[30/51] [partial] hbase-site git commit: Published site at .

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http://git-wip-us.apache.org/repos/asf/hbase-site/blob/7816cbde/devapidocs/src-html/org/apache/hadoop/hbase/coprocessor/example/ZooKeeperScanPolicyObserver.ZKDataHolder.html
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+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 
"http://www.w3.org/TR/html4/loose.dtd";>
+<html lang="en">
+<head>
+<title>Source code</title>
+<link rel="stylesheet" type="text/css" 
href="../../../../../../../stylesheet.css" title="Style">
+</head>
+<body>
+<div class="sourceContainer">
+<pre><span class="sourceLineNo">001</span>/**<a name="line.1"></a>
+<span class="sourceLineNo">002</span> * Copyright The Apache Software 
Foundation<a name="line.2"></a>
+<span class="sourceLineNo">003</span> *<a name="line.3"></a>
+<span class="sourceLineNo">004</span> * Licensed to the Apache Software 
Foundation (ASF) under one or more<a name="line.4"></a>
+<span class="sourceLineNo">005</span> * contributor license agreements. See 
the NOTICE file distributed with this<a name="line.5"></a>
+<span class="sourceLineNo">006</span> * work for additional information 
regarding copyright ownership. The ASF<a name="line.6"></a>
+<span class="sourceLineNo">007</span> * licenses this file to you under the 
Apache License, Version 2.0 (the<a name="line.7"></a>
+<span class="sourceLineNo">008</span> * "License"); you may not use this file 
except in compliance with the License.<a name="line.8"></a>
+<span class="sourceLineNo">009</span> * You may obtain a copy of the License 
at<a name="line.9"></a>
+<span class="sourceLineNo">010</span> *<a name="line.10"></a>
+<span class="sourceLineNo">011</span> *     
http://www.apache.org/licenses/LICENSE-2.0<a name="line.11"></a>
+<span class="sourceLineNo">012</span> *<a name="line.12"></a>
+<span class="sourceLineNo">013</span> * Unless required by applicable law or 
agreed to in writing, software<a name="line.13"></a>
+<span class="sourceLineNo">014</span> * distributed under the License is 
distributed on an "AS IS" BASIS, WITHOUT<a name="line.14"></a>
+<span class="sourceLineNo">015</span> * WARRANTIES OR CONDITIONS OF ANY KIND, 
either express or implied. See the<a name="line.15"></a>
+<span class="sourceLineNo">016</span> * License for the specific language 
governing permissions and limitations<a name="line.16"></a>
+<span class="sourceLineNo">017</span> * under the License.<a 
name="line.17"></a>
+<span class="sourceLineNo">018</span> */<a name="line.18"></a>
+<span class="sourceLineNo">019</span>package 
org.apache.hadoop.hbase.coprocessor.example;<a name="line.19"></a>
+<span class="sourceLineNo">020</span><a name="line.20"></a>
+<span class="sourceLineNo">021</span>import java.io.IOException;<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.Optional;<a 
name="line.23"></a>
+<span class="sourceLineNo">024</span>import java.util.OptionalLong;<a 
name="line.24"></a>
+<span class="sourceLineNo">025</span><a name="line.25"></a>
+<span class="sourceLineNo">026</span>import 
org.apache.curator.framework.CuratorFramework;<a name="line.26"></a>
+<span class="sourceLineNo">027</span>import 
org.apache.curator.framework.CuratorFrameworkFactory;<a name="line.27"></a>
+<span class="sourceLineNo">028</span>import 
org.apache.curator.framework.recipes.cache.ChildData;<a name="line.28"></a>
+<span class="sourceLineNo">029</span>import 
org.apache.curator.framework.recipes.cache.NodeCache;<a name="line.29"></a>
+<span class="sourceLineNo">030</span>import 
org.apache.curator.retry.RetryForever;<a name="line.30"></a>
+<span class="sourceLineNo">031</span>import org.apache.hadoop.hbase.Cell;<a 
name="line.31"></a>
+<span class="sourceLineNo">032</span>import 
org.apache.hadoop.hbase.CoprocessorEnvironment;<a name="line.32"></a>
+<span class="sourceLineNo">033</span>import 
org.apache.hadoop.hbase.coprocessor.ObserverContext;<a name="line.33"></a>
+<span class="sourceLineNo">034</span>import 
org.apache.hadoop.hbase.coprocessor.RegionCoprocessor;<a name="line.34"></a>
+<span class="sourceLineNo">035</span>import 
org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;<a 
name="line.35"></a>
+<span class="sourceLineNo">036</span>import 
org.apache.hadoop.hbase.coprocessor.RegionObserver;<a name="line.36"></a>
+<span class="sourceLineNo">037</span>import 
org.apache.hadoop.hbase.regionserver.InternalScanner;<a name="line.37"></a>
+<span class="sourceLineNo">038</span>import 
org.apache.hadoop.hbase.regionserver.ScanType;<a name="line.38"></a>
+<span class="sourceLineNo">039</span>import 
org.apache.hadoop.hbase.regionserver.ScannerContext;<a name="line.39"></a>
+<span class="sourceLineNo">040</span>import 
org.apache.hadoop.hbase.regionserver.Store;<a name="line.40"></a>
+<span class="sourceLineNo">041</span>import 
org.apache.hadoop.hbase.regionserver.compactions.CompactionLifeCycleTracker;<a 
name="line.41"></a>
+<span class="sourceLineNo">042</span>import 
org.apache.hadoop.hbase.regionserver.compactions.CompactionRequest;<a 
name="line.42"></a>
+<span class="sourceLineNo">043</span>import 
org.apache.hadoop.hbase.util.Bytes;<a name="line.43"></a>
+<span class="sourceLineNo">044</span><a name="line.44"></a>
+<span class="sourceLineNo">045</span>/**<a name="line.45"></a>
+<span class="sourceLineNo">046</span> * This is an example showing how a 
RegionObserver could configured via ZooKeeper in order to<a name="line.46"></a>
+<span class="sourceLineNo">047</span> * control a Region compaction, flush, 
and scan policy. This also demonstrated the use of shared<a name="line.47"></a>
+<span class="sourceLineNo">048</span> * {@link 
org.apache.hadoop.hbase.coprocessor.RegionObserver} state. See<a 
name="line.48"></a>
+<span class="sourceLineNo">049</span> * {@link 
RegionCoprocessorEnvironment#getSharedData()}.<a name="line.49"></a>
+<span class="sourceLineNo">050</span> * &lt;p&gt;<a name="line.50"></a>
+<span class="sourceLineNo">051</span> * This would be useful for an 
incremental backup tool, which would indicate the last time of a<a 
name="line.51"></a>
+<span class="sourceLineNo">052</span> * successful backup via ZK and instruct 
HBase that to safely delete the data which has already been<a 
name="line.52"></a>
+<span class="sourceLineNo">053</span> * backup.<a name="line.53"></a>
+<span class="sourceLineNo">054</span> */<a name="line.54"></a>
+<span class="sourceLineNo">055</span>public class ZooKeeperScanPolicyObserver 
implements RegionCoprocessor, RegionObserver {<a name="line.55"></a>
+<span class="sourceLineNo">056</span><a name="line.56"></a>
+<span class="sourceLineNo">057</span>  @Override<a name="line.57"></a>
+<span class="sourceLineNo">058</span>  public Optional&lt;RegionObserver&gt; 
getRegionObserver() {<a name="line.58"></a>
+<span class="sourceLineNo">059</span>    return Optional.of(this);<a 
name="line.59"></a>
+<span class="sourceLineNo">060</span>  }<a name="line.60"></a>
+<span class="sourceLineNo">061</span><a name="line.61"></a>
+<span class="sourceLineNo">062</span>  // The zk ensemble info is put in hbase 
config xml with given custom key.<a name="line.62"></a>
+<span class="sourceLineNo">063</span>  public static final String 
ZK_ENSEMBLE_KEY = "ZooKeeperScanPolicyObserver.zookeeper.ensemble";<a 
name="line.63"></a>
+<span class="sourceLineNo">064</span>  public static final String 
ZK_SESSION_TIMEOUT_KEY =<a name="line.64"></a>
+<span class="sourceLineNo">065</span>      
"ZooKeeperScanPolicyObserver.zookeeper.session.timeout";<a name="line.65"></a>
+<span class="sourceLineNo">066</span>  public static final int 
ZK_SESSION_TIMEOUT_DEFAULT = 30 * 1000; // 30 secs<a name="line.66"></a>
+<span class="sourceLineNo">067</span>  public static final String NODE = 
"/backup/example/lastbackup";<a name="line.67"></a>
+<span class="sourceLineNo">068</span>  private static final String ZKKEY = 
"ZK";<a name="line.68"></a>
+<span class="sourceLineNo">069</span><a name="line.69"></a>
+<span class="sourceLineNo">070</span>  private NodeCache cache;<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>   * Internal watcher that keep "data" up 
to date asynchronously.<a name="line.73"></a>
+<span class="sourceLineNo">074</span>   */<a name="line.74"></a>
+<span class="sourceLineNo">075</span>  private static final class ZKDataHolder 
{<a name="line.75"></a>
+<span class="sourceLineNo">076</span><a name="line.76"></a>
+<span class="sourceLineNo">077</span>    private final String ensemble;<a 
name="line.77"></a>
+<span class="sourceLineNo">078</span><a name="line.78"></a>
+<span class="sourceLineNo">079</span>    private final int sessionTimeout;<a 
name="line.79"></a>
+<span class="sourceLineNo">080</span><a name="line.80"></a>
+<span class="sourceLineNo">081</span>    private CuratorFramework client;<a 
name="line.81"></a>
+<span class="sourceLineNo">082</span><a name="line.82"></a>
+<span class="sourceLineNo">083</span>    private NodeCache cache;<a 
name="line.83"></a>
+<span class="sourceLineNo">084</span><a name="line.84"></a>
+<span class="sourceLineNo">085</span>    private int ref;<a name="line.85"></a>
+<span class="sourceLineNo">086</span><a name="line.86"></a>
+<span class="sourceLineNo">087</span>    public ZKDataHolder(String ensemble, 
int sessionTimeout) {<a name="line.87"></a>
+<span class="sourceLineNo">088</span>      this.ensemble = ensemble;<a 
name="line.88"></a>
+<span class="sourceLineNo">089</span>      this.sessionTimeout = 
sessionTimeout;<a name="line.89"></a>
+<span class="sourceLineNo">090</span>    }<a name="line.90"></a>
+<span class="sourceLineNo">091</span><a name="line.91"></a>
+<span class="sourceLineNo">092</span>    private void create() throws 
Exception {<a name="line.92"></a>
+<span class="sourceLineNo">093</span>      client =<a name="line.93"></a>
+<span class="sourceLineNo">094</span>          
CuratorFrameworkFactory.builder().connectString(ensemble).sessionTimeoutMs(sessionTimeout)<a
 name="line.94"></a>
+<span class="sourceLineNo">095</span>              .retryPolicy(new 
RetryForever(1000)).canBeReadOnly(true).build();<a name="line.95"></a>
+<span class="sourceLineNo">096</span>      client.start();<a 
name="line.96"></a>
+<span class="sourceLineNo">097</span>      cache = new NodeCache(client, 
NODE);<a name="line.97"></a>
+<span class="sourceLineNo">098</span>      cache.start(true);<a 
name="line.98"></a>
+<span class="sourceLineNo">099</span>    }<a name="line.99"></a>
+<span class="sourceLineNo">100</span><a name="line.100"></a>
+<span class="sourceLineNo">101</span>    private void close() {<a 
name="line.101"></a>
+<span class="sourceLineNo">102</span>      if (cache != null) {<a 
name="line.102"></a>
+<span class="sourceLineNo">103</span>        try {<a name="line.103"></a>
+<span class="sourceLineNo">104</span>          cache.close();<a 
name="line.104"></a>
+<span class="sourceLineNo">105</span>        } catch (IOException e) {<a 
name="line.105"></a>
+<span class="sourceLineNo">106</span>          // should not happen<a 
name="line.106"></a>
+<span class="sourceLineNo">107</span>          throw new AssertionError(e);<a 
name="line.107"></a>
+<span class="sourceLineNo">108</span>        }<a name="line.108"></a>
+<span class="sourceLineNo">109</span>        cache = null;<a 
name="line.109"></a>
+<span class="sourceLineNo">110</span>      }<a name="line.110"></a>
+<span class="sourceLineNo">111</span>      if (client != null) {<a 
name="line.111"></a>
+<span class="sourceLineNo">112</span>        client.close();<a 
name="line.112"></a>
+<span class="sourceLineNo">113</span>        client = null;<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><a name="line.116"></a>
+<span class="sourceLineNo">117</span>    public synchronized NodeCache 
acquire() throws Exception {<a name="line.117"></a>
+<span class="sourceLineNo">118</span>      if (ref == 0) {<a 
name="line.118"></a>
+<span class="sourceLineNo">119</span>        try {<a name="line.119"></a>
+<span class="sourceLineNo">120</span>          create();<a name="line.120"></a>
+<span class="sourceLineNo">121</span>        } catch (Exception e) {<a 
name="line.121"></a>
+<span class="sourceLineNo">122</span>          close();<a name="line.122"></a>
+<span class="sourceLineNo">123</span>          throw e;<a name="line.123"></a>
+<span class="sourceLineNo">124</span>        }<a name="line.124"></a>
+<span class="sourceLineNo">125</span>      }<a name="line.125"></a>
+<span class="sourceLineNo">126</span>      ref++;<a name="line.126"></a>
+<span class="sourceLineNo">127</span>      return cache;<a name="line.127"></a>
+<span class="sourceLineNo">128</span>    }<a name="line.128"></a>
+<span class="sourceLineNo">129</span><a name="line.129"></a>
+<span class="sourceLineNo">130</span>    public synchronized void release() 
{<a name="line.130"></a>
+<span class="sourceLineNo">131</span>      ref--;<a name="line.131"></a>
+<span class="sourceLineNo">132</span>      if (ref == 0) {<a 
name="line.132"></a>
+<span class="sourceLineNo">133</span>        close();<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>  }<a name="line.136"></a>
+<span class="sourceLineNo">137</span><a name="line.137"></a>
+<span class="sourceLineNo">138</span>  @Override<a name="line.138"></a>
+<span class="sourceLineNo">139</span>  public void 
start(CoprocessorEnvironment env) throws IOException {<a name="line.139"></a>
+<span class="sourceLineNo">140</span>    RegionCoprocessorEnvironment renv = 
(RegionCoprocessorEnvironment) env;<a name="line.140"></a>
+<span class="sourceLineNo">141</span>    try {<a name="line.141"></a>
+<span class="sourceLineNo">142</span>      this.cache = ((ZKDataHolder) 
renv.getSharedData().computeIfAbsent(ZKKEY, k -&gt; {<a name="line.142"></a>
+<span class="sourceLineNo">143</span>        String ensemble = 
renv.getConfiguration().get(ZK_ENSEMBLE_KEY);<a name="line.143"></a>
+<span class="sourceLineNo">144</span>        int sessionTimeout =<a 
name="line.144"></a>
+<span class="sourceLineNo">145</span>            
renv.getConfiguration().getInt(ZK_SESSION_TIMEOUT_KEY, 
ZK_SESSION_TIMEOUT_DEFAULT);<a name="line.145"></a>
+<span class="sourceLineNo">146</span>        return new ZKDataHolder(ensemble, 
sessionTimeout);<a name="line.146"></a>
+<span class="sourceLineNo">147</span>      })).acquire();<a 
name="line.147"></a>
+<span class="sourceLineNo">148</span>    } catch (Exception e) {<a 
name="line.148"></a>
+<span class="sourceLineNo">149</span>      throw new IOException(e);<a 
name="line.149"></a>
+<span class="sourceLineNo">150</span>    }<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>  @Override<a name="line.153"></a>
+<span class="sourceLineNo">154</span>  public void stop(CoprocessorEnvironment 
env) throws IOException {<a name="line.154"></a>
+<span class="sourceLineNo">155</span>    RegionCoprocessorEnvironment renv = 
(RegionCoprocessorEnvironment) env;<a name="line.155"></a>
+<span class="sourceLineNo">156</span>    this.cache = null;<a 
name="line.156"></a>
+<span class="sourceLineNo">157</span>    ((ZKDataHolder) 
renv.getSharedData().get(ZKKEY)).release();<a name="line.157"></a>
+<span class="sourceLineNo">158</span>  }<a name="line.158"></a>
+<span class="sourceLineNo">159</span><a name="line.159"></a>
+<span class="sourceLineNo">160</span>  private OptionalLong getExpireBefore() 
{<a name="line.160"></a>
+<span class="sourceLineNo">161</span>    ChildData data = 
cache.getCurrentData();<a name="line.161"></a>
+<span class="sourceLineNo">162</span>    if (data == null) {<a 
name="line.162"></a>
+<span class="sourceLineNo">163</span>      return OptionalLong.empty();<a 
name="line.163"></a>
+<span class="sourceLineNo">164</span>    }<a name="line.164"></a>
+<span class="sourceLineNo">165</span>    byte[] bytes = data.getData();<a 
name="line.165"></a>
+<span class="sourceLineNo">166</span>    if (bytes == null || bytes.length != 
Long.BYTES) {<a name="line.166"></a>
+<span class="sourceLineNo">167</span>      return OptionalLong.empty();<a 
name="line.167"></a>
+<span class="sourceLineNo">168</span>    }<a name="line.168"></a>
+<span class="sourceLineNo">169</span>    return 
OptionalLong.of(Bytes.toLong(bytes));<a name="line.169"></a>
+<span class="sourceLineNo">170</span>  }<a name="line.170"></a>
+<span class="sourceLineNo">171</span><a name="line.171"></a>
+<span class="sourceLineNo">172</span>  private InternalScanner 
wrap(InternalScanner scanner) {<a name="line.172"></a>
+<span class="sourceLineNo">173</span>    OptionalLong optExpireBefore = 
getExpireBefore();<a name="line.173"></a>
+<span class="sourceLineNo">174</span>    if (!optExpireBefore.isPresent()) {<a 
name="line.174"></a>
+<span class="sourceLineNo">175</span>      return scanner;<a 
name="line.175"></a>
+<span class="sourceLineNo">176</span>    }<a name="line.176"></a>
+<span class="sourceLineNo">177</span>    long expireBefore = 
optExpireBefore.getAsLong();<a name="line.177"></a>
+<span class="sourceLineNo">178</span>    return new 
DelegatingInternalScanner(scanner) {<a name="line.178"></a>
+<span class="sourceLineNo">179</span><a name="line.179"></a>
+<span class="sourceLineNo">180</span>      @Override<a name="line.180"></a>
+<span class="sourceLineNo">181</span>      public boolean 
next(List&lt;Cell&gt; result, ScannerContext scannerContext) throws IOException 
{<a name="line.181"></a>
+<span class="sourceLineNo">182</span>        boolean moreRows = 
scanner.next(result, scannerContext);<a name="line.182"></a>
+<span class="sourceLineNo">183</span>        result.removeIf(c -&gt; 
c.getTimestamp() &lt; expireBefore);<a name="line.183"></a>
+<span class="sourceLineNo">184</span>        return moreRows;<a 
name="line.184"></a>
+<span class="sourceLineNo">185</span>      }<a name="line.185"></a>
+<span class="sourceLineNo">186</span>    };<a name="line.186"></a>
+<span class="sourceLineNo">187</span>  }<a name="line.187"></a>
+<span class="sourceLineNo">188</span><a name="line.188"></a>
+<span class="sourceLineNo">189</span>  @Override<a name="line.189"></a>
+<span class="sourceLineNo">190</span>  public InternalScanner 
preFlush(ObserverContext&lt;RegionCoprocessorEnvironment&gt; c, Store store,<a 
name="line.190"></a>
+<span class="sourceLineNo">191</span>      InternalScanner scanner) throws 
IOException {<a name="line.191"></a>
+<span class="sourceLineNo">192</span>    return wrap(scanner);<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>  @Override<a name="line.195"></a>
+<span class="sourceLineNo">196</span>  public InternalScanner 
preCompact(ObserverContext&lt;RegionCoprocessorEnvironment&gt; c, Store 
store,<a name="line.196"></a>
+<span class="sourceLineNo">197</span>      InternalScanner scanner, ScanType 
scanType, CompactionLifeCycleTracker tracker,<a name="line.197"></a>
+<span class="sourceLineNo">198</span>      CompactionRequest request) throws 
IOException {<a name="line.198"></a>
+<span class="sourceLineNo">199</span>    return wrap(scanner);<a 
name="line.199"></a>
+<span class="sourceLineNo">200</span>  }<a name="line.200"></a>
+<span class="sourceLineNo">201</span>}<a name="line.201"></a>
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+</pre>
+</div>
+</body>
+</html>


http://git-wip-us.apache.org/repos/asf/hbase-site/blob/7816cbde/devapidocs/src-html/org/apache/hadoop/hbase/coprocessor/example/ZooKeeperScanPolicyObserver.ZKWatcher.html
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diff --git 
a/devapidocs/src-html/org/apache/hadoop/hbase/coprocessor/example/ZooKeeperScanPolicyObserver.ZKWatcher.html
 
b/devapidocs/src-html/org/apache/hadoop/hbase/coprocessor/example/ZooKeeperScanPolicyObserver.ZKWatcher.html
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@@ -1,327 +0,0 @@
-<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 
"http://www.w3.org/TR/html4/loose.dtd";>
-<html lang="en">
-<head>
-<title>Source code</title>
-<link rel="stylesheet" type="text/css" 
href="../../../../../../../stylesheet.css" title="Style">
-</head>
-<body>
-<div class="sourceContainer">
-<pre><span class="sourceLineNo">001</span>/*<a name="line.1"></a>
-<span class="sourceLineNo">002</span> * Copyright The Apache Software 
Foundation<a name="line.2"></a>
-<span class="sourceLineNo">003</span> *<a name="line.3"></a>
-<span class="sourceLineNo">004</span> * Licensed to the Apache Software 
Foundation (ASF) under one or more<a name="line.4"></a>
-<span class="sourceLineNo">005</span> * contributor license agreements. See 
the NOTICE file distributed with this<a name="line.5"></a>
-<span class="sourceLineNo">006</span> * work for additional information 
regarding copyright ownership. The ASF<a name="line.6"></a>
-<span class="sourceLineNo">007</span> * licenses this file to you under the 
Apache License, Version 2.0 (the<a name="line.7"></a>
-<span class="sourceLineNo">008</span> * "License"); you may not use this file 
except in compliance with the License.<a name="line.8"></a>
-<span class="sourceLineNo">009</span> * You may obtain a copy of the License 
at<a name="line.9"></a>
-<span class="sourceLineNo">010</span> *<a name="line.10"></a>
-<span class="sourceLineNo">011</span> *     
http://www.apache.org/licenses/LICENSE-2.0<a name="line.11"></a>
-<span class="sourceLineNo">012</span> *<a name="line.12"></a>
-<span class="sourceLineNo">013</span> * Unless required by applicable law or 
agreed to in writing, software<a name="line.13"></a>
-<span class="sourceLineNo">014</span> * distributed under the License is 
distributed on an "AS IS" BASIS, WITHOUT<a name="line.14"></a>
-<span class="sourceLineNo">015</span> * WARRANTIES OR CONDITIONS OF ANY KIND, 
either express or implied. See the<a name="line.15"></a>
-<span class="sourceLineNo">016</span> * License for the specific language 
governing permissions and limitations<a name="line.16"></a>
-<span class="sourceLineNo">017</span> * under the License.<a 
name="line.17"></a>
-<span class="sourceLineNo">018</span> */<a name="line.18"></a>
-<span class="sourceLineNo">019</span>package 
org.apache.hadoop.hbase.coprocessor.example;<a name="line.19"></a>
-<span class="sourceLineNo">020</span><a name="line.20"></a>
-<span class="sourceLineNo">021</span>import java.io.IOException;<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.NavigableSet;<a 
name="line.23"></a>
-<span class="sourceLineNo">024</span>import java.util.Optional;<a 
name="line.24"></a>
-<span class="sourceLineNo">025</span>import java.util.OptionalInt;<a 
name="line.25"></a>
-<span class="sourceLineNo">026</span><a name="line.26"></a>
-<span class="sourceLineNo">027</span>import org.apache.commons.logging.Log;<a 
name="line.27"></a>
-<span class="sourceLineNo">028</span>import 
org.apache.commons.logging.LogFactory;<a name="line.28"></a>
-<span class="sourceLineNo">029</span>import 
org.apache.hadoop.hbase.CoprocessorEnvironment;<a name="line.29"></a>
-<span class="sourceLineNo">030</span>import 
org.apache.hadoop.hbase.HConstants;<a name="line.30"></a>
-<span class="sourceLineNo">031</span>import 
org.apache.hadoop.hbase.client.IsolationLevel;<a name="line.31"></a>
-<span class="sourceLineNo">032</span>import 
org.apache.hadoop.hbase.client.Scan;<a name="line.32"></a>
-<span class="sourceLineNo">033</span>import 
org.apache.hadoop.hbase.coprocessor.ObserverContext;<a name="line.33"></a>
-<span class="sourceLineNo">034</span>import 
org.apache.hadoop.hbase.coprocessor.RegionCoprocessor;<a name="line.34"></a>
-<span class="sourceLineNo">035</span>import 
org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;<a 
name="line.35"></a>
-<span class="sourceLineNo">036</span>import 
org.apache.hadoop.hbase.coprocessor.RegionObserver;<a name="line.36"></a>
-<span class="sourceLineNo">037</span>import 
org.apache.hadoop.hbase.regionserver.HStore;<a name="line.37"></a>
-<span class="sourceLineNo">038</span>import 
org.apache.hadoop.hbase.regionserver.InternalScanner;<a name="line.38"></a>
-<span class="sourceLineNo">039</span>import 
org.apache.hadoop.hbase.regionserver.KeyValueScanner;<a name="line.39"></a>
-<span class="sourceLineNo">040</span>import 
org.apache.hadoop.hbase.regionserver.ScanInfo;<a name="line.40"></a>
-<span class="sourceLineNo">041</span>import 
org.apache.hadoop.hbase.regionserver.ScanType;<a name="line.41"></a>
-<span class="sourceLineNo">042</span>import 
org.apache.hadoop.hbase.regionserver.Store;<a name="line.42"></a>
-<span class="sourceLineNo">043</span>import 
org.apache.hadoop.hbase.regionserver.StoreScanner;<a name="line.43"></a>
-<span class="sourceLineNo">044</span>import 
org.apache.hadoop.hbase.regionserver.compactions.CompactionLifeCycleTracker;<a 
name="line.44"></a>
-<span class="sourceLineNo">045</span>import 
org.apache.hadoop.hbase.regionserver.compactions.CompactionRequest;<a 
name="line.45"></a>
-<span class="sourceLineNo">046</span>import 
org.apache.hadoop.hbase.util.Bytes;<a name="line.46"></a>
-<span class="sourceLineNo">047</span>import 
org.apache.hadoop.hbase.util.EnvironmentEdgeManager;<a name="line.47"></a>
-<span class="sourceLineNo">048</span>import 
org.apache.zookeeper.KeeperException;<a name="line.48"></a>
-<span class="sourceLineNo">049</span>import 
org.apache.zookeeper.WatchedEvent;<a name="line.49"></a>
-<span class="sourceLineNo">050</span>import org.apache.zookeeper.Watcher;<a 
name="line.50"></a>
-<span class="sourceLineNo">051</span>import org.apache.zookeeper.ZooKeeper;<a 
name="line.51"></a>
-<span class="sourceLineNo">052</span><a name="line.52"></a>
-<span class="sourceLineNo">053</span>/**<a name="line.53"></a>
-<span class="sourceLineNo">054</span> * This is an example showing how a 
RegionObserver could configured<a name="line.54"></a>
-<span class="sourceLineNo">055</span> * via ZooKeeper in order to control a 
Region compaction, flush, and scan policy.<a name="line.55"></a>
-<span class="sourceLineNo">056</span> *<a name="line.56"></a>
-<span class="sourceLineNo">057</span> * This also demonstrated the use of 
shared<a name="line.57"></a>
-<span class="sourceLineNo">058</span> * {@link 
org.apache.hadoop.hbase.coprocessor.RegionObserver} state.<a name="line.58"></a>
-<span class="sourceLineNo">059</span> * See {@link 
RegionCoprocessorEnvironment#getSharedData()}.<a name="line.59"></a>
-<span class="sourceLineNo">060</span> *<a name="line.60"></a>
-<span class="sourceLineNo">061</span> * This would be useful for an 
incremental backup tool, which would indicate the last<a name="line.61"></a>
-<span class="sourceLineNo">062</span> * time of a successful backup via ZK and 
instruct HBase to not delete data that was<a name="line.62"></a>
-<span class="sourceLineNo">063</span> * inserted since (based on wall clock 
time).<a name="line.63"></a>
-<span class="sourceLineNo">064</span> *<a name="line.64"></a>
-<span class="sourceLineNo">065</span> * This implements 
org.apache.zookeeper.Watcher directly instead of using<a name="line.65"></a>
-<span class="sourceLineNo">066</span> * {@link 
org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher},<a name="line.66"></a>
-<span class="sourceLineNo">067</span> * because RegionObservers come and go 
and currently<a name="line.67"></a>
-<span class="sourceLineNo">068</span> * listeners registered with 
ZooKeeperWatcher cannot be removed.<a name="line.68"></a>
-<span class="sourceLineNo">069</span> */<a name="line.69"></a>
-<span class="sourceLineNo">070</span>public class ZooKeeperScanPolicyObserver 
implements RegionCoprocessor, RegionObserver {<a name="line.70"></a>
-<span class="sourceLineNo">071</span>  @Override<a name="line.71"></a>
-<span class="sourceLineNo">072</span>  public Optional&lt;RegionObserver&gt; 
getRegionObserver() {<a name="line.72"></a>
-<span class="sourceLineNo">073</span>    return Optional.of(this);<a 
name="line.73"></a>
-<span class="sourceLineNo">074</span>  }<a name="line.74"></a>
-<span class="sourceLineNo">075</span><a name="line.75"></a>
-<span class="sourceLineNo">076</span>  // The zk ensemble info is put in hbase 
config xml with given custom key.<a name="line.76"></a>
-<span class="sourceLineNo">077</span>  public static final String 
ZK_ENSEMBLE_KEY = "ZooKeeperScanPolicyObserver.zookeeper.ensemble";<a 
name="line.77"></a>
-<span class="sourceLineNo">078</span>  public static final String 
ZK_SESSION_TIMEOUT_KEY =<a name="line.78"></a>
-<span class="sourceLineNo">079</span>      
"ZooKeeperScanPolicyObserver.zookeeper.session.timeout";<a name="line.79"></a>
-<span class="sourceLineNo">080</span>  public static final int 
ZK_SESSION_TIMEOUT_DEFAULT = 30 * 1000; // 30 secs<a name="line.80"></a>
-<span class="sourceLineNo">081</span>  public static final String node = 
"/backup/example/lastbackup";<a name="line.81"></a>
-<span class="sourceLineNo">082</span>  public static final String zkkey = 
"ZK";<a name="line.82"></a>
-<span class="sourceLineNo">083</span>  private static final Log LOG = 
LogFactory.getLog(ZooKeeperScanPolicyObserver.class);<a name="line.83"></a>
-<span class="sourceLineNo">084</span><a name="line.84"></a>
-<span class="sourceLineNo">085</span>  private ZooKeeper zk = null;<a 
name="line.85"></a>
-<span class="sourceLineNo">086</span><a name="line.86"></a>
-<span class="sourceLineNo">087</span>  /**<a name="line.87"></a>
-<span class="sourceLineNo">088</span>   * Internal watcher that keep "data" up 
to date asynchronously.<a name="line.88"></a>
-<span class="sourceLineNo">089</span>   */<a name="line.89"></a>
-<span class="sourceLineNo">090</span>  private static class ZKWatcher 
implements Watcher {<a name="line.90"></a>
-<span class="sourceLineNo">091</span>    private byte[] data = null;<a 
name="line.91"></a>
-<span class="sourceLineNo">092</span>    private ZooKeeper zk;<a 
name="line.92"></a>
-<span class="sourceLineNo">093</span>    private volatile boolean needSetup = 
true;<a name="line.93"></a>
-<span class="sourceLineNo">094</span>    private volatile long lastSetupTry = 
0;<a name="line.94"></a>
-<span class="sourceLineNo">095</span><a name="line.95"></a>
-<span class="sourceLineNo">096</span>    public ZKWatcher(ZooKeeper zk) {<a 
name="line.96"></a>
-<span class="sourceLineNo">097</span>      this.zk = zk;<a name="line.97"></a>
-<span class="sourceLineNo">098</span>      // trigger the listening<a 
name="line.98"></a>
-<span class="sourceLineNo">099</span>      getData();<a name="line.99"></a>
-<span class="sourceLineNo">100</span>    }<a name="line.100"></a>
-<span class="sourceLineNo">101</span><a name="line.101"></a>
-<span class="sourceLineNo">102</span>    /**<a name="line.102"></a>
-<span class="sourceLineNo">103</span>     * Get the maintained data. In case 
of any ZK exceptions this will retry<a name="line.103"></a>
-<span class="sourceLineNo">104</span>     * establishing the connection (but 
not more than twice/minute).<a name="line.104"></a>
-<span class="sourceLineNo">105</span>     *<a name="line.105"></a>
-<span class="sourceLineNo">106</span>     * getData is on the critical path, 
so make sure it is fast unless there is<a name="line.106"></a>
-<span class="sourceLineNo">107</span>     * a problem (network partion, ZK 
ensemble down, etc)<a name="line.107"></a>
-<span class="sourceLineNo">108</span>     * Make sure at most one (unlucky) 
thread retries and other threads don't pile up<a name="line.108"></a>
-<span class="sourceLineNo">109</span>     * while that threads tries to 
recreate the connection.<a name="line.109"></a>
-<span class="sourceLineNo">110</span>     *<a name="line.110"></a>
-<span class="sourceLineNo">111</span>     * @return the last know version of 
the data<a name="line.111"></a>
-<span class="sourceLineNo">112</span>     */<a name="line.112"></a>
-<span class="sourceLineNo">113</span>    
@edu.umd.cs.findbugs.annotations.SuppressWarnings(value="REC_CATCH_EXCEPTION")<a
 name="line.113"></a>
-<span class="sourceLineNo">114</span>    public byte[] getData() {<a 
name="line.114"></a>
-<span class="sourceLineNo">115</span>      // try at most twice/minute<a 
name="line.115"></a>
-<span class="sourceLineNo">116</span>      if (needSetup &amp;&amp; 
EnvironmentEdgeManager.currentTime() &gt; lastSetupTry + 30000) {<a 
name="line.116"></a>
-<span class="sourceLineNo">117</span>        synchronized (this) {<a 
name="line.117"></a>
-<span class="sourceLineNo">118</span>          // make sure only one thread 
tries to reconnect<a name="line.118"></a>
-<span class="sourceLineNo">119</span>          if (needSetup) {<a 
name="line.119"></a>
-<span class="sourceLineNo">120</span>            needSetup = false;<a 
name="line.120"></a>
-<span class="sourceLineNo">121</span>          } else {<a name="line.121"></a>
-<span class="sourceLineNo">122</span>            return data;<a 
name="line.122"></a>
-<span class="sourceLineNo">123</span>          }<a name="line.123"></a>
-<span class="sourceLineNo">124</span>        }<a name="line.124"></a>
-<span class="sourceLineNo">125</span>        // do this without the lock held 
to avoid threads piling up on this lock,<a name="line.125"></a>
-<span class="sourceLineNo">126</span>        // as it can take a while<a 
name="line.126"></a>
-<span class="sourceLineNo">127</span>        try {<a name="line.127"></a>
-<span class="sourceLineNo">128</span>          LOG.debug("Connecting to 
ZK");<a name="line.128"></a>
-<span class="sourceLineNo">129</span>          // record this attempt<a 
name="line.129"></a>
-<span class="sourceLineNo">130</span>          lastSetupTry = 
EnvironmentEdgeManager.currentTime();<a name="line.130"></a>
-<span class="sourceLineNo">131</span>          if (zk.exists(node, false) != 
null) {<a name="line.131"></a>
-<span class="sourceLineNo">132</span>            data = zk.getData(node, this, 
null);<a name="line.132"></a>
-<span class="sourceLineNo">133</span>            LOG.debug("Read 
synchronously: "+(data == null ? "null" : Bytes.toLong(data)));<a 
name="line.133"></a>
-<span class="sourceLineNo">134</span>          } else {<a name="line.134"></a>
-<span class="sourceLineNo">135</span>            zk.exists(node, this);<a 
name="line.135"></a>
-<span class="sourceLineNo">136</span>          }<a name="line.136"></a>
-<span class="sourceLineNo">137</span>        } catch (Exception x) {<a 
name="line.137"></a>
-<span class="sourceLineNo">138</span>          // try again if this fails<a 
name="line.138"></a>
-<span class="sourceLineNo">139</span>          needSetup = true;<a 
name="line.139"></a>
-<span class="sourceLineNo">140</span>        }<a name="line.140"></a>
-<span class="sourceLineNo">141</span>      }<a name="line.141"></a>
-<span class="sourceLineNo">142</span>      return data;<a name="line.142"></a>
-<span class="sourceLineNo">143</span>    }<a name="line.143"></a>
-<span class="sourceLineNo">144</span><a name="line.144"></a>
-<span class="sourceLineNo">145</span>    @Override<a name="line.145"></a>
-<span class="sourceLineNo">146</span>    public void process(WatchedEvent 
event) {<a name="line.146"></a>
-<span class="sourceLineNo">147</span>      switch (event.getType()) {<a 
name="line.147"></a>
-<span class="sourceLineNo">148</span>        case NodeDataChanged:<a 
name="line.148"></a>
-<span class="sourceLineNo">149</span>        case NodeCreated:<a 
name="line.149"></a>
-<span class="sourceLineNo">150</span>          try {<a name="line.150"></a>
-<span class="sourceLineNo">151</span>            // get data and re-watch<a 
name="line.151"></a>
-<span class="sourceLineNo">152</span>            data = zk.getData(node, this, 
null);<a name="line.152"></a>
-<span class="sourceLineNo">153</span>            LOG.debug("Read 
asynchronously: " + (data == null ? "null" : Bytes.toLong(data)));<a 
name="line.153"></a>
-<span class="sourceLineNo">154</span>          } catch (InterruptedException 
ix) {<a name="line.154"></a>
-<span class="sourceLineNo">155</span>          } catch (KeeperException kx) 
{<a name="line.155"></a>
-<span class="sourceLineNo">156</span>            needSetup = true;<a 
name="line.156"></a>
-<span class="sourceLineNo">157</span>          }<a name="line.157"></a>
-<span class="sourceLineNo">158</span>          break;<a name="line.158"></a>
-<span class="sourceLineNo">159</span><a name="line.159"></a>
-<span class="sourceLineNo">160</span>        case NodeDeleted:<a 
name="line.160"></a>
-<span class="sourceLineNo">161</span>          try {<a name="line.161"></a>
-<span class="sourceLineNo">162</span>            // just re-watch<a 
name="line.162"></a>
-<span class="sourceLineNo">163</span>            zk.exists(node, this);<a 
name="line.163"></a>
-<span class="sourceLineNo">164</span>            data = null;<a 
name="line.164"></a>
-<span class="sourceLineNo">165</span>          } catch (InterruptedException 
ix) {<a name="line.165"></a>
-<span class="sourceLineNo">166</span>          } catch (KeeperException kx) 
{<a name="line.166"></a>
-<span class="sourceLineNo">167</span>            needSetup = true;<a 
name="line.167"></a>
-<span class="sourceLineNo">168</span>          }<a name="line.168"></a>
-<span class="sourceLineNo">169</span>          break;<a name="line.169"></a>
-<span class="sourceLineNo">170</span><a name="line.170"></a>
-<span class="sourceLineNo">171</span>        default:<a name="line.171"></a>
-<span class="sourceLineNo">172</span>          // ignore<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>  }<a name="line.175"></a>
-<span class="sourceLineNo">176</span><a name="line.176"></a>
-<span class="sourceLineNo">177</span>  @Override<a name="line.177"></a>
-<span class="sourceLineNo">178</span>  public void 
start(CoprocessorEnvironment e) throws IOException {<a name="line.178"></a>
-<span class="sourceLineNo">179</span>    RegionCoprocessorEnvironment re = 
(RegionCoprocessorEnvironment) e;<a name="line.179"></a>
-<span class="sourceLineNo">180</span>    if 
(!re.getSharedData().containsKey(zkkey)) {<a name="line.180"></a>
-<span class="sourceLineNo">181</span>      // there is a short race here<a 
name="line.181"></a>
-<span class="sourceLineNo">182</span>      // in the worst case we create a 
watcher that will be notified once<a name="line.182"></a>
-<span class="sourceLineNo">183</span>      String ensemble = 
re.getConfiguration().get(ZK_ENSEMBLE_KEY);<a name="line.183"></a>
-<span class="sourceLineNo">184</span>      int sessionTimeout = 
re.getConfiguration().getInt(ZK_SESSION_TIMEOUT_KEY,<a name="line.184"></a>
-<span class="sourceLineNo">185</span>          ZK_SESSION_TIMEOUT_DEFAULT);<a 
name="line.185"></a>
-<span class="sourceLineNo">186</span>      this.zk = new ZooKeeper(ensemble, 
sessionTimeout, null);<a name="line.186"></a>
-<span class="sourceLineNo">187</span>      
re.getSharedData().putIfAbsent(zkkey, new ZKWatcher(zk));<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><a name="line.190"></a>
-<span class="sourceLineNo">191</span>  @Override<a name="line.191"></a>
-<span class="sourceLineNo">192</span>  public void stop(CoprocessorEnvironment 
env) throws IOException {<a name="line.192"></a>
-<span class="sourceLineNo">193</span>    if (this.zk != null) {<a 
name="line.193"></a>
-<span class="sourceLineNo">194</span>      try {<a name="line.194"></a>
-<span class="sourceLineNo">195</span>        this.zk.close();<a 
name="line.195"></a>
-<span class="sourceLineNo">196</span>      } catch (InterruptedException e) 
{<a name="line.196"></a>
-<span class="sourceLineNo">197</span>        LOG.error("Excepion while closing 
the ZK connection!", e);<a name="line.197"></a>
-<span class="sourceLineNo">198</span>      }<a name="line.198"></a>
-<span class="sourceLineNo">199</span>    }<a name="line.199"></a>
-<span class="sourceLineNo">200</span>  }<a name="line.200"></a>
-<span class="sourceLineNo">201</span><a name="line.201"></a>
-<span class="sourceLineNo">202</span>  protected ScanInfo getScanInfo(Store 
store, RegionCoprocessorEnvironment e) {<a name="line.202"></a>
-<span class="sourceLineNo">203</span>    byte[] data = ((ZKWatcher) 
e.getSharedData().get(zkkey)).getData();<a name="line.203"></a>
-<span class="sourceLineNo">204</span>    if (data == null) {<a 
name="line.204"></a>
-<span class="sourceLineNo">205</span>      return null;<a name="line.205"></a>
-<span class="sourceLineNo">206</span>    }<a name="line.206"></a>
-<span class="sourceLineNo">207</span>    ScanInfo oldSI = ((HStore) 
store).getScanInfo();<a name="line.207"></a>
-<span class="sourceLineNo">208</span>    if (oldSI.getTtl() == Long.MAX_VALUE) 
{<a name="line.208"></a>
-<span class="sourceLineNo">209</span>      return null;<a name="line.209"></a>
-<span class="sourceLineNo">210</span>    }<a name="line.210"></a>
-<span class="sourceLineNo">211</span>    long ttl = 
Math.max(EnvironmentEdgeManager.currentTime() - Bytes.toLong(data), 
oldSI.getTtl());<a name="line.211"></a>
-<span class="sourceLineNo">212</span>    return new 
ScanInfo(oldSI.getConfiguration(), store.getColumnFamilyDescriptor(), ttl,<a 
name="line.212"></a>
-<span class="sourceLineNo">213</span>        oldSI.getTimeToPurgeDeletes(), 
oldSI.getComparator());<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>  @Override<a name="line.216"></a>
-<span class="sourceLineNo">217</span>  public InternalScanner 
preFlushScannerOpen(ObserverContext&lt;RegionCoprocessorEnvironment&gt; c,<a 
name="line.217"></a>
-<span class="sourceLineNo">218</span>      Store store, 
List&lt;KeyValueScanner&gt; scanners, InternalScanner s, long readPoint)<a 
name="line.218"></a>
-<span class="sourceLineNo">219</span>      throws IOException {<a 
name="line.219"></a>
-<span class="sourceLineNo">220</span>    ScanInfo scanInfo = 
getScanInfo(store, c.getEnvironment());<a name="line.220"></a>
-<span class="sourceLineNo">221</span>    if (scanInfo == null) {<a 
name="line.221"></a>
-<span class="sourceLineNo">222</span>      // take default action<a 
name="line.222"></a>
-<span class="sourceLineNo">223</span>      return null;<a name="line.223"></a>
-<span class="sourceLineNo">224</span>    }<a name="line.224"></a>
-<span class="sourceLineNo">225</span>    return new StoreScanner((HStore) 
store, scanInfo, OptionalInt.empty(), scanners,<a name="line.225"></a>
-<span class="sourceLineNo">226</span>        ScanType.COMPACT_RETAIN_DELETES, 
store.getSmallestReadPoint(), HConstants.OLDEST_TIMESTAMP);<a 
name="line.226"></a>
-<span class="sourceLineNo">227</span>  }<a name="line.227"></a>
-<span class="sourceLineNo">228</span><a name="line.228"></a>
-<span class="sourceLineNo">229</span>  @Override<a name="line.229"></a>
-<span class="sourceLineNo">230</span>  public InternalScanner 
preCompactScannerOpen(ObserverContext&lt;RegionCoprocessorEnvironment&gt; c,<a 
name="line.230"></a>
-<span class="sourceLineNo">231</span>      Store store, List&lt;? extends 
KeyValueScanner&gt; scanners, ScanType scanType, long earliestPutTs,<a 
name="line.231"></a>
-<span class="sourceLineNo">232</span>      InternalScanner s, 
CompactionLifeCycleTracker tracker, CompactionRequest request,<a 
name="line.232"></a>
-<span class="sourceLineNo">233</span>      long readPoint) throws IOException 
{<a name="line.233"></a>
-<span class="sourceLineNo">234</span>    ScanInfo scanInfo = 
getScanInfo(store, c.getEnvironment());<a name="line.234"></a>
-<span class="sourceLineNo">235</span>    if (scanInfo == null) {<a 
name="line.235"></a>
-<span class="sourceLineNo">236</span>      // take default action<a 
name="line.236"></a>
-<span class="sourceLineNo">237</span>      return null;<a name="line.237"></a>
-<span class="sourceLineNo">238</span>    }<a name="line.238"></a>
-<span class="sourceLineNo">239</span>    return new StoreScanner((HStore) 
store, scanInfo, OptionalInt.empty(), scanners, scanType,<a name="line.239"></a>
-<span class="sourceLineNo">240</span>        store.getSmallestReadPoint(), 
earliestPutTs);<a name="line.240"></a>
-<span class="sourceLineNo">241</span>  }<a name="line.241"></a>
-<span class="sourceLineNo">242</span><a name="line.242"></a>
-<span class="sourceLineNo">243</span>  @Override<a name="line.243"></a>
-<span class="sourceLineNo">244</span>  public KeyValueScanner 
preStoreScannerOpen(ObserverContext&lt;RegionCoprocessorEnvironment&gt; c,<a 
name="line.244"></a>
-<span class="sourceLineNo">245</span>      Store store, Scan scan, 
NavigableSet&lt;byte[]&gt; targetCols, KeyValueScanner s, long readPoint)<a 
name="line.245"></a>
-<span class="sourceLineNo">246</span>      throws IOException {<a 
name="line.246"></a>
-<span class="sourceLineNo">247</span>    ScanInfo scanInfo = 
getScanInfo(store, c.getEnvironment());<a name="line.247"></a>
-<span class="sourceLineNo">248</span>    if (scanInfo == null) {<a 
name="line.248"></a>
-<span class="sourceLineNo">249</span>      // take default action<a 
name="line.249"></a>
-<span class="sourceLineNo">250</span>      return null;<a name="line.250"></a>
-<span class="sourceLineNo">251</span>    }<a name="line.251"></a>
-<span class="sourceLineNo">252</span>    return new StoreScanner((HStore) 
store, scanInfo, scan, targetCols,<a name="line.252"></a>
-<span class="sourceLineNo">253</span>        ((HStore) 
store).getHRegion().getReadPoint(IsolationLevel.READ_COMMITTED));<a 
name="line.253"></a>
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-<span class="sourceLineNo">255</span>}<a name="line.255"></a>
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-</div>
-</body>
-</html>

http://git-wip-us.apache.org/repos/asf/hbase-site/blob/7816cbde/devapidocs/src-html/org/apache/hadoop/hbase/coprocessor/example/ZooKeeperScanPolicyObserver.html
----------------------------------------------------------------------
diff --git 
a/devapidocs/src-html/org/apache/hadoop/hbase/coprocessor/example/ZooKeeperScanPolicyObserver.html
 
b/devapidocs/src-html/org/apache/hadoop/hbase/coprocessor/example/ZooKeeperScanPolicyObserver.html
index cd98846..eef9d8d 100644
--- 
a/devapidocs/src-html/org/apache/hadoop/hbase/coprocessor/example/ZooKeeperScanPolicyObserver.html
+++ 
b/devapidocs/src-html/org/apache/hadoop/hbase/coprocessor/example/ZooKeeperScanPolicyObserver.html
@@ -6,7 +6,7 @@
 </head>
 <body>
 <div class="sourceContainer">
-<pre><span class="sourceLineNo">001</span>/*<a name="line.1"></a>
+<pre><span class="sourceLineNo">001</span>/**<a name="line.1"></a>
 <span class="sourceLineNo">002</span> * Copyright The Apache Software 
Foundation<a name="line.2"></a>
 <span class="sourceLineNo">003</span> *<a name="line.3"></a>
 <span class="sourceLineNo">004</span> * Licensed to the Apache Software 
Foundation (ASF) under one or more<a name="line.4"></a>
@@ -28,239 +28,185 @@
 <span class="sourceLineNo">020</span><a name="line.20"></a>
 <span class="sourceLineNo">021</span>import java.io.IOException;<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.NavigableSet;<a 
name="line.23"></a>
-<span class="sourceLineNo">024</span>import java.util.Optional;<a 
name="line.24"></a>
-<span class="sourceLineNo">025</span>import java.util.OptionalInt;<a 
name="line.25"></a>
-<span class="sourceLineNo">026</span><a name="line.26"></a>
-<span class="sourceLineNo">027</span>import org.apache.commons.logging.Log;<a 
name="line.27"></a>
-<span class="sourceLineNo">028</span>import 
org.apache.commons.logging.LogFactory;<a name="line.28"></a>
-<span class="sourceLineNo">029</span>import 
org.apache.hadoop.hbase.CoprocessorEnvironment;<a name="line.29"></a>
-<span class="sourceLineNo">030</span>import 
org.apache.hadoop.hbase.HConstants;<a name="line.30"></a>
-<span class="sourceLineNo">031</span>import 
org.apache.hadoop.hbase.client.IsolationLevel;<a name="line.31"></a>
-<span class="sourceLineNo">032</span>import 
org.apache.hadoop.hbase.client.Scan;<a name="line.32"></a>
+<span class="sourceLineNo">023</span>import java.util.Optional;<a 
name="line.23"></a>
+<span class="sourceLineNo">024</span>import java.util.OptionalLong;<a 
name="line.24"></a>
+<span class="sourceLineNo">025</span><a name="line.25"></a>
+<span class="sourceLineNo">026</span>import 
org.apache.curator.framework.CuratorFramework;<a name="line.26"></a>
+<span class="sourceLineNo">027</span>import 
org.apache.curator.framework.CuratorFrameworkFactory;<a name="line.27"></a>
+<span class="sourceLineNo">028</span>import 
org.apache.curator.framework.recipes.cache.ChildData;<a name="line.28"></a>
+<span class="sourceLineNo">029</span>import 
org.apache.curator.framework.recipes.cache.NodeCache;<a name="line.29"></a>
+<span class="sourceLineNo">030</span>import 
org.apache.curator.retry.RetryForever;<a name="line.30"></a>
+<span class="sourceLineNo">031</span>import org.apache.hadoop.hbase.Cell;<a 
name="line.31"></a>
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org.apache.hadoop.hbase.CoprocessorEnvironment;<a name="line.32"></a>
 <span class="sourceLineNo">033</span>import 
org.apache.hadoop.hbase.coprocessor.ObserverContext;<a name="line.33"></a>
 <span class="sourceLineNo">034</span>import 
org.apache.hadoop.hbase.coprocessor.RegionCoprocessor;<a name="line.34"></a>
 <span class="sourceLineNo">035</span>import 
org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;<a 
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 <span class="sourceLineNo">036</span>import 
org.apache.hadoop.hbase.coprocessor.RegionObserver;<a name="line.36"></a>
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org.apache.hadoop.hbase.regionserver.HStore;<a name="line.37"></a>
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org.apache.hadoop.hbase.regionserver.InternalScanner;<a name="line.38"></a>
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org.apache.hadoop.hbase.regionserver.KeyValueScanner;<a name="line.39"></a>
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org.apache.hadoop.hbase.regionserver.ScanInfo;<a name="line.40"></a>
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org.apache.hadoop.hbase.regionserver.ScanType;<a name="line.41"></a>
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org.apache.hadoop.hbase.regionserver.Store;<a name="line.42"></a>
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org.apache.hadoop.hbase.regionserver.StoreScanner;<a name="line.43"></a>
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org.apache.hadoop.hbase.regionserver.compactions.CompactionLifeCycleTracker;<a 
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org.apache.hadoop.hbase.regionserver.compactions.CompactionRequest;<a 
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org.apache.hadoop.hbase.util.Bytes;<a name="line.46"></a>
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org.apache.hadoop.hbase.util.EnvironmentEdgeManager;<a name="line.47"></a>
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org.apache.zookeeper.KeeperException;<a name="line.48"></a>
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-<span class="sourceLineNo">053</span>/**<a name="line.53"></a>
-<span class="sourceLineNo">054</span> * This is an example showing how a 
RegionObserver could configured<a name="line.54"></a>
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Region compaction, flush, and scan policy.<a name="line.55"></a>
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-<span class="sourceLineNo">057</span> * This also demonstrated the use of 
shared<a name="line.57"></a>
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org.apache.hadoop.hbase.coprocessor.RegionObserver} state.<a name="line.58"></a>
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RegionCoprocessorEnvironment#getSharedData()}.<a name="line.59"></a>
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-<span class="sourceLineNo">061</span> * This would be useful for an 
incremental backup tool, which would indicate the last<a name="line.61"></a>
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instruct HBase to not delete data that was<a name="line.62"></a>
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time).<a name="line.63"></a>
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org.apache.zookeeper.Watcher directly instead of using<a name="line.65"></a>
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org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher},<a name="line.66"></a>
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and currently<a name="line.67"></a>
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ZooKeeperWatcher cannot be removed.<a name="line.68"></a>
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config xml with given custom key.<a name="line.76"></a>
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ZK_ENSEMBLE_KEY = "ZooKeeperScanPolicyObserver.zookeeper.ensemble";<a 
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ZK_SESSION_TIMEOUT_KEY =<a name="line.78"></a>
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"ZooKeeperScanPolicyObserver.zookeeper.session.timeout";<a name="line.79"></a>
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ZK_SESSION_TIMEOUT_DEFAULT = 30 * 1000; // 30 secs<a name="line.80"></a>
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"/backup/example/lastbackup";<a name="line.81"></a>
-<span class="sourceLineNo">082</span>  public static final String zkkey = 
"ZK";<a name="line.82"></a>
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LogFactory.getLog(ZooKeeperScanPolicyObserver.class);<a name="line.83"></a>
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org.apache.hadoop.hbase.regionserver.InternalScanner;<a name="line.37"></a>
+<span class="sourceLineNo">038</span>import 
org.apache.hadoop.hbase.regionserver.ScanType;<a name="line.38"></a>
+<span class="sourceLineNo">039</span>import 
org.apache.hadoop.hbase.regionserver.ScannerContext;<a name="line.39"></a>
+<span class="sourceLineNo">040</span>import 
org.apache.hadoop.hbase.regionserver.Store;<a name="line.40"></a>
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org.apache.hadoop.hbase.regionserver.compactions.CompactionLifeCycleTracker;<a 
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+<span class="sourceLineNo">042</span>import 
org.apache.hadoop.hbase.regionserver.compactions.CompactionRequest;<a 
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org.apache.hadoop.hbase.util.Bytes;<a name="line.43"></a>
+<span class="sourceLineNo">044</span><a name="line.44"></a>
+<span class="sourceLineNo">045</span>/**<a name="line.45"></a>
+<span class="sourceLineNo">046</span> * This is an example showing how a 
RegionObserver could configured via ZooKeeper in order to<a name="line.46"></a>
+<span class="sourceLineNo">047</span> * control a Region compaction, flush, 
and scan policy. This also demonstrated the use of shared<a name="line.47"></a>
+<span class="sourceLineNo">048</span> * {@link 
org.apache.hadoop.hbase.coprocessor.RegionObserver} state. See<a 
name="line.48"></a>
+<span class="sourceLineNo">049</span> * {@link 
RegionCoprocessorEnvironment#getSharedData()}.<a name="line.49"></a>
+<span class="sourceLineNo">050</span> * &lt;p&gt;<a name="line.50"></a>
+<span class="sourceLineNo">051</span> * This would be useful for an 
incremental backup tool, which would indicate the last time of a<a 
name="line.51"></a>
+<span class="sourceLineNo">052</span> * successful backup via ZK and instruct 
HBase that to safely delete the data which has already been<a 
name="line.52"></a>
+<span class="sourceLineNo">053</span> * backup.<a name="line.53"></a>
+<span class="sourceLineNo">054</span> */<a name="line.54"></a>
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implements RegionCoprocessor, RegionObserver {<a name="line.55"></a>
+<span class="sourceLineNo">056</span><a name="line.56"></a>
+<span class="sourceLineNo">057</span>  @Override<a name="line.57"></a>
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getRegionObserver() {<a name="line.58"></a>
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name="line.59"></a>
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+<span class="sourceLineNo">061</span><a name="line.61"></a>
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config xml with given custom key.<a name="line.62"></a>
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ZK_ENSEMBLE_KEY = "ZooKeeperScanPolicyObserver.zookeeper.ensemble";<a 
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ZK_SESSION_TIMEOUT_KEY =<a name="line.64"></a>
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"ZooKeeperScanPolicyObserver.zookeeper.session.timeout";<a name="line.65"></a>
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ZK_SESSION_TIMEOUT_DEFAULT = 30 * 1000; // 30 secs<a name="line.66"></a>
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"/backup/example/lastbackup";<a name="line.67"></a>
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"ZK";<a name="line.68"></a>
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to date asynchronously.<a name="line.73"></a>
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{<a name="line.75"></a>
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 <span class="sourceLineNo">084</span><a name="line.84"></a>
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to date asynchronously.<a name="line.88"></a>
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0;<a name="line.94"></a>
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of any ZK exceptions this will retry<a name="line.103"></a>
-<span class="sourceLineNo">104</span>     * establishing the connection (but 
not more than twice/minute).<a name="line.104"></a>
-<span class="sourceLineNo">105</span>     *<a name="line.105"></a>
-<span class="sourceLineNo">106</span>     * getData is on the critical path, 
so make sure it is fast unless there is<a name="line.106"></a>
-<span class="sourceLineNo">107</span>     * a problem (network partion, ZK 
ensemble down, etc)<a name="line.107"></a>
-<span class="sourceLineNo">108</span>     * Make sure at most one (unlucky) 
thread retries and other threads don't pile up<a name="line.108"></a>
-<span class="sourceLineNo">109</span>     * while that threads tries to 
recreate the connection.<a name="line.109"></a>
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the data<a name="line.111"></a>
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@edu.umd.cs.findbugs.annotations.SuppressWarnings(value="REC_CATCH_EXCEPTION")<a
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EnvironmentEdgeManager.currentTime() &gt; lastSetupTry + 30000) {<a 
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int sessionTimeout) {<a name="line.87"></a>
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Exception {<a name="line.92"></a>
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+<span class="sourceLineNo">094</span>          
CuratorFrameworkFactory.builder().connectString(ensemble).sessionTimeoutMs(sessionTimeout)<a
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RetryForever(1000)).canBeReadOnly(true).build();<a name="line.95"></a>
+<span class="sourceLineNo">096</span>      client.start();<a 
name="line.96"></a>
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NODE);<a name="line.97"></a>
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name="line.98"></a>
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+<span class="sourceLineNo">100</span><a name="line.100"></a>
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renv.getSharedData().get(ZKKEY)).release();<a name="line.157"></a>
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Long.BYTES) {<a name="line.166"></a>
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OptionalLong.of(Bytes.toLong(bytes));<a name="line.169"></a>
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wrap(InternalScanner scanner) {<a name="line.172"></a>
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getExpireBefore();<a name="line.173"></a>
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name="line.174"></a>
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optExpireBefore.getAsLong();<a name="line.177"></a>
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next(List&lt;Cell&gt; result, ScannerContext scannerContext) throws IOException 
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scanner.next(result, scannerContext);<a name="line.182"></a>
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c.getTimestamp() &lt; expireBefore);<a name="line.183"></a>
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preFlush(ObserverContext&lt;RegionCoprocessorEnvironment&gt; c, Store store,<a 
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IOException {<a name="line.191"></a>
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preCompact(ObserverContext&lt;RegionCoprocessorEnvironment&gt; c, Store 
store,<a name="line.196"></a>
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scanType, CompactionLifeCycleTracker tracker,<a name="line.197"></a>
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IOException {<a name="line.198"></a>
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e.getSharedData().get(zkkey)).getData();<a name="line.203"></a>
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Math.max(EnvironmentEdgeManager.currentTime() - Bytes.toLong(data), 
oldSI.getTtl());<a name="line.211"></a>
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ScanInfo(oldSI.getConfiguration(), store.getColumnFamilyDescriptor(), ttl,<a 
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oldSI.getComparator());<a name="line.213"></a>
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preFlushScannerOpen(ObserverContext&lt;RegionCoprocessorEnvironment&gt; c,<a 
name="line.217"></a>
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List&lt;KeyValueScanner&gt; scanners, InternalScanner s, long readPoint)<a 
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store.getSmallestReadPoint(), HConstants.OLDEST_TIMESTAMP);<a 
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store, scanInfo, OptionalInt.empty(), scanners, scanType,<a name="line.239"></a>
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earliestPutTs);<a name="line.240"></a>
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preStoreScannerOpen(ObserverContext&lt;RegionCoprocessorEnvironment&gt; c,<a 
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store).getHRegion().getReadPoint(IsolationLevel.READ_COMMITTED));<a 
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[30/51] [partial] hbase-site git commit: Published site at .

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