http://git-wip-us.apache.org/repos/asf/hbase-site/blob/e11cf2cb/devapidocs/src-html/org/apache/hadoop/hbase/master/RegionServerTracker.html
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b/devapidocs/src-html/org/apache/hadoop/hbase/master/RegionServerTracker.html
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---
a/devapidocs/src-html/org/apache/hadoop/hbase/master/RegionServerTracker.html
+++
b/devapidocs/src-html/org/apache/hadoop/hbase/master/RegionServerTracker.html
@@ -7,179 +7,190 @@
<body>
<div class="sourceContainer">
<pre><span class="sourceLineNo">001</span>/**<a name="line.1"></a>
-<span class="sourceLineNo">002</span> *<a name="line.2"></a>
-<span class="sourceLineNo">003</span> * Licensed to the Apache Software
Foundation (ASF) under one<a name="line.3"></a>
-<span class="sourceLineNo">004</span> * or more contributor license
agreements. See the NOTICE file<a name="line.4"></a>
-<span class="sourceLineNo">005</span> * distributed with this work for
additional information<a name="line.5"></a>
-<span class="sourceLineNo">006</span> * regarding copyright ownership. The
ASF licenses this file<a name="line.6"></a>
-<span class="sourceLineNo">007</span> * 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<a name="line.8"></a>
-<span class="sourceLineNo">009</span> * with the License. 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,<a name="line.14"></a>
-<span class="sourceLineNo">015</span> * WITHOUT WARRANTIES OR CONDITIONS OF
ANY KIND, either express or implied.<a name="line.15"></a>
-<span class="sourceLineNo">016</span> * See the License for the specific
language governing permissions and<a name="line.16"></a>
-<span class="sourceLineNo">017</span> * limitations 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.master;<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.io.InterruptedIOException;<a
name="line.22"></a>
-<span class="sourceLineNo">023</span>import java.util.ArrayList;<a
name="line.23"></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.master;<a
name="line.18"></a>
+<span class="sourceLineNo">019</span><a name="line.19"></a>
+<span class="sourceLineNo">020</span>import java.io.IOException;<a
name="line.20"></a>
+<span class="sourceLineNo">021</span>import java.io.InterruptedIOException;<a
name="line.21"></a>
+<span class="sourceLineNo">022</span>import java.util.HashSet;<a
name="line.22"></a>
+<span class="sourceLineNo">023</span>import java.util.Iterator;<a
name="line.23"></a>
<span class="sourceLineNo">024</span>import java.util.List;<a
name="line.24"></a>
-<span class="sourceLineNo">025</span>import java.util.NavigableMap;<a
name="line.25"></a>
-<span class="sourceLineNo">026</span>import java.util.TreeMap;<a
name="line.26"></a>
-<span class="sourceLineNo">027</span><a name="line.27"></a>
-<span class="sourceLineNo">028</span>import
org.apache.hadoop.hbase.ServerName;<a name="line.28"></a>
-<span class="sourceLineNo">029</span>import
org.apache.hadoop.hbase.zookeeper.ZKListener;<a name="line.29"></a>
-<span class="sourceLineNo">030</span>import
org.apache.hadoop.hbase.zookeeper.ZKUtil;<a name="line.30"></a>
-<span class="sourceLineNo">031</span>import
org.apache.hadoop.hbase.zookeeper.ZKWatcher;<a name="line.31"></a>
-<span class="sourceLineNo">032</span>import
org.apache.hadoop.hbase.zookeeper.ZNodePaths;<a name="line.32"></a>
-<span class="sourceLineNo">033</span>import
org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;<a name="line.33"></a>
-<span class="sourceLineNo">034</span>import
org.apache.hadoop.hbase.shaded.protobuf.generated.HBaseProtos.RegionServerInfo;<a
name="line.34"></a>
-<span class="sourceLineNo">035</span>import
org.apache.yetus.audience.InterfaceAudience;<a name="line.35"></a>
-<span class="sourceLineNo">036</span>import
org.apache.zookeeper.KeeperException;<a name="line.36"></a>
-<span class="sourceLineNo">037</span>import org.slf4j.Logger;<a
name="line.37"></a>
-<span class="sourceLineNo">038</span>import org.slf4j.LoggerFactory;<a
name="line.38"></a>
-<span class="sourceLineNo">039</span><a name="line.39"></a>
-<span class="sourceLineNo">040</span>/**<a name="line.40"></a>
-<span class="sourceLineNo">041</span> * Tracks the online region servers via
ZK.<a name="line.41"></a>
-<span class="sourceLineNo">042</span> *<a name="line.42"></a>
-<span class="sourceLineNo">043</span> * <p>Handling of new RSs checking
in is done via RPC. This class<a name="line.43"></a>
-<span class="sourceLineNo">044</span> * is only responsible for watching for
expired nodes. It handles<a name="line.44"></a>
-<span class="sourceLineNo">045</span> * listening for changes in the RS node
list and watching each node.<a name="line.45"></a>
-<span class="sourceLineNo">046</span> *<a name="line.46"></a>
-<span class="sourceLineNo">047</span> * <p>If an RS node gets deleted,
this automatically handles calling of<a name="line.47"></a>
-<span class="sourceLineNo">048</span> * {@link
ServerManager#expireServer(ServerName)}<a name="line.48"></a>
-<span class="sourceLineNo">049</span> */<a name="line.49"></a>
-<span class="sourceLineNo">050</span>@InterfaceAudience.Private<a
name="line.50"></a>
-<span class="sourceLineNo">051</span>public class RegionServerTracker extends
ZKListener {<a name="line.51"></a>
-<span class="sourceLineNo">052</span> private static final Logger LOG =
LoggerFactory.getLogger(RegionServerTracker.class);<a name="line.52"></a>
-<span class="sourceLineNo">053</span> private final
NavigableMap<ServerName, RegionServerInfo> regionServers = new
TreeMap<>();<a name="line.53"></a>
-<span class="sourceLineNo">054</span> private ServerManager serverManager;<a
name="line.54"></a>
-<span class="sourceLineNo">055</span> private MasterServices server;<a
name="line.55"></a>
-<span class="sourceLineNo">056</span><a name="line.56"></a>
-<span class="sourceLineNo">057</span> public RegionServerTracker(ZKWatcher
watcher,<a name="line.57"></a>
-<span class="sourceLineNo">058</span> MasterServices server,
ServerManager serverManager) {<a name="line.58"></a>
-<span class="sourceLineNo">059</span> super(watcher);<a name="line.59"></a>
-<span class="sourceLineNo">060</span> this.server = server;<a
name="line.60"></a>
-<span class="sourceLineNo">061</span> this.serverManager = serverManager;<a
name="line.61"></a>
-<span class="sourceLineNo">062</span> }<a name="line.62"></a>
-<span class="sourceLineNo">063</span><a name="line.63"></a>
-<span class="sourceLineNo">064</span> /**<a name="line.64"></a>
-<span class="sourceLineNo">065</span> * Starts the tracking of online
RegionServers.<a name="line.65"></a>
-<span class="sourceLineNo">066</span> *<a name="line.66"></a>
-<span class="sourceLineNo">067</span> * <p>All RSs will be tracked
after this method is called.<a name="line.67"></a>
-<span class="sourceLineNo">068</span> *<a name="line.68"></a>
-<span class="sourceLineNo">069</span> * @throws KeeperException<a
name="line.69"></a>
-<span class="sourceLineNo">070</span> * @throws IOException<a
name="line.70"></a>
-<span class="sourceLineNo">071</span> */<a name="line.71"></a>
-<span class="sourceLineNo">072</span> public void start() throws
KeeperException, IOException {<a name="line.72"></a>
-<span class="sourceLineNo">073</span> watcher.registerListener(this);<a
name="line.73"></a>
-<span class="sourceLineNo">074</span> List<String> servers =<a
name="line.74"></a>
-<span class="sourceLineNo">075</span>
ZKUtil.listChildrenAndWatchThem(watcher, watcher.getZNodePaths().rsZNode);<a
name="line.75"></a>
-<span class="sourceLineNo">076</span> refresh(servers);<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> private void refresh(final
List<String> servers) throws IOException {<a name="line.79"></a>
-<span class="sourceLineNo">080</span> synchronized(this.regionServers) {<a
name="line.80"></a>
-<span class="sourceLineNo">081</span> this.regionServers.clear();<a
name="line.81"></a>
-<span class="sourceLineNo">082</span> for (String n: servers) {<a
name="line.82"></a>
-<span class="sourceLineNo">083</span> ServerName sn =
ServerName.parseServerName(ZKUtil.getNodeName(n));<a name="line.83"></a>
-<span class="sourceLineNo">084</span> if (regionServers.get(sn) ==
null) {<a name="line.84"></a>
-<span class="sourceLineNo">085</span> RegionServerInfo.Builder
rsInfoBuilder = RegionServerInfo.newBuilder();<a name="line.85"></a>
-<span class="sourceLineNo">086</span> try {<a name="line.86"></a>
-<span class="sourceLineNo">087</span> String nodePath =
ZNodePaths.joinZNode(watcher.getZNodePaths().rsZNode, n);<a name="line.87"></a>
-<span class="sourceLineNo">088</span> byte[] data =
ZKUtil.getData(watcher, nodePath);<a name="line.88"></a>
-<span class="sourceLineNo">089</span> if (data != null &&
data.length > 0 && ProtobufUtil.isPBMagicPrefix(data)) {<a
name="line.89"></a>
-<span class="sourceLineNo">090</span> int magicLen =
ProtobufUtil.lengthOfPBMagic();<a name="line.90"></a>
-<span class="sourceLineNo">091</span>
ProtobufUtil.mergeFrom(rsInfoBuilder, data, magicLen, data.length -
magicLen);<a name="line.91"></a>
-<span class="sourceLineNo">092</span> }<a name="line.92"></a>
-<span class="sourceLineNo">093</span> if (LOG.isTraceEnabled()) {<a
name="line.93"></a>
-<span class="sourceLineNo">094</span> LOG.trace("Added tracking
of RS " + nodePath);<a name="line.94"></a>
-<span class="sourceLineNo">095</span> }<a name="line.95"></a>
-<span class="sourceLineNo">096</span> } catch (KeeperException e) {<a
name="line.96"></a>
-<span class="sourceLineNo">097</span> LOG.warn("Get Rs info port
from ephemeral node", e);<a name="line.97"></a>
-<span class="sourceLineNo">098</span> } catch (IOException e) {<a
name="line.98"></a>
-<span class="sourceLineNo">099</span> LOG.warn("Illegal data from
ephemeral node", e);<a name="line.99"></a>
-<span class="sourceLineNo">100</span> } catch (InterruptedException
e) {<a name="line.100"></a>
-<span class="sourceLineNo">101</span> throw new
InterruptedIOException();<a name="line.101"></a>
-<span class="sourceLineNo">102</span> }<a name="line.102"></a>
-<span class="sourceLineNo">103</span> this.regionServers.put(sn,
rsInfoBuilder.build());<a name="line.103"></a>
-<span class="sourceLineNo">104</span> }<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> }<a name="line.107"></a>
-<span class="sourceLineNo">108</span><a name="line.108"></a>
-<span class="sourceLineNo">109</span> private void remove(final ServerName
sn) {<a name="line.109"></a>
-<span class="sourceLineNo">110</span> synchronized(this.regionServers) {<a
name="line.110"></a>
-<span class="sourceLineNo">111</span> this.regionServers.remove(sn);<a
name="line.111"></a>
-<span class="sourceLineNo">112</span> }<a name="line.112"></a>
-<span class="sourceLineNo">113</span> }<a name="line.113"></a>
-<span class="sourceLineNo">114</span><a name="line.114"></a>
-<span class="sourceLineNo">115</span> @Override<a name="line.115"></a>
-<span class="sourceLineNo">116</span> public void nodeCreated(String path)
{<a name="line.116"></a>
-<span class="sourceLineNo">117</span> if
(path.startsWith(watcher.getZNodePaths().rsZNode)) {<a name="line.117"></a>
-<span class="sourceLineNo">118</span> String serverName =
ZKUtil.getNodeName(path);<a name="line.118"></a>
-<span class="sourceLineNo">119</span> LOG.info("RegionServer ephemeral
node created, adding [" + serverName + "]");<a name="line.119"></a>
-<span class="sourceLineNo">120</span> if (server.isInitialized()) {<a
name="line.120"></a>
-<span class="sourceLineNo">121</span> // Only call the check to move
servers if a RegionServer was added to the cluster; in this<a
name="line.121"></a>
-<span class="sourceLineNo">122</span> // case it could be a server with
a new version so it makes sense to run the check.<a name="line.122"></a>
-<span class="sourceLineNo">123</span>
server.checkIfShouldMoveSystemRegionAsync();<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> }<a name="line.126"></a>
-<span class="sourceLineNo">127</span><a name="line.127"></a>
-<span class="sourceLineNo">128</span> @Override<a name="line.128"></a>
-<span class="sourceLineNo">129</span> public void nodeDeleted(String path)
{<a name="line.129"></a>
-<span class="sourceLineNo">130</span> if
(path.startsWith(watcher.getZNodePaths().rsZNode)) {<a name="line.130"></a>
-<span class="sourceLineNo">131</span> String serverName =
ZKUtil.getNodeName(path);<a name="line.131"></a>
-<span class="sourceLineNo">132</span> LOG.info("RegionServer ephemeral
node deleted, processing expiration [" +<a name="line.132"></a>
-<span class="sourceLineNo">133</span> serverName + "]");<a
name="line.133"></a>
-<span class="sourceLineNo">134</span> ServerName sn =
ServerName.parseServerName(serverName);<a name="line.134"></a>
-<span class="sourceLineNo">135</span> if
(!serverManager.isServerOnline(sn)) {<a name="line.135"></a>
-<span class="sourceLineNo">136</span> LOG.warn(serverName.toString() +
" is not online or isn't known to the master."+<a name="line.136"></a>
-<span class="sourceLineNo">137</span> "The latter could be caused by a
DNS misconfiguration.");<a name="line.137"></a>
-<span class="sourceLineNo">138</span> return;<a name="line.138"></a>
-<span class="sourceLineNo">139</span> }<a name="line.139"></a>
-<span class="sourceLineNo">140</span> remove(sn);<a name="line.140"></a>
-<span class="sourceLineNo">141</span>
this.serverManager.expireServer(sn);<a name="line.141"></a>
-<span class="sourceLineNo">142</span> }<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 nodeChildrenChanged(String
path) {<a name="line.146"></a>
-<span class="sourceLineNo">147</span> if
(path.equals(watcher.getZNodePaths().rsZNode)<a name="line.147"></a>
-<span class="sourceLineNo">148</span> && !server.isAborted()
&& !server.isStopped()) {<a name="line.148"></a>
-<span class="sourceLineNo">149</span> try {<a name="line.149"></a>
-<span class="sourceLineNo">150</span> List<String> servers =<a
name="line.150"></a>
-<span class="sourceLineNo">151</span>
ZKUtil.listChildrenAndWatchThem(watcher, watcher.getZNodePaths().rsZNode);<a
name="line.151"></a>
-<span class="sourceLineNo">152</span> refresh(servers);<a
name="line.152"></a>
-<span class="sourceLineNo">153</span> } catch (IOException e) {<a
name="line.153"></a>
-<span class="sourceLineNo">154</span> server.abort("Unexpected zk
exception getting RS nodes", e);<a name="line.154"></a>
-<span class="sourceLineNo">155</span> } catch (KeeperException e) {<a
name="line.155"></a>
-<span class="sourceLineNo">156</span> server.abort("Unexpected zk
exception getting RS nodes", e);<a name="line.156"></a>
-<span class="sourceLineNo">157</span> }<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><a name="line.160"></a>
-<span class="sourceLineNo">161</span> public RegionServerInfo
getRegionServerInfo(final ServerName sn) {<a name="line.161"></a>
-<span class="sourceLineNo">162</span> return regionServers.get(sn);<a
name="line.162"></a>
-<span class="sourceLineNo">163</span> }<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> * Gets the online servers.<a
name="line.166"></a>
-<span class="sourceLineNo">167</span> * @return list of online servers<a
name="line.167"></a>
-<span class="sourceLineNo">168</span> */<a name="line.168"></a>
-<span class="sourceLineNo">169</span> public List<ServerName>
getOnlineServers() {<a name="line.169"></a>
-<span class="sourceLineNo">170</span> synchronized (this.regionServers) {<a
name="line.170"></a>
-<span class="sourceLineNo">171</span> return new
ArrayList<>(this.regionServers.keySet());<a name="line.171"></a>
-<span class="sourceLineNo">172</span> }<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">025</span>import java.util.Set;<a
name="line.25"></a>
+<span class="sourceLineNo">026</span>import
java.util.concurrent.ExecutorService;<a name="line.26"></a>
+<span class="sourceLineNo">027</span>import java.util.concurrent.Executors;<a
name="line.27"></a>
+<span class="sourceLineNo">028</span>import java.util.stream.Collectors;<a
name="line.28"></a>
+<span class="sourceLineNo">029</span>import
org.apache.hadoop.hbase.ServerMetrics;<a name="line.29"></a>
+<span class="sourceLineNo">030</span>import
org.apache.hadoop.hbase.ServerMetricsBuilder;<a name="line.30"></a>
+<span class="sourceLineNo">031</span>import
org.apache.hadoop.hbase.ServerName;<a name="line.31"></a>
+<span class="sourceLineNo">032</span>import
org.apache.hadoop.hbase.client.VersionInfoUtil;<a name="line.32"></a>
+<span class="sourceLineNo">033</span>import
org.apache.hadoop.hbase.util.Pair;<a name="line.33"></a>
+<span class="sourceLineNo">034</span>import
org.apache.hadoop.hbase.zookeeper.ZKListener;<a name="line.34"></a>
+<span class="sourceLineNo">035</span>import
org.apache.hadoop.hbase.zookeeper.ZKUtil;<a name="line.35"></a>
+<span class="sourceLineNo">036</span>import
org.apache.hadoop.hbase.zookeeper.ZKWatcher;<a name="line.36"></a>
+<span class="sourceLineNo">037</span>import
org.apache.hadoop.hbase.zookeeper.ZNodePaths;<a name="line.37"></a>
+<span class="sourceLineNo">038</span>import
org.apache.yetus.audience.InterfaceAudience;<a name="line.38"></a>
+<span class="sourceLineNo">039</span>import
org.apache.zookeeper.KeeperException;<a name="line.39"></a>
+<span class="sourceLineNo">040</span>import org.slf4j.Logger;<a
name="line.40"></a>
+<span class="sourceLineNo">041</span>import org.slf4j.LoggerFactory;<a
name="line.41"></a>
+<span class="sourceLineNo">042</span><a name="line.42"></a>
+<span class="sourceLineNo">043</span>import
org.apache.hbase.thirdparty.com.google.common.util.concurrent.ThreadFactoryBuilder;<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.ProtobufUtil;<a name="line.45"></a>
+<span class="sourceLineNo">046</span>import
org.apache.hadoop.hbase.shaded.protobuf.generated.HBaseProtos.RegionServerInfo;<a
name="line.46"></a>
+<span class="sourceLineNo">047</span><a name="line.47"></a>
+<span class="sourceLineNo">048</span>/**<a name="line.48"></a>
+<span class="sourceLineNo">049</span> * <p><a name="line.49"></a>
+<span class="sourceLineNo">050</span> * Tracks the online region servers via
ZK.<a name="line.50"></a>
+<span class="sourceLineNo">051</span> * </p><a name="line.51"></a>
+<span class="sourceLineNo">052</span> * <p><a name="line.52"></a>
+<span class="sourceLineNo">053</span> * Handling of new RSs checking in is
done via RPC. This class is only responsible for watching for<a
name="line.53"></a>
+<span class="sourceLineNo">054</span> * expired nodes. It handles listening
for changes in the RS node list. The only exception is when<a
name="line.54"></a>
+<span class="sourceLineNo">055</span> * master restart, we will use the list
fetched from zk to construct the initial set of live region<a
name="line.55"></a>
+<span class="sourceLineNo">056</span> * servers.<a name="line.56"></a>
+<span class="sourceLineNo">057</span> * </p><a name="line.57"></a>
+<span class="sourceLineNo">058</span> * <p><a name="line.58"></a>
+<span class="sourceLineNo">059</span> * If an RS node gets deleted, this
automatically handles calling of<a name="line.59"></a>
+<span class="sourceLineNo">060</span> * {@link
ServerManager#expireServer(ServerName)}<a name="line.60"></a>
+<span class="sourceLineNo">061</span> * </p><a name="line.61"></a>
+<span class="sourceLineNo">062</span> */<a name="line.62"></a>
+<span class="sourceLineNo">063</span>@InterfaceAudience.Private<a
name="line.63"></a>
+<span class="sourceLineNo">064</span>public class RegionServerTracker extends
ZKListener {<a name="line.64"></a>
+<span class="sourceLineNo">065</span> private static final Logger LOG =
LoggerFactory.getLogger(RegionServerTracker.class);<a name="line.65"></a>
+<span class="sourceLineNo">066</span> private final Set<ServerName>
regionServers = new HashSet<>();<a name="line.66"></a>
+<span class="sourceLineNo">067</span> private final ServerManager
serverManager;<a name="line.67"></a>
+<span class="sourceLineNo">068</span> private final MasterServices server;<a
name="line.68"></a>
+<span class="sourceLineNo">069</span> // As we need to send request to zk
when processing the nodeChildrenChanged event, we'd better<a name="line.69"></a>
+<span class="sourceLineNo">070</span> // move the operation to a single
threaded thread pool in order to not block the zk event<a name="line.70"></a>
+<span class="sourceLineNo">071</span> // processing since all the zk listener
across HMaster will be called in one thread sequentially.<a name="line.71"></a>
+<span class="sourceLineNo">072</span> private final ExecutorService
executor;<a name="line.72"></a>
+<span class="sourceLineNo">073</span><a name="line.73"></a>
+<span class="sourceLineNo">074</span> public RegionServerTracker(ZKWatcher
watcher, MasterServices server,<a name="line.74"></a>
+<span class="sourceLineNo">075</span> ServerManager serverManager) {<a
name="line.75"></a>
+<span class="sourceLineNo">076</span> super(watcher);<a name="line.76"></a>
+<span class="sourceLineNo">077</span> this.server = server;<a
name="line.77"></a>
+<span class="sourceLineNo">078</span> this.serverManager = serverManager;<a
name="line.78"></a>
+<span class="sourceLineNo">079</span> executor =
Executors.newSingleThreadExecutor(<a name="line.79"></a>
+<span class="sourceLineNo">080</span> new
ThreadFactoryBuilder().setDaemon(true).setNameFormat("RegionServerTracker-%d").build());<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> private Pair<ServerName,
RegionServerInfo> getServerInfo(String name)<a name="line.83"></a>
+<span class="sourceLineNo">084</span> throws KeeperException, IOException
{<a name="line.84"></a>
+<span class="sourceLineNo">085</span> ServerName serverName =
ServerName.parseServerName(name);<a name="line.85"></a>
+<span class="sourceLineNo">086</span> String nodePath =
ZNodePaths.joinZNode(watcher.getZNodePaths().rsZNode, name);<a
name="line.86"></a>
+<span class="sourceLineNo">087</span> byte[] data;<a name="line.87"></a>
+<span class="sourceLineNo">088</span> try {<a name="line.88"></a>
+<span class="sourceLineNo">089</span> data = ZKUtil.getData(watcher,
nodePath);<a name="line.89"></a>
+<span class="sourceLineNo">090</span> } catch (InterruptedException e) {<a
name="line.90"></a>
+<span class="sourceLineNo">091</span> throw (InterruptedIOException) new
InterruptedIOException().initCause(e);<a name="line.91"></a>
+<span class="sourceLineNo">092</span> }<a name="line.92"></a>
+<span class="sourceLineNo">093</span> if (data == null) {<a
name="line.93"></a>
+<span class="sourceLineNo">094</span> // we should receive a children
changed event later and then we will expire it, so we still<a
name="line.94"></a>
+<span class="sourceLineNo">095</span> // need to add it to the region
server set.<a name="line.95"></a>
+<span class="sourceLineNo">096</span> LOG.warn("Server node {} does not
exist, already dead?", name);<a name="line.96"></a>
+<span class="sourceLineNo">097</span> return Pair.newPair(serverName,
null);<a name="line.97"></a>
+<span class="sourceLineNo">098</span> }<a name="line.98"></a>
+<span class="sourceLineNo">099</span> if (data.length == 0 ||
!ProtobufUtil.isPBMagicPrefix(data)) {<a name="line.99"></a>
+<span class="sourceLineNo">100</span> // this should not happen actually,
unless we have bugs or someone has messed zk up.<a name="line.100"></a>
+<span class="sourceLineNo">101</span> LOG.warn("Invalid data for region
server node {} on zookeeper, data length = {}", name,<a name="line.101"></a>
+<span class="sourceLineNo">102</span> data.length);<a
name="line.102"></a>
+<span class="sourceLineNo">103</span> return Pair.newPair(serverName,
null);<a name="line.103"></a>
+<span class="sourceLineNo">104</span> }<a name="line.104"></a>
+<span class="sourceLineNo">105</span> RegionServerInfo.Builder builder =
RegionServerInfo.newBuilder();<a name="line.105"></a>
+<span class="sourceLineNo">106</span> int magicLen =
ProtobufUtil.lengthOfPBMagic();<a name="line.106"></a>
+<span class="sourceLineNo">107</span> ProtobufUtil.mergeFrom(builder, data,
magicLen, data.length - magicLen);<a name="line.107"></a>
+<span class="sourceLineNo">108</span> return Pair.newPair(serverName,
builder.build());<a name="line.108"></a>
+<span class="sourceLineNo">109</span> }<a name="line.109"></a>
+<span class="sourceLineNo">110</span><a name="line.110"></a>
+<span class="sourceLineNo">111</span> /**<a name="line.111"></a>
+<span class="sourceLineNo">112</span> * <p><a name="line.112"></a>
+<span class="sourceLineNo">113</span> * Starts the tracking of online
RegionServers.<a name="line.113"></a>
+<span class="sourceLineNo">114</span> * </p><a name="line.114"></a>
+<span class="sourceLineNo">115</span> * <p><a name="line.115"></a>
+<span class="sourceLineNo">116</span> * All RSs will be tracked after this
method is called.<a name="line.116"></a>
+<span class="sourceLineNo">117</span> * </p><a name="line.117"></a>
+<span class="sourceLineNo">118</span> */<a name="line.118"></a>
+<span class="sourceLineNo">119</span> public void start() throws
KeeperException, IOException {<a name="line.119"></a>
+<span class="sourceLineNo">120</span> watcher.registerListener(this);<a
name="line.120"></a>
+<span class="sourceLineNo">121</span> synchronized (this) {<a
name="line.121"></a>
+<span class="sourceLineNo">122</span> List<String> servers =<a
name="line.122"></a>
+<span class="sourceLineNo">123</span>
ZKUtil.listChildrenAndWatchForNewChildren(watcher,
watcher.getZNodePaths().rsZNode);<a name="line.123"></a>
+<span class="sourceLineNo">124</span> for (String n : servers) {<a
name="line.124"></a>
+<span class="sourceLineNo">125</span> Pair<ServerName,
RegionServerInfo> pair = getServerInfo(n);<a name="line.125"></a>
+<span class="sourceLineNo">126</span> ServerName serverName =
pair.getFirst();<a name="line.126"></a>
+<span class="sourceLineNo">127</span> RegionServerInfo info =
pair.getSecond();<a name="line.127"></a>
+<span class="sourceLineNo">128</span> regionServers.add(serverName);<a
name="line.128"></a>
+<span class="sourceLineNo">129</span> ServerMetrics serverMetrics =
info != null<a name="line.129"></a>
+<span class="sourceLineNo">130</span> ?
ServerMetricsBuilder.of(serverName,<a name="line.130"></a>
+<span class="sourceLineNo">131</span>
VersionInfoUtil.getVersionNumber(info.getVersionInfo()))<a name="line.131"></a>
+<span class="sourceLineNo">132</span> :
ServerMetricsBuilder.of(serverName);<a name="line.132"></a>
+<span class="sourceLineNo">133</span>
serverManager.checkAndRecordNewServer(serverName, serverMetrics);<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> public void stop() {<a
name="line.138"></a>
+<span class="sourceLineNo">139</span> executor.shutdownNow();<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> private synchronized void refresh() {<a
name="line.142"></a>
+<span class="sourceLineNo">143</span> List<String> names;<a
name="line.143"></a>
+<span class="sourceLineNo">144</span> try {<a name="line.144"></a>
+<span class="sourceLineNo">145</span> names =
ZKUtil.listChildrenAndWatchForNewChildren(watcher,
watcher.getZNodePaths().rsZNode);<a name="line.145"></a>
+<span class="sourceLineNo">146</span> } catch (KeeperException e) {<a
name="line.146"></a>
+<span class="sourceLineNo">147</span> // here we need to abort as we
failed to set watcher on the rs node which means that we can<a
name="line.147"></a>
+<span class="sourceLineNo">148</span> // not track the node deleted
evetnt any more.<a name="line.148"></a>
+<span class="sourceLineNo">149</span> server.abort("Unexpected zk
exception getting RS nodes", e);<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> Set<ServerName> servers =<a
name="line.152"></a>
+<span class="sourceLineNo">153</span>
names.stream().map(ServerName::parseServerName).collect(Collectors.toSet());<a
name="line.153"></a>
+<span class="sourceLineNo">154</span> for (Iterator<ServerName> iter
= regionServers.iterator(); iter.hasNext();) {<a name="line.154"></a>
+<span class="sourceLineNo">155</span> ServerName sn = iter.next();<a
name="line.155"></a>
+<span class="sourceLineNo">156</span> if (!servers.contains(sn)) {<a
name="line.156"></a>
+<span class="sourceLineNo">157</span> LOG.info("RegionServer ephemeral
node deleted, processing expiration [{}]", sn);<a name="line.157"></a>
+<span class="sourceLineNo">158</span> serverManager.expireServer(sn);<a
name="line.158"></a>
+<span class="sourceLineNo">159</span> iter.remove();<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> // here we do not need to parse the
region server info as it is useless now, we only need the<a name="line.162"></a>
+<span class="sourceLineNo">163</span> // server name.<a name="line.163"></a>
+<span class="sourceLineNo">164</span> boolean newServerAdded = false;<a
name="line.164"></a>
+<span class="sourceLineNo">165</span> for (ServerName sn : servers) {<a
name="line.165"></a>
+<span class="sourceLineNo">166</span> if (regionServers.add(sn)) {<a
name="line.166"></a>
+<span class="sourceLineNo">167</span> newServerAdded = true;<a
name="line.167"></a>
+<span class="sourceLineNo">168</span> LOG.info("RegionServer ephemeral
node created, adding [" + sn + "]");<a name="line.168"></a>
+<span class="sourceLineNo">169</span> }<a name="line.169"></a>
+<span class="sourceLineNo">170</span> }<a name="line.170"></a>
+<span class="sourceLineNo">171</span> if (newServerAdded &&
server.isInitialized()) {<a name="line.171"></a>
+<span class="sourceLineNo">172</span> // Only call the check to move
servers if a RegionServer was added to the cluster; in this<a
name="line.172"></a>
+<span class="sourceLineNo">173</span> // case it could be a server with a
new version so it makes sense to run the check.<a name="line.173"></a>
+<span class="sourceLineNo">174</span>
server.checkIfShouldMoveSystemRegionAsync();<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><a name="line.177"></a>
+<span class="sourceLineNo">178</span> @Override<a name="line.178"></a>
+<span class="sourceLineNo">179</span> public void nodeChildrenChanged(String
path) {<a name="line.179"></a>
+<span class="sourceLineNo">180</span> if
(path.equals(watcher.getZNodePaths().rsZNode) && !server.isAborted()
&&<a name="line.180"></a>
+<span class="sourceLineNo">181</span> !server.isStopped()) {<a
name="line.181"></a>
+<span class="sourceLineNo">182</span> executor.execute(this::refresh);<a
name="line.182"></a>
+<span class="sourceLineNo">183</span> }<a name="line.183"></a>
+<span class="sourceLineNo">184</span> }<a name="line.184"></a>
+<span class="sourceLineNo">185</span>}<a name="line.185"></a>
