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<pre><span class="sourceLineNo">001</span>/*<a name="line.1"></a>
<span class="sourceLineNo">002</span> * Licensed to the Apache Software Foundation (ASF) under one<a name="line.2"></a>
<span class="sourceLineNo">003</span> * or more contributor license agreements. See the NOTICE file<a name="line.3"></a>
<span class="sourceLineNo">004</span> * distributed with this work for additional information<a name="line.4"></a>
<span class="sourceLineNo">005</span> * regarding copyright ownership. The ASF licenses this file<a name="line.5"></a>
<span class="sourceLineNo">006</span> * to you under the Apache License, Version 2.0 (the<a name="line.6"></a>
<span class="sourceLineNo">007</span> * "License"); you may not use this file except in compliance<a name="line.7"></a>
<span class="sourceLineNo">008</span> * with the License. You may obtain a copy of the License at<a name="line.8"></a>
<span class="sourceLineNo">009</span> *<a name="line.9"></a>
<span class="sourceLineNo">010</span> * http://www.apache.org/licenses/LICENSE-2.0<a name="line.10"></a>
<span class="sourceLineNo">011</span> *<a name="line.11"></a>
<span class="sourceLineNo">012</span> * Unless required by applicable law or agreed to in writing, software<a name="line.12"></a>
<span class="sourceLineNo">013</span> * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.13"></a>
<span class="sourceLineNo">014</span> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.14"></a>
<span class="sourceLineNo">015</span> * See the License for the specific language governing permissions and<a name="line.15"></a>
<span class="sourceLineNo">016</span> * limitations under the License.<a name="line.16"></a>
<span class="sourceLineNo">017</span> */<a name="line.17"></a>
<span class="sourceLineNo">018</span>package org.apache.hadoop.hbase.util;<a name="line.18"></a>
<span class="sourceLineNo">019</span><a name="line.19"></a>
<span class="sourceLineNo">020</span>import java.lang.management.GarbageCollectorMXBean;<a name="line.20"></a>
<span class="sourceLineNo">021</span>import java.lang.management.ManagementFactory;<a name="line.21"></a>
<span class="sourceLineNo">022</span>import java.util.List;<a name="line.22"></a>
<span class="sourceLineNo">023</span>import java.util.Map;<a name="line.23"></a>
<span class="sourceLineNo">024</span>import java.util.Set;<a name="line.24"></a>
<span class="sourceLineNo">025</span>import java.util.concurrent.TimeUnit;<a name="line.25"></a>
<span class="sourceLineNo">026</span>import org.apache.hadoop.conf.Configuration;<a name="line.26"></a>
<span class="sourceLineNo">027</span>import org.apache.hadoop.hbase.metrics.JvmPauseMonitorSource;<a name="line.27"></a>
<span class="sourceLineNo">028</span>import org.apache.yetus.audience.InterfaceAudience;<a name="line.28"></a>
<span class="sourceLineNo">029</span>import org.slf4j.Logger;<a name="line.29"></a>
<span class="sourceLineNo">030</span>import org.slf4j.LoggerFactory;<a name="line.30"></a>
<span class="sourceLineNo">031</span><a name="line.31"></a>
<span class="sourceLineNo">032</span>import org.apache.hbase.thirdparty.com.google.common.base.Joiner;<a name="line.32"></a>
<span class="sourceLineNo">033</span>import org.apache.hbase.thirdparty.com.google.common.base.Preconditions;<a name="line.33"></a>
<span class="sourceLineNo">034</span>import org.apache.hbase.thirdparty.com.google.common.base.Stopwatch;<a name="line.34"></a>
<span class="sourceLineNo">035</span>import org.apache.hbase.thirdparty.com.google.common.collect.Lists;<a name="line.35"></a>
<span class="sourceLineNo">036</span>import org.apache.hbase.thirdparty.com.google.common.collect.Maps;<a name="line.36"></a>
<span class="sourceLineNo">037</span>import org.apache.hbase.thirdparty.com.google.common.collect.Sets;<a name="line.37"></a>
<span class="sourceLineNo">038</span><a name="line.38"></a>
<span class="sourceLineNo">039</span>/**<a name="line.39"></a>
<span class="sourceLineNo">040</span> * Class which sets up a simple thread which runs in a loop sleeping for a short interval of time.<a name="line.40"></a>
<span class="sourceLineNo">041</span> * If the sleep takes significantly longer than its target time, it implies that the JVM or host<a name="line.41"></a>
<span class="sourceLineNo">042</span> * machine has paused processing, which may cause other problems. If such a pause is detected, the<a name="line.42"></a>
<span class="sourceLineNo">043</span> * thread logs a message. The original JvmPauseMonitor is:<a name="line.43"></a>
<span class="sourceLineNo">044</span> * ${hadoop-common-project}/hadoop-common/src/main/java/org/apache/hadoop/util/ JvmPauseMonitor.java<a name="line.44"></a>
<span class="sourceLineNo">045</span> * r1503806 | cmccabe | 2013-07-17 01:48:24 +0800 (Wed, 17 Jul 2013) | 1 line HADOOP-9618. thread<a name="line.45"></a>
<span class="sourceLineNo">046</span> * which detects GC pauses(Todd Lipcon)<a name="line.46"></a>
<span class="sourceLineNo">047</span> */<a name="line.47"></a>
<span class="sourceLineNo">048</span>@InterfaceAudience.Private<a name="line.48"></a>
<span class="sourceLineNo">049</span>public class JvmPauseMonitor {<a name="line.49"></a>
<span class="sourceLineNo">050</span> private static final Logger LOG = LoggerFactory.getLogger(JvmPauseMonitor.class);<a name="line.50"></a>
<span class="sourceLineNo">051</span><a name="line.51"></a>
<span class="sourceLineNo">052</span> /** The target sleep time */<a name="line.52"></a>
<span class="sourceLineNo">053</span> private static final long SLEEP_INTERVAL_MS = 500;<a name="line.53"></a>
<span class="sourceLineNo">054</span><a name="line.54"></a>
<span class="sourceLineNo">055</span> /** log WARN if we detect a pause longer than this threshold */<a name="line.55"></a>
<span class="sourceLineNo">056</span> private final long warnThresholdMs;<a name="line.56"></a>
<span class="sourceLineNo">057</span> public static final String WARN_THRESHOLD_KEY = "jvm.pause.warn-threshold.ms";<a name="line.57"></a>
<span class="sourceLineNo">058</span> private static final long WARN_THRESHOLD_DEFAULT = 10000;<a name="line.58"></a>
<span class="sourceLineNo">059</span><a name="line.59"></a>
<span class="sourceLineNo">060</span> /** log INFO if we detect a pause longer than this threshold */<a name="line.60"></a>
<span class="sourceLineNo">061</span> private final long infoThresholdMs;<a name="line.61"></a>
<span class="sourceLineNo">062</span> public static final String INFO_THRESHOLD_KEY = "jvm.pause.info-threshold.ms";<a name="line.62"></a>
<span class="sourceLineNo">063</span> private static final long INFO_THRESHOLD_DEFAULT = 1000;<a name="line.63"></a>
<span class="sourceLineNo">064</span><a name="line.64"></a>
<span class="sourceLineNo">065</span> private Thread monitorThread;<a name="line.65"></a>
<span class="sourceLineNo">066</span> private volatile boolean shouldRun = true;<a name="line.66"></a>
<span class="sourceLineNo">067</span> private JvmPauseMonitorSource metricsSource;<a name="line.67"></a>
<span class="sourceLineNo">068</span><a name="line.68"></a>
<span class="sourceLineNo">069</span> public JvmPauseMonitor(Configuration conf) {<a name="line.69"></a>
<span class="sourceLineNo">070</span> this(conf, null);<a name="line.70"></a>
<span class="sourceLineNo">071</span> }<a name="line.71"></a>
<span class="sourceLineNo">072</span><a name="line.72"></a>
<span class="sourceLineNo">073</span> public JvmPauseMonitor(Configuration conf, JvmPauseMonitorSource metricsSource) {<a name="line.73"></a>
<span class="sourceLineNo">074</span> this.warnThresholdMs = conf.getLong(WARN_THRESHOLD_KEY, WARN_THRESHOLD_DEFAULT);<a name="line.74"></a>
<span class="sourceLineNo">075</span> this.infoThresholdMs = conf.getLong(INFO_THRESHOLD_KEY, INFO_THRESHOLD_DEFAULT);<a name="line.75"></a>
<span class="sourceLineNo">076</span> this.metricsSource = metricsSource;<a name="line.76"></a>
<span class="sourceLineNo">077</span> }<a name="line.77"></a>
<span class="sourceLineNo">078</span><a name="line.78"></a>
<span class="sourceLineNo">079</span> public void start() {<a name="line.79"></a>
<span class="sourceLineNo">080</span> Preconditions.checkState(monitorThread == null, "Already started");<a name="line.80"></a>
<span class="sourceLineNo">081</span> monitorThread = new Thread(new Monitor(), "JvmPauseMonitor");<a name="line.81"></a>
<span class="sourceLineNo">082</span> monitorThread.setDaemon(true);<a name="line.82"></a>
<span class="sourceLineNo">083</span> monitorThread.start();<a name="line.83"></a>
<span class="sourceLineNo">084</span> }<a name="line.84"></a>
<span class="sourceLineNo">085</span><a name="line.85"></a>
<span class="sourceLineNo">086</span> public void stop() {<a name="line.86"></a>
<span class="sourceLineNo">087</span> shouldRun = false;<a name="line.87"></a>
<span class="sourceLineNo">088</span> monitorThread.interrupt();<a name="line.88"></a>
<span class="sourceLineNo">089</span> try {<a name="line.89"></a>
<span class="sourceLineNo">090</span> monitorThread.join();<a name="line.90"></a>
<span class="sourceLineNo">091</span> } catch (InterruptedException e) {<a name="line.91"></a>
<span class="sourceLineNo">092</span> Thread.currentThread().interrupt();<a name="line.92"></a>
<span class="sourceLineNo">093</span> }<a name="line.93"></a>
<span class="sourceLineNo">094</span> }<a name="line.94"></a>
<span class="sourceLineNo">095</span><a name="line.95"></a>
<span class="sourceLineNo">096</span> private String formatMessage(long extraSleepTime, List&lt;String&gt; gcDiffs) {<a name="line.96"></a>
<span class="sourceLineNo">097</span> String ret = "Detected pause in JVM or host machine (eg GC): " + "pause of approximately "<a name="line.97"></a>
<span class="sourceLineNo">098</span> + extraSleepTime + "ms\n";<a name="line.98"></a>
<span class="sourceLineNo">099</span> if (gcDiffs.isEmpty()) {<a name="line.99"></a>
<span class="sourceLineNo">100</span> ret += "No GCs detected";<a name="line.100"></a>
<span class="sourceLineNo">101</span> } else {<a name="line.101"></a>
<span class="sourceLineNo">102</span> ret += Joiner.on("\n").join(gcDiffs);<a name="line.102"></a>
<span class="sourceLineNo">103</span> }<a name="line.103"></a>
<span class="sourceLineNo">104</span> return ret;<a name="line.104"></a>
<span class="sourceLineNo">105</span> }<a name="line.105"></a>
<span class="sourceLineNo">106</span><a name="line.106"></a>
<span class="sourceLineNo">107</span> private Map&lt;String, GcTimes&gt; getGcTimes() {<a name="line.107"></a>
<span class="sourceLineNo">108</span> Map&lt;String, GcTimes&gt; map = Maps.newHashMap();<a name="line.108"></a>
<span class="sourceLineNo">109</span> List&lt;GarbageCollectorMXBean&gt; gcBeans = ManagementFactory.getGarbageCollectorMXBeans();<a name="line.109"></a>
<span class="sourceLineNo">110</span> for (GarbageCollectorMXBean gcBean : gcBeans) {<a name="line.110"></a>
<span class="sourceLineNo">111</span> map.put(gcBean.getName(), new GcTimes(gcBean));<a name="line.111"></a>
<span class="sourceLineNo">112</span> }<a name="line.112"></a>
<span class="sourceLineNo">113</span> return map;<a name="line.113"></a>
<span class="sourceLineNo">114</span> }<a name="line.114"></a>
<span class="sourceLineNo">115</span><a name="line.115"></a>
<span class="sourceLineNo">116</span> private static class GcTimes {<a name="line.116"></a>
<span class="sourceLineNo">117</span> private GcTimes(GarbageCollectorMXBean gcBean) {<a name="line.117"></a>
<span class="sourceLineNo">118</span> gcCount = gcBean.getCollectionCount();<a name="line.118"></a>
<span class="sourceLineNo">119</span> gcTimeMillis = gcBean.getCollectionTime();<a name="line.119"></a>
<span class="sourceLineNo">120</span> }<a name="line.120"></a>
<span class="sourceLineNo">121</span><a name="line.121"></a>
<span class="sourceLineNo">122</span> private GcTimes(long count, long time) {<a name="line.122"></a>
<span class="sourceLineNo">123</span> this.gcCount = count;<a name="line.123"></a>
<span class="sourceLineNo">124</span> this.gcTimeMillis = time;<a name="line.124"></a>
<span class="sourceLineNo">125</span> }<a name="line.125"></a>
<span class="sourceLineNo">126</span><a name="line.126"></a>
<span class="sourceLineNo">127</span> private GcTimes subtract(GcTimes other) {<a name="line.127"></a>
<span class="sourceLineNo">128</span> return new GcTimes(this.gcCount - other.gcCount, this.gcTimeMillis - other.gcTimeMillis);<a name="line.128"></a>
<span class="sourceLineNo">129</span> }<a name="line.129"></a>
<span class="sourceLineNo">130</span><a name="line.130"></a>
<span class="sourceLineNo">131</span> @Override<a name="line.131"></a>
<span class="sourceLineNo">132</span> public String toString() {<a name="line.132"></a>
<span class="sourceLineNo">133</span> return "count=" + gcCount + " time=" + gcTimeMillis + "ms";<a name="line.133"></a>
<span class="sourceLineNo">134</span> }<a name="line.134"></a>
<span class="sourceLineNo">135</span><a name="line.135"></a>
<span class="sourceLineNo">136</span> private long gcCount;<a name="line.136"></a>
<span class="sourceLineNo">137</span> private long gcTimeMillis;<a name="line.137"></a>
<span class="sourceLineNo">138</span> }<a name="line.138"></a>
<span class="sourceLineNo">139</span><a name="line.139"></a>
<span class="sourceLineNo">140</span> private class Monitor implements Runnable {<a name="line.140"></a>
<span class="sourceLineNo">141</span> @Override<a name="line.141"></a>
<span class="sourceLineNo">142</span> public void run() {<a name="line.142"></a>
<span class="sourceLineNo">143</span> Stopwatch sw = Stopwatch.createUnstarted();<a name="line.143"></a>
<span class="sourceLineNo">144</span> Map&lt;String, GcTimes&gt; gcTimesBeforeSleep = getGcTimes();<a name="line.144"></a>
<span class="sourceLineNo">145</span> while (shouldRun) {<a name="line.145"></a>
<span class="sourceLineNo">146</span> sw.reset().start();<a name="line.146"></a>
<span class="sourceLineNo">147</span> try {<a name="line.147"></a>
<span class="sourceLineNo">148</span> Thread.sleep(SLEEP_INTERVAL_MS);<a name="line.148"></a>
<span class="sourceLineNo">149</span> } catch (InterruptedException ie) {<a name="line.149"></a>
<span class="sourceLineNo">150</span> return;<a name="line.150"></a>
<span class="sourceLineNo">151</span> }<a name="line.151"></a>
<span class="sourceLineNo">152</span><a name="line.152"></a>
<span class="sourceLineNo">153</span> long extraSleepTime = sw.elapsed(TimeUnit.MILLISECONDS) - SLEEP_INTERVAL_MS;<a name="line.153"></a>
<span class="sourceLineNo">154</span> Map&lt;String, GcTimes&gt; gcTimesAfterSleep = getGcTimes();<a name="line.154"></a>
<span class="sourceLineNo">155</span><a name="line.155"></a>
<span class="sourceLineNo">156</span> if (extraSleepTime &gt; infoThresholdMs) {<a name="line.156"></a>
<span class="sourceLineNo">157</span> Set&lt;String&gt; gcBeanNames =<a name="line.157"></a>
<span class="sourceLineNo">158</span> Sets.intersection(gcTimesAfterSleep.keySet(), gcTimesBeforeSleep.keySet());<a name="line.158"></a>
<span class="sourceLineNo">159</span> List&lt;String&gt; gcDiffs = Lists.newArrayList();<a name="line.159"></a>
<span class="sourceLineNo">160</span> for (String name : gcBeanNames) {<a name="line.160"></a>
<span class="sourceLineNo">161</span> GcTimes diff = gcTimesAfterSleep.get(name).subtract(gcTimesBeforeSleep.get(name));<a name="line.161"></a>
<span class="sourceLineNo">162</span> if (diff.gcCount != 0) {<a name="line.162"></a>
<span class="sourceLineNo">163</span> gcDiffs.add("GC pool '" + name + "' had collection(s): " + diff.toString());<a name="line.163"></a>
<span class="sourceLineNo">164</span> }<a name="line.164"></a>
<span class="sourceLineNo">165</span> }<a name="line.165"></a>
<span class="sourceLineNo">166</span><a name="line.166"></a>
<span class="sourceLineNo">167</span> updateMetrics(extraSleepTime, !gcDiffs.isEmpty());<a name="line.167"></a>
<span class="sourceLineNo">168</span><a name="line.168"></a>
<span class="sourceLineNo">169</span> if (extraSleepTime &gt; warnThresholdMs) {<a name="line.169"></a>
<span class="sourceLineNo">170</span> LOG.warn(formatMessage(extraSleepTime, gcDiffs));<a name="line.170"></a>
<span class="sourceLineNo">171</span> } else {<a name="line.171"></a>
<span class="sourceLineNo">172</span> LOG.info(formatMessage(extraSleepTime, gcDiffs));<a name="line.172"></a>
<span class="sourceLineNo">173</span> }<a name="line.173"></a>
<span class="sourceLineNo">174</span> }<a name="line.174"></a>
<span class="sourceLineNo">175</span> gcTimesBeforeSleep = gcTimesAfterSleep;<a name="line.175"></a>
<span class="sourceLineNo">176</span> }<a name="line.176"></a>
<span class="sourceLineNo">177</span> }<a name="line.177"></a>
<span class="sourceLineNo">178</span> }<a name="line.178"></a>
<span class="sourceLineNo">179</span><a name="line.179"></a>
<span class="sourceLineNo">180</span> public void updateMetrics(long sleepTime, boolean gcDetected) {<a name="line.180"></a>
<span class="sourceLineNo">181</span> if (metricsSource != null) {<a name="line.181"></a>
<span class="sourceLineNo">182</span> if (sleepTime &gt; warnThresholdMs) {<a name="line.182"></a>
<span class="sourceLineNo">183</span> metricsSource.incWarnThresholdExceeded(1);<a name="line.183"></a>
<span class="sourceLineNo">184</span> } else {<a name="line.184"></a>
<span class="sourceLineNo">185</span> metricsSource.incInfoThresholdExceeded(1);<a name="line.185"></a>
<span class="sourceLineNo">186</span> }<a name="line.186"></a>
<span class="sourceLineNo">187</span> if (gcDetected) {<a name="line.187"></a>
<span class="sourceLineNo">188</span> metricsSource.updatePauseTimeWithGc(sleepTime);<a name="line.188"></a>
<span class="sourceLineNo">189</span> } else {<a name="line.189"></a>
<span class="sourceLineNo">190</span> metricsSource.updatePauseTimeWithoutGc(sleepTime);<a name="line.190"></a>
<span class="sourceLineNo">191</span> }<a name="line.191"></a>
<span class="sourceLineNo">192</span> }<a name="line.192"></a>
<span class="sourceLineNo">193</span> }<a name="line.193"></a>
<span class="sourceLineNo">194</span><a name="line.194"></a>
<span class="sourceLineNo">195</span> public JvmPauseMonitorSource getMetricsSource() {<a name="line.195"></a>
<span class="sourceLineNo">196</span> return metricsSource;<a name="line.196"></a>
<span class="sourceLineNo">197</span> }<a name="line.197"></a>
<span class="sourceLineNo">198</span><a name="line.198"></a>
<span class="sourceLineNo">199</span> public void setMetricsSource(JvmPauseMonitorSource metricsSource) {<a name="line.199"></a>
<span class="sourceLineNo">200</span> this.metricsSource = metricsSource;<a name="line.200"></a>
<span class="sourceLineNo">201</span> }<a name="line.201"></a>
<span class="sourceLineNo">202</span><a name="line.202"></a>
<span class="sourceLineNo">203</span> /**<a name="line.203"></a>
<span class="sourceLineNo">204</span> * Simple 'main' to facilitate manual testing of the pause monitor. This main function just leaks<a name="line.204"></a>
<span class="sourceLineNo">205</span> * memory into a list. Running this class with a 1GB heap will very quickly go into "GC hell" and<a name="line.205"></a>
<span class="sourceLineNo">206</span> * result in log messages about the GC pauses.<a name="line.206"></a>
<span class="sourceLineNo">207</span> */<a name="line.207"></a>
<span class="sourceLineNo">208</span> public static void main(String[] args) throws Exception {<a name="line.208"></a>
<span class="sourceLineNo">209</span> new JvmPauseMonitor(new Configuration()).start();<a name="line.209"></a>
<span class="sourceLineNo">210</span> List&lt;String&gt; list = Lists.newArrayList();<a name="line.210"></a>
<span class="sourceLineNo">211</span> int i = 0;<a name="line.211"></a>
<span class="sourceLineNo">212</span> while (true) {<a name="line.212"></a>
<span class="sourceLineNo">213</span> list.add(String.valueOf(i++));<a name="line.213"></a>
<span class="sourceLineNo">214</span> }<a name="line.214"></a>
<span class="sourceLineNo">215</span> }<a name="line.215"></a>
<span class="sourceLineNo">216</span>}<a name="line.216"></a>
</pre>
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