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Posted to commits@hbase.apache.org by mi...@apache.org on 2016/02/11 18:34:33 UTC
[27/51] [partial] hbase-site git commit: Published site at
29a192ef3cbe3b9cc12a6ee38f39e1199ac9790f.
http://git-wip-us.apache.org/repos/asf/hbase-site/blob/8bb348c6/devapidocs/src-html/org/apache/hadoop/hbase/master/balancer/SimpleLoadBalancer.BalanceInfo.html
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diff --git a/devapidocs/src-html/org/apache/hadoop/hbase/master/balancer/SimpleLoadBalancer.BalanceInfo.html b/devapidocs/src-html/org/apache/hadoop/hbase/master/balancer/SimpleLoadBalancer.BalanceInfo.html
index 4345bcc..a682fea 100644
--- a/devapidocs/src-html/org/apache/hadoop/hbase/master/balancer/SimpleLoadBalancer.BalanceInfo.html
+++ b/devapidocs/src-html/org/apache/hadoop/hbase/master/balancer/SimpleLoadBalancer.BalanceInfo.html
@@ -54,402 +54,398 @@
<span class="sourceLineNo">046</span> * <p>Cluster-wide load balancing will occur only when there are no regions in<a name="line.46"></a>
<span class="sourceLineNo">047</span> * transition and according to a fixed period of a time using {@link #balanceCluster(Map)}.<a name="line.47"></a>
<span class="sourceLineNo">048</span> *<a name="line.48"></a>
-<span class="sourceLineNo">049</span> * <p>Inline region placement with {@link #immediateAssignment} can be used when<a name="line.49"></a>
-<span class="sourceLineNo">050</span> * the Master needs to handle closed regions that it currently does not have<a name="line.50"></a>
-<span class="sourceLineNo">051</span> * a destination set for. This can happen during master failover.<a name="line.51"></a>
-<span class="sourceLineNo">052</span> *<a name="line.52"></a>
-<span class="sourceLineNo">053</span> * <p>On cluster startup, bulk assignment can be used to determine<a name="line.53"></a>
-<span class="sourceLineNo">054</span> * locations for all Regions in a cluster.<a name="line.54"></a>
-<span class="sourceLineNo">055</span> *<a name="line.55"></a>
-<span class="sourceLineNo">056</span> * <p>This classes produces plans for the <a name="line.56"></a>
-<span class="sourceLineNo">057</span> * {@link org.apache.hadoop.hbase.master.AssignmentManager} to execute.<a name="line.57"></a>
-<span class="sourceLineNo">058</span> */<a name="line.58"></a>
-<span class="sourceLineNo">059</span>@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.CONFIG)<a name="line.59"></a>
-<span class="sourceLineNo">060</span>public class SimpleLoadBalancer extends BaseLoadBalancer {<a name="line.60"></a>
-<span class="sourceLineNo">061</span> private static final Log LOG = LogFactory.getLog(SimpleLoadBalancer.class);<a name="line.61"></a>
-<span class="sourceLineNo">062</span> private static final Random RANDOM = new Random(System.currentTimeMillis());<a name="line.62"></a>
+<span class="sourceLineNo">049</span> * <p>On cluster startup, bulk assignment can be used to determine<a name="line.49"></a>
+<span class="sourceLineNo">050</span> * locations for all Regions in a cluster.<a name="line.50"></a>
+<span class="sourceLineNo">051</span> *<a name="line.51"></a>
+<span class="sourceLineNo">052</span> * <p>This classes produces plans for the<a name="line.52"></a>
+<span class="sourceLineNo">053</span> * {@link org.apache.hadoop.hbase.master.AssignmentManager} to execute.<a name="line.53"></a>
+<span class="sourceLineNo">054</span> */<a name="line.54"></a>
+<span class="sourceLineNo">055</span>@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.CONFIG)<a name="line.55"></a>
+<span class="sourceLineNo">056</span>public class SimpleLoadBalancer extends BaseLoadBalancer {<a name="line.56"></a>
+<span class="sourceLineNo">057</span> private static final Log LOG = LogFactory.getLog(SimpleLoadBalancer.class);<a name="line.57"></a>
+<span class="sourceLineNo">058</span> private static final Random RANDOM = new Random(System.currentTimeMillis());<a name="line.58"></a>
+<span class="sourceLineNo">059</span><a name="line.59"></a>
+<span class="sourceLineNo">060</span> private RegionInfoComparator riComparator = new RegionInfoComparator();<a name="line.60"></a>
+<span class="sourceLineNo">061</span> private RegionPlan.RegionPlanComparator rpComparator = new RegionPlan.RegionPlanComparator();<a name="line.61"></a>
+<span class="sourceLineNo">062</span><a name="line.62"></a>
<span class="sourceLineNo">063</span><a name="line.63"></a>
-<span class="sourceLineNo">064</span> private RegionInfoComparator riComparator = new RegionInfoComparator();<a name="line.64"></a>
-<span class="sourceLineNo">065</span> private RegionPlan.RegionPlanComparator rpComparator = new RegionPlan.RegionPlanComparator();<a name="line.65"></a>
-<span class="sourceLineNo">066</span><a name="line.66"></a>
-<span class="sourceLineNo">067</span><a name="line.67"></a>
-<span class="sourceLineNo">068</span> /**<a name="line.68"></a>
-<span class="sourceLineNo">069</span> * Stores additional per-server information about the regions added/removed<a name="line.69"></a>
-<span class="sourceLineNo">070</span> * during the run of the balancing algorithm.<a name="line.70"></a>
-<span class="sourceLineNo">071</span> *<a name="line.71"></a>
-<span class="sourceLineNo">072</span> * For servers that shed regions, we need to track which regions we have already<a name="line.72"></a>
-<span class="sourceLineNo">073</span> * shed. <b>nextRegionForUnload</b> contains the index in the list of regions on<a name="line.73"></a>
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-<span class="sourceLineNo">081</span> public BalanceInfo(int nextRegionForUnload, int numRegionsAdded) {<a name="line.81"></a>
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+<span class="sourceLineNo">066</span> * during the run of the balancing algorithm.<a name="line.66"></a>
+<span class="sourceLineNo">067</span> *<a name="line.67"></a>
+<span class="sourceLineNo">068</span> * For servers that shed regions, we need to track which regions we have already<a name="line.68"></a>
+<span class="sourceLineNo">069</span> * shed. <b>nextRegionForUnload</b> contains the index in the list of regions on<a name="line.69"></a>
+<span class="sourceLineNo">070</span> * the server that is the next to be shed.<a name="line.70"></a>
+<span class="sourceLineNo">071</span> */<a name="line.71"></a>
+<span class="sourceLineNo">072</span> static class BalanceInfo {<a name="line.72"></a>
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+<span class="sourceLineNo">076</span><a name="line.76"></a>
+<span class="sourceLineNo">077</span> public BalanceInfo(int nextRegionForUnload, int numRegionsAdded) {<a name="line.77"></a>
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+<span class="sourceLineNo">079</span> this.numRegionsAdded = numRegionsAdded;<a name="line.79"></a>
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<span class="sourceLineNo">084</span> }<a name="line.84"></a>
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-<span class="sourceLineNo">087</span> return nextRegionForUnload;<a name="line.87"></a>
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-<span class="sourceLineNo">091</span> return numRegionsAdded;<a name="line.91"></a>
+<span class="sourceLineNo">090</span> void setNumRegionsAdded(int numAdded) {<a name="line.90"></a>
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<span class="sourceLineNo">092</span> }<a name="line.92"></a>
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-<span class="sourceLineNo">094</span> void setNumRegionsAdded(int numAdded) {<a name="line.94"></a>
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-<span class="sourceLineNo">099</span> /**<a name="line.99"></a>
-<span class="sourceLineNo">100</span> * Generate a global load balancing plan according to the specified map of<a name="line.100"></a>
-<span class="sourceLineNo">101</span> * server information to the most loaded regions of each server.<a name="line.101"></a>
-<span class="sourceLineNo">102</span> *<a name="line.102"></a>
-<span class="sourceLineNo">103</span> * The load balancing invariant is that all servers are within 1 region of the<a name="line.103"></a>
-<span class="sourceLineNo">104</span> * average number of regions per server. If the average is an integer number,<a name="line.104"></a>
-<span class="sourceLineNo">105</span> * all servers will be balanced to the average. Otherwise, all servers will<a name="line.105"></a>
-<span class="sourceLineNo">106</span> * have either floor(average) or ceiling(average) regions.<a name="line.106"></a>
-<span class="sourceLineNo">107</span> *<a name="line.107"></a>
-<span class="sourceLineNo">108</span> * HBASE-3609 Modeled regionsToMove using Guava's MinMaxPriorityQueue so that<a name="line.108"></a>
-<span class="sourceLineNo">109</span> * we can fetch from both ends of the queue.<a name="line.109"></a>
-<span class="sourceLineNo">110</span> * At the beginning, we check whether there was empty region server<a name="line.110"></a>
-<span class="sourceLineNo">111</span> * just discovered by Master. If so, we alternately choose new / old<a name="line.111"></a>
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-<span class="sourceLineNo">113</span> * avoids clustering young regions on the newly discovered region server.<a name="line.113"></a>
-<span class="sourceLineNo">114</span> * Otherwise, we choose new regions from head of regionsToMove.<a name="line.114"></a>
-<span class="sourceLineNo">115</span> *<a name="line.115"></a>
-<span class="sourceLineNo">116</span> * Another improvement from HBASE-3609 is that we assign regions from<a name="line.116"></a>
-<span class="sourceLineNo">117</span> * regionsToMove to underloaded servers in round-robin fashion.<a name="line.117"></a>
-<span class="sourceLineNo">118</span> * Previously one underloaded server would be filled before we move onto<a name="line.118"></a>
-<span class="sourceLineNo">119</span> * the next underloaded server, leading to clustering of young regions.<a name="line.119"></a>
-<span class="sourceLineNo">120</span> *<a name="line.120"></a>
-<span class="sourceLineNo">121</span> * Finally, we randomly shuffle underloaded servers so that they receive<a name="line.121"></a>
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-<span class="sourceLineNo">123</span> *<a name="line.123"></a>
-<span class="sourceLineNo">124</span> * The algorithm is currently implemented as such:<a name="line.124"></a>
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+<span class="sourceLineNo">095</span> /**<a name="line.95"></a>
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+<span class="sourceLineNo">097</span> * server information to the most loaded regions of each server.<a name="line.97"></a>
+<span class="sourceLineNo">098</span> *<a name="line.98"></a>
+<span class="sourceLineNo">099</span> * The load balancing invariant is that all servers are within 1 region of the<a name="line.99"></a>
+<span class="sourceLineNo">100</span> * average number of regions per server. If the average is an integer number,<a name="line.100"></a>
+<span class="sourceLineNo">101</span> * all servers will be balanced to the average. Otherwise, all servers will<a name="line.101"></a>
+<span class="sourceLineNo">102</span> * have either floor(average) or ceiling(average) regions.<a name="line.102"></a>
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+<span class="sourceLineNo">105</span> * we can fetch from both ends of the queue.<a name="line.105"></a>
+<span class="sourceLineNo">106</span> * At the beginning, we check whether there was empty region server<a name="line.106"></a>
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+<span class="sourceLineNo">111</span> *<a name="line.111"></a>
+<span class="sourceLineNo">112</span> * Another improvement from HBASE-3609 is that we assign regions from<a name="line.112"></a>
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+<span class="sourceLineNo">114</span> * Previously one underloaded server would be filled before we move onto<a name="line.114"></a>
+<span class="sourceLineNo">115</span> * the next underloaded server, leading to clustering of young regions.<a name="line.115"></a>
+<span class="sourceLineNo">116</span> *<a name="line.116"></a>
+<span class="sourceLineNo">117</span> * Finally, we randomly shuffle underloaded servers so that they receive<a name="line.117"></a>
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+<span class="sourceLineNo">119</span> *<a name="line.119"></a>
+<span class="sourceLineNo">120</span> * The algorithm is currently implemented as such:<a name="line.120"></a>
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+<span class="sourceLineNo">122</span> * <ol><a name="line.122"></a>
+<span class="sourceLineNo">123</span> * <li>Determine the two valid numbers of regions each server should have,<a name="line.123"></a>
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<span class="sourceLineNo">125</span> *<a name="line.125"></a>
-<span class="sourceLineNo">126</span> * <ol><a name="line.126"></a>
-<span class="sourceLineNo">127</span> * <li>Determine the two valid numbers of regions each server should have,<a name="line.127"></a>
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-<span class="sourceLineNo">133</span> * <p><a name="line.133"></a>
-<span class="sourceLineNo">134</span> * Order the regions to move from most recent to least.<a name="line.134"></a>
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+<span class="sourceLineNo">129</span> * <p><a name="line.129"></a>
+<span class="sourceLineNo">130</span> * Order the regions to move from most recent to least.<a name="line.130"></a>
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-<span class="sourceLineNo">143</span> * end up with a number of regions required to do so, <b>neededRegions</b>.<a name="line.143"></a>
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+<span class="sourceLineNo">141</span> * It is also possible that we were able to fill each underloaded but ended<a name="line.141"></a>
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-<span class="sourceLineNo">160</span> * Iterate the least loaded servers filling each to <b>MIN</b>.<a name="line.160"></a>
+<span class="sourceLineNo">158</span> * <li>If we still have more regions that need assignment, again iterate the<a name="line.158"></a>
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+<span class="sourceLineNo">390</span> server.getKey().getServerName(), regionsToReturn);<a name="line.390"></a>
+<span class="sourceLineNo">391</span> if (regionsToMove.isEmpty()) {<a name="line.391"></a>
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+<span class="sourceLineNo">394</span> }<a name="line.394"></a>
+<span class="sourceLineNo">395</span> }<a name="line.395"></a>
+<span class="sourceLineNo">396</span><a name="line.396"></a>
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+<span class="sourceLineNo">400</span> // Emit data so can diagnose how balancer went astray.<a name="line.400"></a>
+<span class="sourceLineNo">401</span> LOG.warn("regionsToMove=" + totalNumMoved +<a name="line.401"></a>
+<span class="sourceLineNo">402</span> ", numServers=" + numServers + ", serversOverloaded=" + serversOverloaded +<a name="line.402"></a>
+<span class="sourceLineNo">403</span> ", serversUnderloaded=" + serversUnderloaded);<a name="line.403"></a>
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+<span class="sourceLineNo">407</span> sb.append(e.getKey().toString());<a name="line.407"></a>
+<span class="sourceLineNo">408</span> sb.append(" ");<a name="line.408"></a>
+<span class="sourceLineNo">409</span> sb.append(e.getValue().size());<a name="line.409"></a>
+<span class="sourceLineNo">410</span> }<a name="line.410"></a>
+<span class="sourceLineNo">411</span> LOG.warn("Input " + sb.toString());<a name="line.411"></a>
+<span class="sourceLineNo">412</span> }<a name="line.412"></a>
+<span class="sourceLineNo">413</span><a name="line.413"></a>
+<span class="sourceLineNo">414</span> // All done!<a name="line.414"></a>
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+<span class="sourceLineNo">416</span> "Moving " + totalNumMoved + " regions off of " +<a name="line.416"></a>
+<span class="sourceLineNo">417</span> serversOverloaded + " overloaded servers onto " +<a name="line.417"></a>
+<span class="sourceLineNo">418</span> serversUnderloaded + " less loaded servers");<a name="line.418"></a>
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+<span class="sourceLineNo">422</span><a name="line.422"></a>
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+<span class="sourceLineNo">428</span> RegionPlan rp = null;<a name="line.428"></a>
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+<span class="sourceLineNo">434</span><a name="line.434"></a>
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+<span class="sourceLineNo">439</span> }<a name="line.439"></a>
+<span class="sourceLineNo">440</span>}<a name="line.440"></a>