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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.io.hfile;<a name="line.18"></a>
<span class="sourceLineNo">019</span><a name="line.19"></a>
<span class="sourceLineNo">020</span>import java.io.File;<a name="line.20"></a>
<span class="sourceLineNo">021</span>import java.io.FileInputStream;<a name="line.21"></a>
<span class="sourceLineNo">022</span>import java.io.FileOutputStream;<a name="line.22"></a>
<span class="sourceLineNo">023</span>import java.io.IOException;<a name="line.23"></a>
<span class="sourceLineNo">024</span>import java.util.HashMap;<a name="line.24"></a>
<span class="sourceLineNo">025</span>import java.util.Map;<a name="line.25"></a>
<span class="sourceLineNo">026</span>import java.util.concurrent.ConcurrentSkipListMap;<a name="line.26"></a>
<span class="sourceLineNo">027</span>import java.util.concurrent.Future;<a name="line.27"></a>
<span class="sourceLineNo">028</span>import java.util.concurrent.RejectedExecutionException;<a name="line.28"></a>
<span class="sourceLineNo">029</span>import java.util.concurrent.ScheduledExecutorService;<a name="line.29"></a>
<span class="sourceLineNo">030</span>import java.util.concurrent.ScheduledThreadPoolExecutor;<a name="line.30"></a>
<span class="sourceLineNo">031</span>import java.util.concurrent.ThreadFactory;<a name="line.31"></a>
<span class="sourceLineNo">032</span>import java.util.concurrent.ThreadLocalRandom;<a name="line.32"></a>
<span class="sourceLineNo">033</span>import java.util.concurrent.TimeUnit;<a name="line.33"></a>
<span class="sourceLineNo">034</span>import java.util.regex.Pattern;<a name="line.34"></a>
<span class="sourceLineNo">035</span>import org.apache.hadoop.conf.Configuration;<a name="line.35"></a>
<span class="sourceLineNo">036</span>import org.apache.hadoop.fs.Path;<a name="line.36"></a>
<span class="sourceLineNo">037</span>import org.apache.hadoop.hbase.HBaseConfiguration;<a name="line.37"></a>
<span class="sourceLineNo">038</span>import org.apache.hadoop.hbase.HConstants;<a name="line.38"></a>
<span class="sourceLineNo">039</span>import org.apache.hadoop.hbase.trace.TraceUtil;<a name="line.39"></a>
<span class="sourceLineNo">040</span>import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;<a name="line.40"></a>
<span class="sourceLineNo">041</span>import org.apache.yetus.audience.InterfaceAudience;<a name="line.41"></a>
<span class="sourceLineNo">042</span>import org.slf4j.Logger;<a name="line.42"></a>
<span class="sourceLineNo">043</span>import org.slf4j.LoggerFactory;<a name="line.43"></a>
<span class="sourceLineNo">044</span><a name="line.44"></a>
<span class="sourceLineNo">045</span>import org.apache.hadoop.hbase.shaded.protobuf.generated.PersistentPrefetchProtos;<a name="line.45"></a>
<span class="sourceLineNo">046</span><a name="line.46"></a>
<span class="sourceLineNo">047</span>@InterfaceAudience.Private<a name="line.47"></a>
<span class="sourceLineNo">048</span>public final class PrefetchExecutor {<a name="line.48"></a>
<span class="sourceLineNo">049</span><a name="line.49"></a>
<span class="sourceLineNo">050</span> private static final Logger LOG = LoggerFactory.getLogger(PrefetchExecutor.class);<a name="line.50"></a>
<span class="sourceLineNo">051</span><a name="line.51"></a>
<span class="sourceLineNo">052</span> /** Futures for tracking block prefetch activity */<a name="line.52"></a>
<span class="sourceLineNo">053</span> private static final Map&lt;Path, Future&lt;?&gt;&gt; prefetchFutures = new ConcurrentSkipListMap&lt;&gt;();<a name="line.53"></a>
<span class="sourceLineNo">054</span> /** Set of files for which prefetch is completed */<a name="line.54"></a>
<span class="sourceLineNo">055</span> @edu.umd.cs.findbugs.annotations.SuppressWarnings(value = "MS_SHOULD_BE_FINAL")<a name="line.55"></a>
<span class="sourceLineNo">056</span> private static HashMap&lt;String, Boolean&gt; prefetchCompleted = new HashMap&lt;&gt;();<a name="line.56"></a>
<span class="sourceLineNo">057</span> /** Executor pool shared among all HFiles for block prefetch */<a name="line.57"></a>
<span class="sourceLineNo">058</span> private static final ScheduledExecutorService prefetchExecutorPool;<a name="line.58"></a>
<span class="sourceLineNo">059</span> /** Delay before beginning prefetch */<a name="line.59"></a>
<span class="sourceLineNo">060</span> private static final int prefetchDelayMillis;<a name="line.60"></a>
<span class="sourceLineNo">061</span> /** Variation in prefetch delay times, to mitigate stampedes */<a name="line.61"></a>
<span class="sourceLineNo">062</span> private static final float prefetchDelayVariation;<a name="line.62"></a>
<span class="sourceLineNo">063</span> static String prefetchedFileListPath;<a name="line.63"></a>
<span class="sourceLineNo">064</span> static {<a name="line.64"></a>
<span class="sourceLineNo">065</span> // Consider doing this on demand with a configuration passed in rather<a name="line.65"></a>
<span class="sourceLineNo">066</span> // than in a static initializer.<a name="line.66"></a>
<span class="sourceLineNo">067</span> Configuration conf = HBaseConfiguration.create();<a name="line.67"></a>
<span class="sourceLineNo">068</span> // 1s here for tests, consider 30s in hbase-default.xml<a name="line.68"></a>
<span class="sourceLineNo">069</span> // Set to 0 for no delay<a name="line.69"></a>
<span class="sourceLineNo">070</span> prefetchDelayMillis = conf.getInt("hbase.hfile.prefetch.delay", 1000);<a name="line.70"></a>
<span class="sourceLineNo">071</span> prefetchDelayVariation = conf.getFloat("hbase.hfile.prefetch.delay.variation", 0.2f);<a name="line.71"></a>
<span class="sourceLineNo">072</span> int prefetchThreads = conf.getInt("hbase.hfile.thread.prefetch", 4);<a name="line.72"></a>
<span class="sourceLineNo">073</span> prefetchExecutorPool = new ScheduledThreadPoolExecutor(prefetchThreads, new ThreadFactory() {<a name="line.73"></a>
<span class="sourceLineNo">074</span> @Override<a name="line.74"></a>
<span class="sourceLineNo">075</span> public Thread newThread(Runnable r) {<a name="line.75"></a>
<span class="sourceLineNo">076</span> String name = "hfile-prefetch-" + EnvironmentEdgeManager.currentTime();<a name="line.76"></a>
<span class="sourceLineNo">077</span> Thread t = new Thread(r, name);<a name="line.77"></a>
<span class="sourceLineNo">078</span> t.setDaemon(true);<a name="line.78"></a>
<span class="sourceLineNo">079</span> return t;<a name="line.79"></a>
<span class="sourceLineNo">080</span> }<a name="line.80"></a>
<span class="sourceLineNo">081</span> });<a name="line.81"></a>
<span class="sourceLineNo">082</span> }<a name="line.82"></a>
<span class="sourceLineNo">083</span><a name="line.83"></a>
<span class="sourceLineNo">084</span> // TODO: We want HFile, which is where the blockcache lives, to handle<a name="line.84"></a>
<span class="sourceLineNo">085</span> // prefetching of file blocks but the Store level is where path convention<a name="line.85"></a>
<span class="sourceLineNo">086</span> // knowledge should be contained<a name="line.86"></a>
<span class="sourceLineNo">087</span> private static final Pattern prefetchPathExclude =<a name="line.87"></a>
<span class="sourceLineNo">088</span> Pattern.compile("(" + Path.SEPARATOR_CHAR + HConstants.HBASE_TEMP_DIRECTORY.replace(".", "\\.")<a name="line.88"></a>
<span class="sourceLineNo">089</span> + Path.SEPARATOR_CHAR + ")|(" + Path.SEPARATOR_CHAR<a name="line.89"></a>
<span class="sourceLineNo">090</span> + HConstants.HREGION_COMPACTIONDIR_NAME.replace(".", "\\.") + Path.SEPARATOR_CHAR + ")");<a name="line.90"></a>
<span class="sourceLineNo">091</span><a name="line.91"></a>
<span class="sourceLineNo">092</span> public static void request(Path path, Runnable runnable) {<a name="line.92"></a>
<span class="sourceLineNo">093</span> if (prefetchCompleted != null) {<a name="line.93"></a>
<span class="sourceLineNo">094</span> if (isFilePrefetched(path.getName())) {<a name="line.94"></a>
<span class="sourceLineNo">095</span> LOG.info(<a name="line.95"></a>
<span class="sourceLineNo">096</span> "File has already been prefetched before the restart, so skipping prefetch : " + path);<a name="line.96"></a>
<span class="sourceLineNo">097</span> return;<a name="line.97"></a>
<span class="sourceLineNo">098</span> }<a name="line.98"></a>
<span class="sourceLineNo">099</span> }<a name="line.99"></a>
<span class="sourceLineNo">100</span> if (!prefetchPathExclude.matcher(path.toString()).find()) {<a name="line.100"></a>
<span class="sourceLineNo">101</span> long delay;<a name="line.101"></a>
<span class="sourceLineNo">102</span> if (prefetchDelayMillis &gt; 0) {<a name="line.102"></a>
<span class="sourceLineNo">103</span> delay = (long) ((prefetchDelayMillis * (1.0f - (prefetchDelayVariation / 2)))<a name="line.103"></a>
<span class="sourceLineNo">104</span> + (prefetchDelayMillis * (prefetchDelayVariation / 2)<a name="line.104"></a>
<span class="sourceLineNo">105</span> * ThreadLocalRandom.current().nextFloat()));<a name="line.105"></a>
<span class="sourceLineNo">106</span> } else {<a name="line.106"></a>
<span class="sourceLineNo">107</span> delay = 0;<a name="line.107"></a>
<span class="sourceLineNo">108</span> }<a name="line.108"></a>
<span class="sourceLineNo">109</span> try {<a name="line.109"></a>
<span class="sourceLineNo">110</span> LOG.debug("Prefetch requested for {}, delay={} ms", path, delay);<a name="line.110"></a>
<span class="sourceLineNo">111</span> final Runnable tracedRunnable =<a name="line.111"></a>
<span class="sourceLineNo">112</span> TraceUtil.tracedRunnable(runnable, "PrefetchExecutor.request");<a name="line.112"></a>
<span class="sourceLineNo">113</span> final Future&lt;?&gt; future =<a name="line.113"></a>
<span class="sourceLineNo">114</span> prefetchExecutorPool.schedule(tracedRunnable, delay, TimeUnit.MILLISECONDS);<a name="line.114"></a>
<span class="sourceLineNo">115</span> prefetchFutures.put(path, future);<a name="line.115"></a>
<span class="sourceLineNo">116</span> } catch (RejectedExecutionException e) {<a name="line.116"></a>
<span class="sourceLineNo">117</span> prefetchFutures.remove(path);<a name="line.117"></a>
<span class="sourceLineNo">118</span> LOG.warn("Prefetch request rejected for {}", path);<a name="line.118"></a>
<span class="sourceLineNo">119</span> }<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><a name="line.122"></a>
<span class="sourceLineNo">123</span> public static void complete(Path path) {<a name="line.123"></a>
<span class="sourceLineNo">124</span> prefetchFutures.remove(path);<a name="line.124"></a>
<span class="sourceLineNo">125</span> prefetchCompleted.put(path.getName(), true);<a name="line.125"></a>
<span class="sourceLineNo">126</span> LOG.debug("Prefetch completed for {}", path.getName());<a name="line.126"></a>
<span class="sourceLineNo">127</span> }<a name="line.127"></a>
<span class="sourceLineNo">128</span><a name="line.128"></a>
<span class="sourceLineNo">129</span> public static void cancel(Path path) {<a name="line.129"></a>
<span class="sourceLineNo">130</span> Future&lt;?&gt; future = prefetchFutures.get(path);<a name="line.130"></a>
<span class="sourceLineNo">131</span> if (future != null) {<a name="line.131"></a>
<span class="sourceLineNo">132</span> // ok to race with other cancellation attempts<a name="line.132"></a>
<span class="sourceLineNo">133</span> future.cancel(true);<a name="line.133"></a>
<span class="sourceLineNo">134</span> prefetchFutures.remove(path);<a name="line.134"></a>
<span class="sourceLineNo">135</span> LOG.debug("Prefetch cancelled for {}", path);<a name="line.135"></a>
<span class="sourceLineNo">136</span> }<a name="line.136"></a>
<span class="sourceLineNo">137</span> LOG.debug("Removing filename from the prefetched persistence list: {}", path.getName());<a name="line.137"></a>
<span class="sourceLineNo">138</span> removePrefetchedFileWhileEvict(path.getName());<a name="line.138"></a>
<span class="sourceLineNo">139</span> }<a name="line.139"></a>
<span class="sourceLineNo">140</span><a name="line.140"></a>
<span class="sourceLineNo">141</span> public static boolean isCompleted(Path path) {<a name="line.141"></a>
<span class="sourceLineNo">142</span> Future&lt;?&gt; future = prefetchFutures.get(path);<a name="line.142"></a>
<span class="sourceLineNo">143</span> if (future != null) {<a name="line.143"></a>
<span class="sourceLineNo">144</span> return future.isDone();<a name="line.144"></a>
<span class="sourceLineNo">145</span> }<a name="line.145"></a>
<span class="sourceLineNo">146</span> return true;<a name="line.146"></a>
<span class="sourceLineNo">147</span> }<a name="line.147"></a>
<span class="sourceLineNo">148</span><a name="line.148"></a>
<span class="sourceLineNo">149</span> @edu.umd.cs.findbugs.annotations.SuppressWarnings(value = "OBL_UNSATISFIED_OBLIGATION",<a name="line.149"></a>
<span class="sourceLineNo">150</span> justification = "false positive, try-with-resources ensures close is called.")<a name="line.150"></a>
<span class="sourceLineNo">151</span> public static void persistToFile(String path) throws IOException {<a name="line.151"></a>
<span class="sourceLineNo">152</span> prefetchedFileListPath = path;<a name="line.152"></a>
<span class="sourceLineNo">153</span> if (prefetchedFileListPath == null) {<a name="line.153"></a>
<span class="sourceLineNo">154</span> LOG.info("Exception while persisting prefetch!");<a name="line.154"></a>
<span class="sourceLineNo">155</span> throw new IOException("Error persisting prefetched HFiles set!");<a name="line.155"></a>
<span class="sourceLineNo">156</span> }<a name="line.156"></a>
<span class="sourceLineNo">157</span> if (!prefetchCompleted.isEmpty()) {<a name="line.157"></a>
<span class="sourceLineNo">158</span> try (FileOutputStream fos = new FileOutputStream(prefetchedFileListPath, false)) {<a name="line.158"></a>
<span class="sourceLineNo">159</span> PrefetchProtoUtils.toPB(prefetchCompleted).writeDelimitedTo(fos);<a name="line.159"></a>
<span class="sourceLineNo">160</span> }<a name="line.160"></a>
<span class="sourceLineNo">161</span> }<a name="line.161"></a>
<span class="sourceLineNo">162</span> }<a name="line.162"></a>
<span class="sourceLineNo">163</span><a name="line.163"></a>
<span class="sourceLineNo">164</span> public static void retrieveFromFile(String path) throws IOException {<a name="line.164"></a>
<span class="sourceLineNo">165</span> prefetchedFileListPath = path;<a name="line.165"></a>
<span class="sourceLineNo">166</span> File prefetchPersistenceFile = new File(prefetchedFileListPath);<a name="line.166"></a>
<span class="sourceLineNo">167</span> if (!prefetchPersistenceFile.exists()) {<a name="line.167"></a>
<span class="sourceLineNo">168</span> LOG.warn("Prefetch persistence file does not exist!");<a name="line.168"></a>
<span class="sourceLineNo">169</span> return;<a name="line.169"></a>
<span class="sourceLineNo">170</span> }<a name="line.170"></a>
<span class="sourceLineNo">171</span> LOG.info("Retrieving from prefetch persistence file " + path);<a name="line.171"></a>
<span class="sourceLineNo">172</span> assert (prefetchedFileListPath != null);<a name="line.172"></a>
<span class="sourceLineNo">173</span> try (FileInputStream fis = deleteFileOnClose(prefetchPersistenceFile)) {<a name="line.173"></a>
<span class="sourceLineNo">174</span> PersistentPrefetchProtos.PrefetchedHfileName proto =<a name="line.174"></a>
<span class="sourceLineNo">175</span> PersistentPrefetchProtos.PrefetchedHfileName.parseDelimitedFrom(fis);<a name="line.175"></a>
<span class="sourceLineNo">176</span> Map&lt;String, Boolean&gt; protoPrefetchedFilesMap = proto.getPrefetchedFilesMap();<a name="line.176"></a>
<span class="sourceLineNo">177</span> prefetchCompleted.putAll(protoPrefetchedFilesMap);<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><a name="line.180"></a>
<span class="sourceLineNo">181</span> private static FileInputStream deleteFileOnClose(final File file) throws IOException {<a name="line.181"></a>
<span class="sourceLineNo">182</span> return new FileInputStream(file) {<a name="line.182"></a>
<span class="sourceLineNo">183</span> private File myFile;<a name="line.183"></a>
<span class="sourceLineNo">184</span><a name="line.184"></a>
<span class="sourceLineNo">185</span> private FileInputStream init(File file) {<a name="line.185"></a>
<span class="sourceLineNo">186</span> myFile = file;<a name="line.186"></a>
<span class="sourceLineNo">187</span> return this;<a name="line.187"></a>
<span class="sourceLineNo">188</span> }<a name="line.188"></a>
<span class="sourceLineNo">189</span><a name="line.189"></a>
<span class="sourceLineNo">190</span> @Override<a name="line.190"></a>
<span class="sourceLineNo">191</span> public void close() throws IOException {<a name="line.191"></a>
<span class="sourceLineNo">192</span> if (myFile == null) {<a name="line.192"></a>
<span class="sourceLineNo">193</span> return;<a name="line.193"></a>
<span class="sourceLineNo">194</span> }<a name="line.194"></a>
<span class="sourceLineNo">195</span><a name="line.195"></a>
<span class="sourceLineNo">196</span> super.close();<a name="line.196"></a>
<span class="sourceLineNo">197</span> if (!myFile.delete()) {<a name="line.197"></a>
<span class="sourceLineNo">198</span> throw new IOException("Failed deleting persistence file " + myFile.getAbsolutePath());<a name="line.198"></a>
<span class="sourceLineNo">199</span> }<a name="line.199"></a>
<span class="sourceLineNo">200</span> myFile = null;<a name="line.200"></a>
<span class="sourceLineNo">201</span> }<a name="line.201"></a>
<span class="sourceLineNo">202</span> }.init(file);<a name="line.202"></a>
<span class="sourceLineNo">203</span> }<a name="line.203"></a>
<span class="sourceLineNo">204</span><a name="line.204"></a>
<span class="sourceLineNo">205</span> public static void removePrefetchedFileWhileEvict(String hfileName) {<a name="line.205"></a>
<span class="sourceLineNo">206</span> prefetchCompleted.remove(hfileName);<a name="line.206"></a>
<span class="sourceLineNo">207</span> }<a name="line.207"></a>
<span class="sourceLineNo">208</span><a name="line.208"></a>
<span class="sourceLineNo">209</span> public static boolean isFilePrefetched(String hfileName) {<a name="line.209"></a>
<span class="sourceLineNo">210</span> return prefetchCompleted.containsKey(hfileName);<a name="line.210"></a>
<span class="sourceLineNo">211</span> }<a name="line.211"></a>
<span class="sourceLineNo">212</span><a name="line.212"></a>
<span class="sourceLineNo">213</span> private PrefetchExecutor() {<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>
</pre>
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