linenumber" name="431" href="#431">431</a> <strong class="jxr_keyword">if</strong>(!resultAssignmentMap.containsKey(newInstance))
+<a class="jxr_linenumber" name="432" href="#432">432</a> {
+<a class="jxr_linenumber" name="433" href="#433">433</a> resultAssignmentMap.put(newInstance, <strong class="jxr_keyword">new</strong> ArrayList<Integer>());
+<a class="jxr_linenumber" name="434" href="#434">434</a> }
+<a class="jxr_linenumber" name="435" href="#435">435</a> resultAssignmentMap.get(newInstance).add(previousAssignmentList.get(i));
+<a class="jxr_linenumber" name="436" href="#436">436</a> }
+<a class="jxr_linenumber" name="437" href="#437">437</a> }
+<a class="jxr_linenumber" name="438" href="#438">438</a> }
+<a class="jxr_linenumber" name="439" href="#439">439</a> <strong class="jxr_keyword">return</strong> result;
+<a class="jxr_linenumber" name="440" href="#440">440</a> }
+<a class="jxr_linenumber" name="441" href="#441">441</a>
+<a class="jxr_linenumber" name="442" href="#442">442</a> <em class="jxr_javadoccomment">/**</em>
+<a class="jxr_linenumber" name="443" href="#443">443</a> <em class="jxr_javadoccomment"> * Given the current idealState, and the list of new Instances needed to be added, calculate the</em>
+<a class="jxr_linenumber" name="444" href="#444">444</a> <em class="jxr_javadoccomment"> * new Ideal state.</em>
+<a class="jxr_linenumber" name="445" href="#445">445</a> <em class="jxr_javadoccomment"> *</em>
+<a class="jxr_linenumber" name="446" href="#446">446</a> <em class="jxr_javadoccomment"> * 1. Calculate how many master partitions should be moved to the new cluster of instances</em>
+<a class="jxr_linenumber" name="447" href="#447">447</a> <em class="jxr_javadoccomment"> * 2. assign the number of master partitions px to be moved to each previous node</em>
+<a class="jxr_linenumber" name="448" href="#448">448</a> <em class="jxr_javadoccomment"> * 3. for each previous node,</em>
+<a class="jxr_linenumber" name="449" href="#449">449</a> <em class="jxr_javadoccomment"> * 3.1 randomly choose px nodes, move them to temp list</em>
+<a class="jxr_linenumber" name="450" href="#450">450</a> <em class="jxr_javadoccomment"> * 3.2 for each px nodes, remove them from the slave assignment map; record the map position of</em>
+<a class="jxr_linenumber" name="451" href="#451">451</a> <em class="jxr_javadoccomment"> * the partition;</em>
+<a class="jxr_linenumber" name="452" href="#452">452</a> <em class="jxr_javadoccomment"> * 3.3 calculate # of new nodes that should be put in the slave assignment map</em>
+<a class="jxr_linenumber" name="453" href="#453">453</a> <em class="jxr_javadoccomment"> * 3.4 even-fy the slave assignment map;</em>
+<a class="jxr_linenumber" name="454" href="#454">454</a> <em class="jxr_javadoccomment"> * 3.5 randomly place # of new nodes that should be placed in</em>
+<a class="jxr_linenumber" name="455" href="#455">455</a> <em class="jxr_javadoccomment"> *</em>
+<a class="jxr_linenumber" name="456" href="#456">456</a> <em class="jxr_javadoccomment"> * 4. from all the temp master node list get from 3.1,</em>
+<a class="jxr_linenumber" name="457" href="#457">457</a> <em class="jxr_javadoccomment"> * 4.1 randomly assign them to nodes in the new cluster</em>
+<a class="jxr_linenumber" name="458" href="#458">458</a> <em class="jxr_javadoccomment"> *</em>
+<a class="jxr_linenumber" name="459" href="#459">459</a> <em class="jxr_javadoccomment"> * 5. for each node in the new cluster,</em>
+<a class="jxr_linenumber" name="460" href="#460">460</a> <em class="jxr_javadoccomment"> * 5.1 assemble the slave assignment map</em>
+<a class="jxr_linenumber" name="461" href="#461">461</a> <em class="jxr_javadoccomment"> * 5.2 even-fy the slave assignment map</em>
+<a class="jxr_linenumber" name="462" href="#462">462</a> <em class="jxr_javadoccomment"> *</em>
+<a class="jxr_linenumber" name="463" href="#463">463</a> <em class="jxr_javadoccomment"> * @param newInstances</em>
+<a class="jxr_linenumber" name="464" href="#464">464</a> <em class="jxr_javadoccomment"> * list of new added storage node instances</em>
+<a class="jxr_linenumber" name="465" href="#465">465</a> <em class="jxr_javadoccomment"> * @param weight</em>
+<a class="jxr_linenumber" name="466" href="#466">466</a> <em class="jxr_javadoccomment"> * weight for the new storage nodes (each node has the same weight)</em>
+<a class="jxr_linenumber" name="467" href="#467">467</a> <em class="jxr_javadoccomment"> * @param previousIdealState</em>
+<a class="jxr_linenumber" name="468" href="#468">468</a> <em class="jxr_javadoccomment"> * The previous ideal state</em>
+<a class="jxr_linenumber" name="469" href="#469">469</a> <em class="jxr_javadoccomment"> * @return a map that contain the updated idealstate info</em>
+<a class="jxr_linenumber" name="470" href="#470">470</a> <em class="jxr_javadoccomment"> * */</em>
+<a class="jxr_linenumber" name="471" href="#471">471</a> <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">static</strong> Map<String, Object> calculateNextIdealState(List<String> newInstances, Map<String, Object> previousIdealState)
+<a class="jxr_linenumber" name="472" href="#472">472</a> {
+<a class="jxr_linenumber" name="473" href="#473">473</a> <em class="jxr_comment">// Obtain the master / slave assignment info maps</em>
+<a class="jxr_linenumber" name="474" href="#474">474</a> Collections.sort(newInstances);
+<a class="jxr_linenumber" name="475" href="#475">475</a> Map<String, List<Integer>> previousMasterAssignmentMap
+<a class="jxr_linenumber" name="476" href="#476">476</a> = (Map<String, List<Integer>>) (previousIdealState.get(<span class="jxr_string">"MasterAssignmentMap"</span>));
+<a class="jxr_linenumber" name="477" href="#477">477</a> Map<String, Map<String, List<Integer>>> nodeSlaveAssignmentMap
+<a class="jxr_linenumber" name="478" href="#478">478</a> = (Map<String, Map<String, List<Integer>>>)(previousIdealState.get(<span class="jxr_string">"SlaveAssignmentMap"</span>));
+<a class="jxr_linenumber" name="479" href="#479">479</a>
+<a class="jxr_linenumber" name="480" href="#480">480</a> List<String> oldInstances = <strong class="jxr_keyword">new</strong> ArrayList<String>();
+<a class="jxr_linenumber" name="481" href="#481">481</a> <strong class="jxr_keyword">for</strong>(String oldInstance : previousMasterAssignmentMap.keySet())
+<a class="jxr_linenumber" name="482" href="#482">482</a> {
+<a class="jxr_linenumber" name="483" href="#483">483</a> oldInstances.add(oldInstance);
+<a class="jxr_linenumber" name="484" href="#484">484</a> }
+<a class="jxr_linenumber" name="485" href="#485">485</a>
+<a class="jxr_linenumber" name="486" href="#486">486</a> <strong class="jxr_keyword">int</strong> previousInstanceNum = previousMasterAssignmentMap.size();
+<a class="jxr_linenumber" name="487" href="#487">487</a> <strong class="jxr_keyword">int</strong> partitions = (Integer)(previousIdealState.get(<span class="jxr_string">"partitions"</span>));
+<a class="jxr_linenumber" name="488" href="#488">488</a>
+<a class="jxr_linenumber" name="489" href="#489">489</a> <em class="jxr_comment">// TODO: take weight into account when calculate this</em>
+<a class="jxr_linenumber" name="490" href="#490">490</a>
+<a class="jxr_linenumber" name="491" href="#491">491</a> <strong class="jxr_keyword">int</strong> totalMasterParitionsToMove
+<a class="jxr_linenumber" name="492" href="#492">492</a> = partitions * (newInstances.size()) / (previousInstanceNum + newInstances.size());
+<a class="jxr_linenumber" name="493" href="#493">493</a> <strong class="jxr_keyword">int</strong> numMastersFromEachNode = totalMasterParitionsToMove / previousInstanceNum;
+<a class="jxr_linenumber" name="494" href="#494">494</a> <strong class="jxr_keyword">int</strong> remain = totalMasterParitionsToMove % previousInstanceNum;
+<a class="jxr_linenumber" name="495" href="#495">495</a>
+<a class="jxr_linenumber" name="496" href="#496">496</a> <em class="jxr_comment">// Note that when remain > 0, we should make [remain] moves with (numMastersFromEachNode + 1) partitions.</em>
+<a class="jxr_linenumber" name="497" href="#497">497</a> <em class="jxr_comment">// And we should first choose those (numMastersFromEachNode + 1) moves from the instances that has more</em>
+<a class="jxr_linenumber" name="498" href="#498">498</a> <em class="jxr_comment">// master partitions</em>
+<a class="jxr_linenumber" name="499" href="#499">499</a> List<Integer> masterPartitionListToMove = <strong class="jxr_keyword">new</strong> ArrayList<Integer>();
+<a class="jxr_linenumber" name="500" href="#500">500</a>
+<a class="jxr_linenumber" name="501" href="#501">501</a> <em class="jxr_comment">// For corresponding moved slave partitions, keep track of their original location; the new node does not</em>
+<a class="jxr_linenumber" name="502" href="#502">502</a> <em class="jxr_comment">// need to migrate all of them.</em>
+<a class="jxr_linenumber" name="503" href="#503">503</a> Map<String, List<Integer>> slavePartitionsToMoveMap = <strong class="jxr_keyword">new</strong> TreeMap<String, List<Integer>>();
+<a class="jxr_linenumber" name="504" href="#504">504</a>
+<a class="jxr_linenumber" name="505" href="#505">505</a> <em class="jxr_comment">// Make sure that the instances that holds more master partitions are put in front</em>
+<a class="jxr_linenumber" name="506" href="#506">506</a> List<String> bigList = <strong class="jxr_keyword">new</strong> ArrayList<String>(), smallList = <strong class="jxr_keyword">new</strong> ArrayList<String>();
+<a class="jxr_linenumber" name="507" href="#507">507</a> <strong class="jxr_keyword">for</strong>(String oldInstance : previousMasterAssignmentMap.keySet())
+<a class="jxr_linenumber" name="508" href="#508">508</a> {
+<a class="jxr_linenumber" name="509" href="#509">509</a> List<Integer> masterAssignmentList = previousMasterAssignmentMap.get(oldInstance);
+<a class="jxr_linenumber" name="510" href="#510">510</a> <strong class="jxr_keyword">if</strong>(masterAssignmentList.size() > numMastersFromEachNode)
+<a class="jxr_linenumber" name="511" href="#511">511</a> {
+<a class="jxr_linenumber" name="512" href="#512">512</a> bigList.add(oldInstance);
+<a class="jxr_linenumber" name="513" href="#513">513</a> }
+<a class="jxr_linenumber" name="514" href="#514">514</a> <strong class="jxr_keyword">else</strong>
+<a class="jxr_linenumber" name="515" href="#515">515</a> {
+<a class="jxr_linenumber" name="516" href="#516">516</a> smallList.add(oldInstance);
+<a class="jxr_linenumber" name="517" href="#517">517</a> }
+<a class="jxr_linenumber" name="518" href="#518">518</a> }
+<a class="jxr_linenumber" name="519" href="#519">519</a> <em class="jxr_comment">// "sort" the list, such that the nodes that has more master partitions moves more partitions to the</em>
+<a class="jxr_linenumber" name="520" href="#520">520</a> <em class="jxr_comment">// new added batch of instances.</em>
+<a class="jxr_linenumber" name="521" href="#521">521</a> bigList.addAll(smallList);
+<a class="jxr_linenumber" name="522" href="#522">522</a> <strong class="jxr_keyword">int</strong> totalSlaveMoves = 0;
+<a class="jxr_linenumber" name="523" href="#523">523</a> <strong class="jxr_keyword">for</strong>(String oldInstance : bigList)
+<a class="jxr_linenumber" name="524" href="#524">524</a> {
+<a class="jxr_linenumber" name="525" href="#525">525</a> List<Integer> masterAssignmentList = previousMasterAssignmentMap.get(oldInstance);
+<a class="jxr_linenumber" name="526" href="#526">526</a> <strong class="jxr_keyword">int</strong> numToChoose = numMastersFromEachNode;
+<a class="jxr_linenumber" name="527" href="#527">527</a> <strong class="jxr_keyword">if</strong>(remain > 0)
+<a class="jxr_linenumber" name="528" href="#528">528</a> {
+<a class="jxr_linenumber" name="529" href="#529">529</a> numToChoose = numMastersFromEachNode + 1;
+<a class="jxr_linenumber" name="530" href="#530">530</a> remain --;
+<a class="jxr_linenumber" name="531" href="#531">531</a> }
+<a class="jxr_linenumber" name="532" href="#532">532</a> <em class="jxr_comment">// randomly remove numToChoose of master partitions to the new added nodes</em>
+<a class="jxr_linenumber" name="533" href="#533">533</a> ArrayList<Integer> masterPartionsMoved = <strong class="jxr_keyword">new</strong> ArrayList<Integer>();
+<a class="jxr_linenumber" name="534" href="#534">534</a> randomSelect(masterAssignmentList, masterPartionsMoved, numToChoose);
+<a class="jxr_linenumber" name="535" href="#535">535</a>
+<a class="jxr_linenumber" name="536" href="#536">536</a> masterPartitionListToMove.addAll(masterPartionsMoved);
+<a class="jxr_linenumber" name="537" href="#537">537</a> Map<String, List<Integer>> slaveAssignmentMap = nodeSlaveAssignmentMap.get(oldInstance);
+<a class="jxr_linenumber" name="538" href="#538">538</a> removeFromSlaveAssignmentMap(slaveAssignmentMap, masterPartionsMoved, slavePartitionsToMoveMap);
+<a class="jxr_linenumber" name="539" href="#539">539</a>
+<a class="jxr_linenumber" name="540" href="#540">540</a> <em class="jxr_comment">// Make sure that for old instances, the slave placement map is evenly distributed</em>
+<a class="jxr_linenumber" name="541" href="#541">541</a> <em class="jxr_comment">// Trace the "local slave moves", which should together contribute to most of the slave migrations</em>
+<a class="jxr_linenumber" name="542" href="#542">542</a> <strong class="jxr_keyword">int</strong> movesWithinInstance = migrateSlaveAssignMapToNewInstances(slaveAssignmentMap, newInstances);
+<a class="jxr_linenumber" name="543" href="#543">543</a> <em class="jxr_comment">// System.out.println("local moves: "+ movesWithinInstance);</em>
+<a class="jxr_linenumber" name="544" href="#544">544</a> totalSlaveMoves += movesWithinInstance;
+<a class="jxr_linenumber" name="545" href="#545">545</a> }
+<a class="jxr_linenumber" name="546" href="#546">546</a> <em class="jxr_comment">// System.out.println("local slave moves total: "+ totalSlaveMoves);</em>
+<a class="jxr_linenumber" name="547" href="#547">547</a> <em class="jxr_comment">// calculate the master /slave assignment for the new added nodes</em>
+<a class="jxr_linenumber" name="548" href="#548">548</a>
+<a class="jxr_linenumber" name="549" href="#549">549</a> <em class="jxr_comment">// We already have the list of master partitions that will migrate to new batch of instances,</em>
+<a class="jxr_linenumber" name="550" href="#550">550</a> <em class="jxr_comment">// shuffle the partitions and assign them to new instances</em>
+<a class="jxr_linenumber" name="551" href="#551">551</a> Collections.shuffle(masterPartitionListToMove, <strong class="jxr_keyword">new</strong> Random(12345));
+<a class="jxr_linenumber" name="552" href="#552">552</a> <strong class="jxr_keyword">for</strong>(<strong class="jxr_keyword">int</strong> i = 0;i < newInstances.size(); i++)
+<a class="jxr_linenumber" name="553" href="#553">553</a> {
+<a class="jxr_linenumber" name="554" href="#554">554</a> String newInstance = newInstances.get(i);
+<a class="jxr_linenumber" name="555" href="#555">555</a> List<Integer> masterPartitionList = <strong class="jxr_keyword">new</strong> ArrayList<Integer>();
+<a class="jxr_linenumber" name="556" href="#556">556</a> <strong class="jxr_keyword">for</strong>(<strong class="jxr_keyword">int</strong> j = 0;j < masterPartitionListToMove.size(); j++)
+<a class="jxr_linenumber" name="557" href="#557">557</a> {
+<a class="jxr_linenumber" name="558" href="#558">558</a> <strong class="jxr_keyword">if</strong>(j % newInstances.size() == i)
+<a class="jxr_linenumber" name="559" href="#559">559</a> {
+<a class="jxr_linenumber" name="560" href="#560">560</a> masterPartitionList.add(masterPartitionListToMove.get(j));
+<a class="jxr_linenumber" name="561" href="#561">561</a> }
+<a class="jxr_linenumber" name="562" href="#562">562</a> }
+<a class="jxr_linenumber" name="563" href="#563">563</a>
+<a class="jxr_linenumber" name="564" href="#564">564</a> Map<String, List<Integer>> slavePartitionMap = <strong class="jxr_keyword">new</strong> TreeMap<String, List<Integer>>();
+<a class="jxr_linenumber" name="565" href="#565">565</a> <strong class="jxr_keyword">for</strong>(String oldInstance : oldInstances)
+<a class="jxr_linenumber" name="566" href="#566">566</a> {
+<a class="jxr_linenumber" name="567" href="#567">567</a> slavePartitionMap.put(oldInstance, <strong class="jxr_keyword">new</strong> ArrayList<Integer>());
+<a class="jxr_linenumber" name="568" href="#568">568</a> }
+<a class="jxr_linenumber" name="569" href="#569">569</a> <em class="jxr_comment">// Build the slave assignment map for the new instance, based on the saved information</em>
+<a class="jxr_linenumber" name="570" href="#570">570</a> <em class="jxr_comment">// about those slave partition locations in slavePartitionsToMoveMap</em>
+<a class="jxr_linenumber" name="571" href="#571">571</a> <strong class="jxr_keyword">for</strong>(Integer x : masterPartitionList)
+<a class="jxr_linenumber" name="572" href="#572">572</a> {
+<a class="jxr_linenumber" name="573" href="#573">573</a> <strong class="jxr_keyword">for</strong>(String oldInstance : slavePartitionsToMoveMap.keySet())
+<a class="jxr_linenumber" name="574" href="#574">574</a> {
+<a class="jxr_linenumber" name="575" href="#575">575</a> List<Integer> slaves = slavePartitionsToMoveMap.get(oldInstance);
+<a class="jxr_linenumber" name="576" href="#576">576</a> <strong class="jxr_keyword">if</strong>(slaves.contains(x))
+<a class="jxr_linenumber" name="577" href="#577">577</a> {
+<a class="jxr_linenumber" name="578" href="#578">578</a> slavePartitionMap.get(oldInstance).add(x);
+<a class="jxr_linenumber" name="579" href="#579">579</a> }
+<a class="jxr_linenumber" name="580" href="#580">580</a> }
+<a class="jxr_linenumber" name="581" href="#581">581</a> }
+<a class="jxr_linenumber" name="582" href="#582">582</a> <em class="jxr_comment">// add entry for other new instances into the slavePartitionMap</em>
+<a class="jxr_linenumber" name="583" href="#583">583</a> List<String> otherNewInstances = <strong class="jxr_keyword">new</strong> ArrayList<String>();
+<a class="jxr_linenumber" name="584" href="#584">584</a> <strong class="jxr_keyword">for</strong>(String instance : newInstances)
+<a class="jxr_linenumber" name="585" href="#585">585</a> {
+<a class="jxr_linenumber" name="586" href="#586">586</a> <strong class="jxr_keyword">if</strong>(!instance.equalsIgnoreCase(newInstance))
+<a class="jxr_linenumber" name="587" href="#587">587</a> {
+<a class="jxr_linenumber" name="588" href="#588">588</a> otherNewInstances.add(instance);
+<a class="jxr_linenumber" name="589" href="#589">589</a> }
+<a class="jxr_linenumber" name="590" href="#590">590</a> }
+<a class="jxr_linenumber" name="591" href="#591">591</a> <em class="jxr_comment">// Make sure that slave partitions are evenly distributed</em>
+<a class="jxr_linenumber" name="592" href="#592">592</a> migrateSlaveAssignMapToNewInstances(slavePartitionMap, otherNewInstances);
+<a class="jxr_linenumber" name="593" href="#593">593</a>
+<a class="jxr_linenumber" name="594" href="#594">594</a> <em class="jxr_comment">// Update the result in the result map. We can reuse the input previousIdealState map as</em>
+<a class="jxr_linenumber" name="595" href="#595">595</a> <em class="jxr_comment">// the result.</em>
+<a class="jxr_linenumber" name="596" href="#596">596</a> previousMasterAssignmentMap.put(newInstance, masterPartitionList);
+<a class="jxr_linenumber" name="597" href="#597">597</a> nodeSlaveAssignmentMap.put(newInstance, slavePartitionMap);
+<a class="jxr_linenumber" name="598" href="#598">598</a>
+<a class="jxr_linenumber" name="599" href="#599">599</a> }
+<a class="jxr_linenumber" name="600" href="#600">600</a> <em class="jxr_comment">/*</em>
+<a class="jxr_linenumber" name="601" href="#601">601</a> <em class="jxr_comment"> // Print content of the master/ slave assignment maps</em>
+<a class="jxr_linenumber" name="602" href="#602">602</a> <em class="jxr_comment"> for(String instanceName : previousMasterAssignmentMap.keySet())</em>
+<a class="jxr_linenumber" name="603" href="#603">603</a> <em class="jxr_comment"> {</em>
+<a class="jxr_linenumber" name="604" href="#604">604</a> <em class="jxr_comment"> System.out.println(instanceName+":");</em>
+<a class="jxr_linenumber" name="605" href="#605">605</a> <em class="jxr_comment"> for(Integer x : previousMasterAssignmentMap.get(instanceName))</em>
+<a class="jxr_linenumber" name="606" href="#606">606</a> <em class="jxr_comment"> {</em>
+<a class="jxr_linenumber" name="607" href="#607">607</a> <em class="jxr_comment"> System.out.print(x+" ");</em>
+<a class="jxr_linenumber" name="608" href="#608">608</a> <em class="jxr_comment"> }</em>
+<a class="jxr_linenumber" name="609" href="#609">609</a> <em class="jxr_comment"> System.out.println("\nmaster partition moved:");</em>
+<a class="jxr_linenumber" name="610" href="#610">610</a>
+<a class="jxr_linenumber" name="611" href="#611">611</a> <em class="jxr_comment"> System.out.println();</em>
+<a class="jxr_linenumber" name="612" href="#612">612</a> <em class="jxr_comment"> System.out.println("Slave assignment:");</em>
+<a class="jxr_linenumber" name="613" href="#613">613</a>
+<a class="jxr_linenumber" name="614" href="#614">614</a> <em class="jxr_comment"> Map<String, List<Integer>> slaveAssignmentMap = nodeSlaveAssignmentMap.get(instanceName);</em>
+<a class="jxr_linenumber" name="615" href="#615">615</a> <em class="jxr_comment"> for(String slaveName : slaveAssignmentMap.keySet())</em>
+<a class="jxr_linenumber" name="616" href="#616">616</a> <em class="jxr_comment"> {</em>
+<a class="jxr_linenumber" name="617" href="#617">617</a> <em class="jxr_comment"> System.out.print("\t" + slaveName +":\n\t" );</em>
+<a class="jxr_linenumber" name="618" href="#618">618</a> <em class="jxr_comment"> for(Integer x : slaveAssignmentMap.get(slaveName))</em>
+<a class="jxr_linenumber" name="619" href="#619">619</a> <em class="jxr_comment"> {</em>
+<a class="jxr_linenumber" name="620" href="#620">620</a> <em class="jxr_comment"> System.out.print(x + " ");</em>
+<a class="jxr_linenumber" name="621" href="#621">621</a> <em class="jxr_comment"> }</em>
+<a class="jxr_linenumber" name="622" href="#622">622</a> <em class="jxr_comment"> System.out.println("\n");</em>
+<a class="jxr_linenumber" name="623" href="#623">623</a> <em class="jxr_comment"> }</em>
+<a class="jxr_linenumber" name="624" href="#624">624</a> <em class="jxr_comment"> }</em>
+<a class="jxr_linenumber" name="625" href="#625">625</a>
+<a class="jxr_linenumber" name="626" href="#626">626</a> <em class="jxr_comment"> System.out.println("Master partitions migrated to new instances");</em>
+<a class="jxr_linenumber" name="627" href="#627">627</a> <em class="jxr_comment"> for(Integer x : masterPartitionListToMove)</em>
+<a class="jxr_linenumber" name="628" href="#628">628</a> <em class="jxr_comment"> {</em>
+<a class="jxr_linenumber" name="629" href="#629">629</a> <em class="jxr_comment"> System.out.print(x+" ");</em>
+<a class="jxr_linenumber" name="630" href="#630">630</a> <em class="jxr_comment"> }</em>
+<a class="jxr_linenumber" name="631" href="#631">631</a> <em class="jxr_comment"> System.out.println();</em>
+<a class="jxr_linenumber" name="632" href="#632">632</a>
+<a class="jxr_linenumber" name="633" href="#633">633</a> <em class="jxr_comment"> System.out.println("Slave partitions migrated to new instances");</em>
+<a class="jxr_linenumber" name="634" href="#634">634</a> <em class="jxr_comment"> for(String oldInstance : slavePartitionsToMoveMap.keySet())</em>
+<a class="jxr_linenumber" name="635" href="#635">635</a> <em class="jxr_comment"> {</em>
+<a class="jxr_linenumber" name="636" href="#636">636</a> <em class="jxr_comment"> System.out.print(oldInstance + ": ");</em>
+<a class="jxr_linenumber" name="637" href="#637">637</a> <em class="jxr_comment"> for(Integer x : slavePartitionsToMoveMap.get(oldInstance))</em>
+<a class="jxr_linenumber" name="638" href="#638">638</a> <em class="jxr_comment"> {</em>
+<a class="jxr_linenumber" name="639" href="#639">639</a> <em class="jxr_comment"> System.out.print(x+" ");</em>
+<a class="jxr_linenumber" name="640" href="#640">640</a> <em class="jxr_comment"> }</em>
+<a class="jxr_linenumber" name="641" href="#641">641</a> <em class="jxr_comment"> System.out.println();</em>
+<a class="jxr_linenumber" name="642" href="#642">642</a> <em class="jxr_comment"> }</em>
+<a class="jxr_linenumber" name="643" href="#643">643</a> <em class="jxr_comment"> */</em>
+<a class="jxr_linenumber" name="644" href="#644">644</a> <strong class="jxr_keyword">return</strong> previousIdealState;
+<a class="jxr_linenumber" name="645" href="#645">645</a> }
+<a class="jxr_linenumber" name="646" href="#646">646</a>
+<a class="jxr_linenumber" name="647" href="#647">647</a> <strong class="jxr_keyword">public</strong> <a href="../../../../org/apache/helix/ZNRecord.html">ZNRecord</a> calculateNextIdealState(List<String> newInstances, Map<String, Object> previousIdealState,
+<a class="jxr_linenumber" name="648" href="#648">648</a> String resourceName, String masterStateValue, String slaveStateValue)
+<a class="jxr_linenumber" name="649" href="#649">649</a> {
+<a class="jxr_linenumber" name="650" href="#650">650</a> <strong class="jxr_keyword">return</strong> convertToZNRecord(calculateNextIdealState(newInstances, previousIdealState), resourceName, masterStateValue, slaveStateValue);
+<a class="jxr_linenumber" name="651" href="#651">651</a> }
+<a class="jxr_linenumber" name="652" href="#652">652</a> <em class="jxr_javadoccomment">/**</em>
+<a class="jxr_linenumber" name="653" href="#653">653</a> <em class="jxr_javadoccomment"> * Given the list of master partition that will be migrated away from the storage instance,</em>
+<a class="jxr_linenumber" name="654" href="#654">654</a> <em class="jxr_javadoccomment"> * Remove their entries from the local instance slave assignment map.</em>
+<a class="jxr_linenumber" name="655" href="#655">655</a> <em class="jxr_javadoccomment"> *</em>
+<a class="jxr_linenumber" name="656" href="#656">656</a> <em class="jxr_javadoccomment"> * @param slaveAssignmentMap the local instance slave assignment map</em>
+<a class="jxr_linenumber" name="657" href="#657">657</a> <em class="jxr_javadoccomment"> * @param masterPartionsMoved the list of master partition ids that will be migrated away</em>
+<a class="jxr_linenumber" name="658" href="#658">658</a> <em class="jxr_javadoccomment"> * @param removedAssignmentMap keep track of the removed slave assignment info. The info can be</em>
+<a class="jxr_linenumber" name="659" href="#659">659</a> <em class="jxr_javadoccomment"> * used by new added storage nodes.</em>
+<a class="jxr_linenumber" name="660" href="#660">660</a> <em class="jxr_javadoccomment"> * */</em>
+<a class="jxr_linenumber" name="661" href="#661">661</a> <strong class="jxr_keyword">static</strong> <strong class="jxr_keyword">void</strong> removeFromSlaveAssignmentMap( Map<String, List<Integer>>slaveAssignmentMap, List<Integer> masterPartionsMoved, Map<String, List<Integer>> removedAssignmentMap)
+<a class="jxr_linenumber" name="662" href="#662">662</a> {
+<a class="jxr_linenumber" name="663" href="#663">663</a> <strong class="jxr_keyword">for</strong>(String instanceName : slaveAssignmentMap.keySet())
+<a class="jxr_linenumber" name="664" href="#664">664</a> {
+<a class="jxr_linenumber" name="665" href="#665">665</a> List<Integer> slaveAssignment = slaveAssignmentMap.get(instanceName);
+<a class="jxr_linenumber" name="666" href="#666">666</a> <strong class="jxr_keyword">for</strong>(Integer partitionId: masterPartionsMoved)
+<a class="jxr_linenumber" name="667" href="#667">667</a> {
+<a class="jxr_linenumber" name="668" href="#668">668</a> <strong class="jxr_keyword">if</strong>(slaveAssignment.contains(partitionId))
+<a class="jxr_linenumber" name="669" href="#669">669</a> {
+<a class="jxr_linenumber" name="670" href="#670">670</a> slaveAssignment.remove(partitionId);
+<a class="jxr_linenumber" name="671" href="#671">671</a> <strong class="jxr_keyword">if</strong>(!removedAssignmentMap.containsKey(instanceName))
+<a class="jxr_linenumber" name="672" href="#672">672</a> {
+<a class="jxr_linenumber" name="673" href="#673">673</a> removedAssignmentMap.put(instanceName, <strong class="jxr_keyword">new</strong> ArrayList<Integer>());
+<a class="jxr_linenumber" name="674" href="#674">674</a> }
+<a class="jxr_linenumber" name="675" href="#675">675</a> removedAssignmentMap.get(instanceName).add(partitionId);
+<a class="jxr_linenumber" name="676" href="#676">676</a> }
+<a class="jxr_linenumber" name="677" href="#677">677</a> }
+<a class="jxr_linenumber" name="678" href="#678">678</a> }
+<a class="jxr_linenumber" name="679" href="#679">679</a> }
+<a class="jxr_linenumber" name="680" href="#680">680</a>
+<a class="jxr_linenumber" name="681" href="#681">681</a> <em class="jxr_javadoccomment">/**</em>
+<a class="jxr_linenumber" name="682" href="#682">682</a> <em class="jxr_javadoccomment"> * Since some new storage instances are added, each existing storage instance should migrate some</em>
+<a class="jxr_linenumber" name="683" href="#683">683</a> <em class="jxr_javadoccomment"> * slave partitions to the new added instances.</em>
+<a class="jxr_linenumber" name="684" href="#684">684</a> <em class="jxr_javadoccomment"> *</em>
+<a class="jxr_linenumber" name="685" href="#685">685</a> <em class="jxr_javadoccomment"> * The algorithm keeps moving one partition to from the instance that hosts most slave partitions</em>
+<a class="jxr_linenumber" name="686" href="#686">686</a> <em class="jxr_javadoccomment"> * to the instance that hosts least number of partitions, until max-min <= 1.</em>
+<a class="jxr_linenumber" name="687" href="#687">687</a> <em class="jxr_javadoccomment"> *</em>
+<a class="jxr_linenumber" name="688" href="#688">688</a> <em class="jxr_javadoccomment"> * In this way we can guarantee that all instances hosts almost same number of slave partitions, also</em>
+<a class="jxr_linenumber" name="689" href="#689">689</a> <em class="jxr_javadoccomment"> * slave partitions are evenly distributed.</em>
+<a class="jxr_linenumber" name="690" href="#690">690</a> <em class="jxr_javadoccomment"> *</em>
+<a class="jxr_linenumber" name="691" href="#691">691</a> <em class="jxr_javadoccomment"> * @param slaveAssignmentMap the local instance slave assignment map</em>
+<a class="jxr_linenumber" name="692" href="#692">692</a> <em class="jxr_javadoccomment"> * @param masterPartionsMoved the list of master partition ids that will be migrated away</em>
+<a class="jxr_linenumber" name="693" href="#693">693</a> <em class="jxr_javadoccomment"> * @param removedAssignmentMap keep track of the removed slave assignment info. The info can be</em>
+<a class="jxr_linenumber" name="694" href="#694">694</a> <em class="jxr_javadoccomment"> * used by new added storage nodes.</em>
+<a class="jxr_linenumber" name="695" href="#695">695</a> <em class="jxr_javadoccomment"> * */</em>
+<a class="jxr_linenumber" name="696" href="#696">696</a> <strong class="jxr_keyword">static</strong> <strong class="jxr_keyword">int</strong> migrateSlaveAssignMapToNewInstances(Map<String, List<Integer>> nodeSlaveAssignmentMap, List<String> newInstances)
+<a class="jxr_linenumber" name="697" href="#697">697</a> {
+<a class="jxr_linenumber" name="698" href="#698">698</a> <strong class="jxr_keyword">int</strong> moves = 0;
+<a class="jxr_linenumber" name="699" href="#699">699</a> <strong class="jxr_keyword">boolean</strong> done = false;
+<a class="jxr_linenumber" name="700" href="#700">700</a> <strong class="jxr_keyword">for</strong>(String newInstance : newInstances)
+<a class="jxr_linenumber" name="701" href="#701">701</a> {
+<a class="jxr_linenumber" name="702" href="#702">702</a> nodeSlaveAssignmentMap.put(newInstance, <strong class="jxr_keyword">new</strong> ArrayList<Integer>());
+<a class="jxr_linenumber" name="703" href="#703">703</a> }
+<a class="jxr_linenumber" name="704" href="#704">704</a> <strong class="jxr_keyword">while</strong>(!done)
+<a class="jxr_linenumber" name="705" href="#705">705</a> {
+<a class="jxr_linenumber" name="706" href="#706">706</a> List<Integer> maxAssignment = <strong class="jxr_keyword">null</strong>, minAssignment = <strong class="jxr_keyword">null</strong>;
+<a class="jxr_linenumber" name="707" href="#707">707</a> <strong class="jxr_keyword">int</strong> minCount = Integer.MAX_VALUE, maxCount = Integer.MIN_VALUE;
[... 89 lines stripped ...]