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<pre><span class="sourceLineNo">001</span>/*<a name="line.1"></a>
<span class="sourceLineNo">002</span> * Licensed to the Apache Software Foundation (ASF) under one<a name="line.2"></a>
<span class="sourceLineNo">003</span> * or more contributor license agreements. See the NOTICE file<a name="line.3"></a>
<span class="sourceLineNo">004</span> * distributed with this work for additional information<a name="line.4"></a>
<span class="sourceLineNo">005</span> * regarding copyright ownership. The ASF licenses this file<a name="line.5"></a>
<span class="sourceLineNo">006</span> * to you under the Apache License, Version 2.0 (the<a name="line.6"></a>
<span class="sourceLineNo">007</span> * "License"); you may not use this file except in compliance<a name="line.7"></a>
<span class="sourceLineNo">008</span> * with the License. You may obtain a copy of the License at<a name="line.8"></a>
<span class="sourceLineNo">009</span> *<a name="line.9"></a>
<span class="sourceLineNo">010</span> * http://www.apache.org/licenses/LICENSE-2.0<a name="line.10"></a>
<span class="sourceLineNo">011</span> *<a name="line.11"></a>
<span class="sourceLineNo">012</span> * Unless required by applicable law or agreed to in writing, software<a name="line.12"></a>
<span class="sourceLineNo">013</span> * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.13"></a>
<span class="sourceLineNo">014</span> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.14"></a>
<span class="sourceLineNo">015</span> * See the License for the specific language governing permissions and<a name="line.15"></a>
<span class="sourceLineNo">016</span> * limitations under the License.<a name="line.16"></a>
<span class="sourceLineNo">017</span> */<a name="line.17"></a>
<span class="sourceLineNo">018</span>package org.apache.hadoop.hbase.procedure;<a name="line.18"></a>
<span class="sourceLineNo">019</span><a name="line.19"></a>
<span class="sourceLineNo">020</span>import java.io.Closeable;<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 org.apache.hadoop.hbase.zookeeper.ZKListener;<a name="line.23"></a>
<span class="sourceLineNo">024</span>import org.apache.hadoop.hbase.zookeeper.ZKUtil;<a name="line.24"></a>
<span class="sourceLineNo">025</span>import org.apache.hadoop.hbase.zookeeper.ZKWatcher;<a name="line.25"></a>
<span class="sourceLineNo">026</span>import org.apache.hadoop.hbase.zookeeper.ZNodePaths;<a name="line.26"></a>
<span class="sourceLineNo">027</span>import org.apache.yetus.audience.InterfaceAudience;<a name="line.27"></a>
<span class="sourceLineNo">028</span>import org.apache.zookeeper.KeeperException;<a name="line.28"></a>
<span class="sourceLineNo">029</span>import org.slf4j.Logger;<a name="line.29"></a>
<span class="sourceLineNo">030</span>import org.slf4j.LoggerFactory;<a name="line.30"></a>
<span class="sourceLineNo">031</span><a name="line.31"></a>
<span class="sourceLineNo">032</span>/**<a name="line.32"></a>
<span class="sourceLineNo">033</span> * This is a shared ZooKeeper-based znode management utils for distributed procedure. All znode<a name="line.33"></a>
<span class="sourceLineNo">034</span> * operations should go through the provided methods in coordinators and members. Layout of nodes in<a name="line.34"></a>
<span class="sourceLineNo">035</span> * ZK is /hbase/[op name]/acquired/ [op instance] - op data/ /[nodes that have acquired] /reached/<a name="line.35"></a>
<span class="sourceLineNo">036</span> * [op instance]/ /[nodes that have completed] /abort/ [op instance] - failure data NOTE: while<a name="line.36"></a>
<span class="sourceLineNo">037</span> * acquired and completed are znode dirs, abort is actually just a znode. Assumption here that<a name="line.37"></a>
<span class="sourceLineNo">038</span> * procedure names are unique<a name="line.38"></a>
<span class="sourceLineNo">039</span> */<a name="line.39"></a>
<span class="sourceLineNo">040</span>@InterfaceAudience.Private<a name="line.40"></a>
<span class="sourceLineNo">041</span>public abstract class ZKProcedureUtil extends ZKListener implements Closeable {<a name="line.41"></a>
<span class="sourceLineNo">042</span><a name="line.42"></a>
<span class="sourceLineNo">043</span> private static final Logger LOG = LoggerFactory.getLogger(ZKProcedureUtil.class);<a name="line.43"></a>
<span class="sourceLineNo">044</span><a name="line.44"></a>
<span class="sourceLineNo">045</span> public static final String ACQUIRED_BARRIER_ZNODE_DEFAULT = "acquired";<a name="line.45"></a>
<span class="sourceLineNo">046</span> public static final String REACHED_BARRIER_ZNODE_DEFAULT = "reached";<a name="line.46"></a>
<span class="sourceLineNo">047</span> public static final String ABORT_ZNODE_DEFAULT = "abort";<a name="line.47"></a>
<span class="sourceLineNo">048</span><a name="line.48"></a>
<span class="sourceLineNo">049</span> public final String baseZNode;<a name="line.49"></a>
<span class="sourceLineNo">050</span> protected final String acquiredZnode;<a name="line.50"></a>
<span class="sourceLineNo">051</span> protected final String reachedZnode;<a name="line.51"></a>
<span class="sourceLineNo">052</span> protected final String abortZnode;<a name="line.52"></a>
<span class="sourceLineNo">053</span><a name="line.53"></a>
<span class="sourceLineNo">054</span> /**<a name="line.54"></a>
<span class="sourceLineNo">055</span> * Top-level watcher/controller for procedures across the cluster.<a name="line.55"></a>
<span class="sourceLineNo">056</span> * &lt;p&gt;<a name="line.56"></a>
<span class="sourceLineNo">057</span> * On instantiation, this ensures the procedure znodes exist. This however requires the passed in<a name="line.57"></a>
<span class="sourceLineNo">058</span> * watcher has been started.<a name="line.58"></a>
<span class="sourceLineNo">059</span> * @param watcher watcher for the cluster ZK. Owned by &lt;tt&gt;this&lt;/tt&gt; and closed via<a name="line.59"></a>
<span class="sourceLineNo">060</span> * {@link #close()}<a name="line.60"></a>
<span class="sourceLineNo">061</span> * @param procDescription name of the znode describing the procedure to run<a name="line.61"></a>
<span class="sourceLineNo">062</span> * @throws KeeperException when the procedure znodes cannot be created<a name="line.62"></a>
<span class="sourceLineNo">063</span> */<a name="line.63"></a>
<span class="sourceLineNo">064</span> public ZKProcedureUtil(ZKWatcher watcher, String procDescription) throws KeeperException {<a name="line.64"></a>
<span class="sourceLineNo">065</span> super(watcher);<a name="line.65"></a>
<span class="sourceLineNo">066</span> // make sure we are listening for events<a name="line.66"></a>
<span class="sourceLineNo">067</span> watcher.registerListener(this);<a name="line.67"></a>
<span class="sourceLineNo">068</span> // setup paths for the zknodes used in procedures<a name="line.68"></a>
<span class="sourceLineNo">069</span> this.baseZNode = ZNodePaths.joinZNode(watcher.getZNodePaths().baseZNode, procDescription);<a name="line.69"></a>
<span class="sourceLineNo">070</span> acquiredZnode = ZNodePaths.joinZNode(baseZNode, ACQUIRED_BARRIER_ZNODE_DEFAULT);<a name="line.70"></a>
<span class="sourceLineNo">071</span> reachedZnode = ZNodePaths.joinZNode(baseZNode, REACHED_BARRIER_ZNODE_DEFAULT);<a name="line.71"></a>
<span class="sourceLineNo">072</span> abortZnode = ZNodePaths.joinZNode(baseZNode, ABORT_ZNODE_DEFAULT);<a name="line.72"></a>
<span class="sourceLineNo">073</span><a name="line.73"></a>
<span class="sourceLineNo">074</span> // first make sure all the ZK nodes exist<a name="line.74"></a>
<span class="sourceLineNo">075</span> // make sure all the parents exist (sometimes not the case in tests)<a name="line.75"></a>
<span class="sourceLineNo">076</span> ZKUtil.createWithParents(watcher, acquiredZnode);<a name="line.76"></a>
<span class="sourceLineNo">077</span> // regular create because all the parents exist<a name="line.77"></a>
<span class="sourceLineNo">078</span> ZKUtil.createAndFailSilent(watcher, reachedZnode);<a name="line.78"></a>
<span class="sourceLineNo">079</span> ZKUtil.createAndFailSilent(watcher, abortZnode);<a name="line.79"></a>
<span class="sourceLineNo">080</span> }<a name="line.80"></a>
<span class="sourceLineNo">081</span><a name="line.81"></a>
<span class="sourceLineNo">082</span> @Override<a name="line.82"></a>
<span class="sourceLineNo">083</span> public void close() throws IOException {<a name="line.83"></a>
<span class="sourceLineNo">084</span> // the watcher is passed from either Master or Region Server<a name="line.84"></a>
<span class="sourceLineNo">085</span> // watcher.close() will be called by the owner so no need to call close() here<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> public String getAcquiredBarrierNode(String opInstanceName) {<a name="line.88"></a>
<span class="sourceLineNo">089</span> return ZKProcedureUtil.getAcquireBarrierNode(this, opInstanceName);<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> public String getReachedBarrierNode(String opInstanceName) {<a name="line.92"></a>
<span class="sourceLineNo">093</span> return ZKProcedureUtil.getReachedBarrierNode(this, opInstanceName);<a name="line.93"></a>
<span class="sourceLineNo">094</span> }<a name="line.94"></a>
<span class="sourceLineNo">095</span><a name="line.95"></a>
<span class="sourceLineNo">096</span> public String getAbortZNode(String opInstanceName) {<a name="line.96"></a>
<span class="sourceLineNo">097</span> return ZKProcedureUtil.getAbortNode(this, opInstanceName);<a name="line.97"></a>
<span class="sourceLineNo">098</span> }<a name="line.98"></a>
<span class="sourceLineNo">099</span><a name="line.99"></a>
<span class="sourceLineNo">100</span> public String getAbortZnode() {<a name="line.100"></a>
<span class="sourceLineNo">101</span> return abortZnode;<a name="line.101"></a>
<span class="sourceLineNo">102</span> }<a name="line.102"></a>
<span class="sourceLineNo">103</span><a name="line.103"></a>
<span class="sourceLineNo">104</span> public String getBaseZnode() {<a name="line.104"></a>
<span class="sourceLineNo">105</span> return baseZNode;<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> public String getAcquiredBarrier() {<a name="line.108"></a>
<span class="sourceLineNo">109</span> return acquiredZnode;<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> /**<a name="line.112"></a>
<span class="sourceLineNo">113</span> * Get the full znode path for the node used by the coordinator to trigger a global barrier<a name="line.113"></a>
<span class="sourceLineNo">114</span> * acquire on each subprocedure.<a name="line.114"></a>
<span class="sourceLineNo">115</span> * @param controller controller running the procedure<a name="line.115"></a>
<span class="sourceLineNo">116</span> * @param opInstanceName name of the running procedure instance (not the procedure description).<a name="line.116"></a>
<span class="sourceLineNo">117</span> * @return full znode path to the prepare barrier/start node<a name="line.117"></a>
<span class="sourceLineNo">118</span> */<a name="line.118"></a>
<span class="sourceLineNo">119</span> public static String getAcquireBarrierNode(ZKProcedureUtil controller, String opInstanceName) {<a name="line.119"></a>
<span class="sourceLineNo">120</span> return ZNodePaths.joinZNode(controller.acquiredZnode, opInstanceName);<a name="line.120"></a>
<span class="sourceLineNo">121</span> }<a name="line.121"></a>
<span class="sourceLineNo">122</span><a name="line.122"></a>
<span class="sourceLineNo">123</span> /**<a name="line.123"></a>
<span class="sourceLineNo">124</span> * Get the full znode path for the node used by the coordinator to trigger a global barrier<a name="line.124"></a>
<span class="sourceLineNo">125</span> * execution and release on each subprocedure.<a name="line.125"></a>
<span class="sourceLineNo">126</span> * @param controller controller running the procedure<a name="line.126"></a>
<span class="sourceLineNo">127</span> * @param opInstanceName name of the running procedure instance (not the procedure description).<a name="line.127"></a>
<span class="sourceLineNo">128</span> * @return full znode path to the commit barrier<a name="line.128"></a>
<span class="sourceLineNo">129</span> */<a name="line.129"></a>
<span class="sourceLineNo">130</span> public static String getReachedBarrierNode(ZKProcedureUtil controller, String opInstanceName) {<a name="line.130"></a>
<span class="sourceLineNo">131</span> return ZNodePaths.joinZNode(controller.reachedZnode, opInstanceName);<a name="line.131"></a>
<span class="sourceLineNo">132</span> }<a name="line.132"></a>
<span class="sourceLineNo">133</span><a name="line.133"></a>
<span class="sourceLineNo">134</span> /**<a name="line.134"></a>
<span class="sourceLineNo">135</span> * Get the full znode path for the node used by the coordinator or member to trigger an abort of<a name="line.135"></a>
<span class="sourceLineNo">136</span> * the global barrier acquisition or execution in subprocedures.<a name="line.136"></a>
<span class="sourceLineNo">137</span> * @param controller controller running the procedure<a name="line.137"></a>
<span class="sourceLineNo">138</span> * @param opInstanceName name of the running procedure instance (not the procedure description).<a name="line.138"></a>
<span class="sourceLineNo">139</span> * @return full znode path to the abort znode<a name="line.139"></a>
<span class="sourceLineNo">140</span> */<a name="line.140"></a>
<span class="sourceLineNo">141</span> public static String getAbortNode(ZKProcedureUtil controller, String opInstanceName) {<a name="line.141"></a>
<span class="sourceLineNo">142</span> return ZNodePaths.joinZNode(controller.abortZnode, opInstanceName);<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 ZKWatcher getWatcher() {<a name="line.146"></a>
<span class="sourceLineNo">147</span> return watcher;<a name="line.147"></a>
<span class="sourceLineNo">148</span> }<a name="line.148"></a>
<span class="sourceLineNo">149</span><a name="line.149"></a>
<span class="sourceLineNo">150</span> /**<a name="line.150"></a>
<span class="sourceLineNo">151</span> * Is this a procedure related znode path? TODO: this is not strict, can return true if had name<a name="line.151"></a>
<span class="sourceLineNo">152</span> * just starts with same prefix but is different zdir.<a name="line.152"></a>
<span class="sourceLineNo">153</span> * @return true if starts with baseZnode<a name="line.153"></a>
<span class="sourceLineNo">154</span> */<a name="line.154"></a>
<span class="sourceLineNo">155</span> boolean isInProcedurePath(String path) {<a name="line.155"></a>
<span class="sourceLineNo">156</span> return path.startsWith(baseZNode);<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> * Is this the exact procedure barrier acquired znode<a name="line.160"></a>
<span class="sourceLineNo">161</span> */<a name="line.161"></a>
<span class="sourceLineNo">162</span> boolean isAcquiredNode(String path) {<a name="line.162"></a>
<span class="sourceLineNo">163</span> return path.equals(acquiredZnode);<a name="line.163"></a>
<span class="sourceLineNo">164</span> }<a name="line.164"></a>
<span class="sourceLineNo">165</span><a name="line.165"></a>
<span class="sourceLineNo">166</span> /**<a name="line.166"></a>
<span class="sourceLineNo">167</span> * Is this in the procedure barrier acquired znode path<a name="line.167"></a>
<span class="sourceLineNo">168</span> */<a name="line.168"></a>
<span class="sourceLineNo">169</span> boolean isAcquiredPathNode(String path) {<a name="line.169"></a>
<span class="sourceLineNo">170</span> return path.startsWith(this.acquiredZnode) &amp;&amp; !path.equals(acquiredZnode)<a name="line.170"></a>
<span class="sourceLineNo">171</span> &amp;&amp; isMemberNode(path, acquiredZnode);<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">175</span> * Is this the exact procedure barrier reached znode<a name="line.175"></a>
<span class="sourceLineNo">176</span> */<a name="line.176"></a>
<span class="sourceLineNo">177</span> boolean isReachedNode(String path) {<a name="line.177"></a>
<span class="sourceLineNo">178</span> return path.equals(reachedZnode);<a name="line.178"></a>
<span class="sourceLineNo">179</span> }<a name="line.179"></a>
<span class="sourceLineNo">180</span><a name="line.180"></a>
<span class="sourceLineNo">181</span> /**<a name="line.181"></a>
<span class="sourceLineNo">182</span> * Is this in the procedure barrier reached znode path<a name="line.182"></a>
<span class="sourceLineNo">183</span> */<a name="line.183"></a>
<span class="sourceLineNo">184</span> boolean isReachedPathNode(String path) {<a name="line.184"></a>
<span class="sourceLineNo">185</span> return path.startsWith(this.reachedZnode) &amp;&amp; !path.equals(reachedZnode)<a name="line.185"></a>
<span class="sourceLineNo">186</span> &amp;&amp; isMemberNode(path, reachedZnode);<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> /*<a name="line.189"></a>
<span class="sourceLineNo">190</span> * Returns true if the specified path is a member of the "statePath"<a name="line.190"></a>
<span class="sourceLineNo">191</span> * /hbase/&lt;ProcName&gt;/&lt;state&gt;/&lt;instance&gt;/member |------ state path -----| |------------------ path<a name="line.191"></a>
<span class="sourceLineNo">192</span> * ------------------|<a name="line.192"></a>
<span class="sourceLineNo">193</span> */<a name="line.193"></a>
<span class="sourceLineNo">194</span> private boolean isMemberNode(final String path, final String statePath) {<a name="line.194"></a>
<span class="sourceLineNo">195</span> int count = 0;<a name="line.195"></a>
<span class="sourceLineNo">196</span> for (int i = statePath.length(); i &lt; path.length(); ++i) {<a name="line.196"></a>
<span class="sourceLineNo">197</span> count += (path.charAt(i) == ZNodePaths.ZNODE_PATH_SEPARATOR) ? 1 : 0;<a name="line.197"></a>
<span class="sourceLineNo">198</span> }<a name="line.198"></a>
<span class="sourceLineNo">199</span> return count == 2;<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> /**<a name="line.202"></a>
<span class="sourceLineNo">203</span> * Is this in the procedure barrier abort znode path<a name="line.203"></a>
<span class="sourceLineNo">204</span> */<a name="line.204"></a>
<span class="sourceLineNo">205</span> boolean isAbortNode(String path) {<a name="line.205"></a>
<span class="sourceLineNo">206</span> return path.equals(abortZnode);<a name="line.206"></a>
<span class="sourceLineNo">207</span> }<a name="line.207"></a>
<span class="sourceLineNo">208</span><a name="line.208"></a>
<span class="sourceLineNo">209</span> /**<a name="line.209"></a>
<span class="sourceLineNo">210</span> * Is this in the procedure barrier abort znode path<a name="line.210"></a>
<span class="sourceLineNo">211</span> */<a name="line.211"></a>
<span class="sourceLineNo">212</span> public boolean isAbortPathNode(String path) {<a name="line.212"></a>
<span class="sourceLineNo">213</span> return path.startsWith(this.abortZnode) &amp;&amp; !path.equals(abortZnode);<a name="line.213"></a>
<span class="sourceLineNo">214</span> }<a name="line.214"></a>
<span class="sourceLineNo">215</span><a name="line.215"></a>
<span class="sourceLineNo">216</span> // --------------------------------------------------------------------------<a name="line.216"></a>
<span class="sourceLineNo">217</span> // internal debugging methods<a name="line.217"></a>
<span class="sourceLineNo">218</span> // --------------------------------------------------------------------------<a name="line.218"></a>
<span class="sourceLineNo">219</span> /**<a name="line.219"></a>
<span class="sourceLineNo">220</span> * Recursively print the current state of ZK (non-transactional)<a name="line.220"></a>
<span class="sourceLineNo">221</span> * @param root name of the root directory in zk to print<a name="line.221"></a>
<span class="sourceLineNo">222</span> */<a name="line.222"></a>
<span class="sourceLineNo">223</span> void logZKTree(String root) {<a name="line.223"></a>
<span class="sourceLineNo">224</span> if (!LOG.isDebugEnabled()) return;<a name="line.224"></a>
<span class="sourceLineNo">225</span> LOG.debug("Current zk system:");<a name="line.225"></a>
<span class="sourceLineNo">226</span> String prefix = "|-";<a name="line.226"></a>
<span class="sourceLineNo">227</span> LOG.debug(prefix + root);<a name="line.227"></a>
<span class="sourceLineNo">228</span> try {<a name="line.228"></a>
<span class="sourceLineNo">229</span> logZKTree(root, prefix);<a name="line.229"></a>
<span class="sourceLineNo">230</span> } catch (KeeperException e) {<a name="line.230"></a>
<span class="sourceLineNo">231</span> throw new RuntimeException(e);<a name="line.231"></a>
<span class="sourceLineNo">232</span> }<a name="line.232"></a>
<span class="sourceLineNo">233</span> }<a name="line.233"></a>
<span class="sourceLineNo">234</span><a name="line.234"></a>
<span class="sourceLineNo">235</span> /**<a name="line.235"></a>
<span class="sourceLineNo">236</span> * Helper method to print the current state of the ZK tree.<a name="line.236"></a>
<span class="sourceLineNo">237</span> * @see #logZKTree(String)<a name="line.237"></a>
<span class="sourceLineNo">238</span> * @throws KeeperException if an unexpected exception occurs<a name="line.238"></a>
<span class="sourceLineNo">239</span> */<a name="line.239"></a>
<span class="sourceLineNo">240</span> protected void logZKTree(String root, String prefix) throws KeeperException {<a name="line.240"></a>
<span class="sourceLineNo">241</span> List&lt;String&gt; children = ZKUtil.listChildrenNoWatch(watcher, root);<a name="line.241"></a>
<span class="sourceLineNo">242</span> if (children == null) return;<a name="line.242"></a>
<span class="sourceLineNo">243</span> for (String child : children) {<a name="line.243"></a>
<span class="sourceLineNo">244</span> LOG.debug(prefix + child);<a name="line.244"></a>
<span class="sourceLineNo">245</span> String node = ZNodePaths.joinZNode(root.equals("/") ? "" : root, child);<a name="line.245"></a>
<span class="sourceLineNo">246</span> logZKTree(node, prefix + "---");<a name="line.246"></a>
<span class="sourceLineNo">247</span> }<a name="line.247"></a>
<span class="sourceLineNo">248</span> }<a name="line.248"></a>
<span class="sourceLineNo">249</span><a name="line.249"></a>
<span class="sourceLineNo">250</span> public void clearChildZNodes() throws KeeperException {<a name="line.250"></a>
<span class="sourceLineNo">251</span> LOG.debug("Clearing all znodes {}, {}, {}", acquiredZnode, reachedZnode, abortZnode);<a name="line.251"></a>
<span class="sourceLineNo">252</span><a name="line.252"></a>
<span class="sourceLineNo">253</span> // If the coordinator was shutdown mid-procedure, then we are going to lose<a name="line.253"></a>
<span class="sourceLineNo">254</span> // an procedure that was previously started by cleaning out all the previous state. Its much<a name="line.254"></a>
<span class="sourceLineNo">255</span> // harder to figure out how to keep an procedure going and the subject of HBASE-5487.<a name="line.255"></a>
<span class="sourceLineNo">256</span> ZKUtil.deleteChildrenRecursivelyMultiOrSequential(watcher, true, acquiredZnode, reachedZnode,<a name="line.256"></a>
<span class="sourceLineNo">257</span> abortZnode);<a name="line.257"></a>
<span class="sourceLineNo">258</span><a name="line.258"></a>
<span class="sourceLineNo">259</span> if (LOG.isTraceEnabled()) {<a name="line.259"></a>
<span class="sourceLineNo">260</span> logZKTree(this.baseZNode);<a name="line.260"></a>
<span class="sourceLineNo">261</span> }<a name="line.261"></a>
<span class="sourceLineNo">262</span> }<a name="line.262"></a>
<span class="sourceLineNo">263</span><a name="line.263"></a>
<span class="sourceLineNo">264</span> public void clearZNodes(String procedureName) throws KeeperException {<a name="line.264"></a>
<span class="sourceLineNo">265</span> LOG.info("Clearing all znodes for procedure " + procedureName + " including nodes "<a name="line.265"></a>
<span class="sourceLineNo">266</span> + acquiredZnode + " " + reachedZnode + " " + abortZnode);<a name="line.266"></a>
<span class="sourceLineNo">267</span><a name="line.267"></a>
<span class="sourceLineNo">268</span> // Make sure we trigger the watches on these nodes by creating them. (HBASE-13885)<a name="line.268"></a>
<span class="sourceLineNo">269</span> String acquiredBarrierNode = getAcquiredBarrierNode(procedureName);<a name="line.269"></a>
<span class="sourceLineNo">270</span> String reachedBarrierNode = getReachedBarrierNode(procedureName);<a name="line.270"></a>
<span class="sourceLineNo">271</span> String abortZNode = getAbortZNode(procedureName);<a name="line.271"></a>
<span class="sourceLineNo">272</span><a name="line.272"></a>
<span class="sourceLineNo">273</span> ZKUtil.createAndFailSilent(watcher, acquiredBarrierNode);<a name="line.273"></a>
<span class="sourceLineNo">274</span> ZKUtil.createAndFailSilent(watcher, abortZNode);<a name="line.274"></a>
<span class="sourceLineNo">275</span><a name="line.275"></a>
<span class="sourceLineNo">276</span> ZKUtil.deleteNodeRecursivelyMultiOrSequential(watcher, true, acquiredBarrierNode,<a name="line.276"></a>
<span class="sourceLineNo">277</span> reachedBarrierNode, abortZNode);<a name="line.277"></a>
<span class="sourceLineNo">278</span><a name="line.278"></a>
<span class="sourceLineNo">279</span> if (LOG.isTraceEnabled()) {<a name="line.279"></a>
<span class="sourceLineNo">280</span> logZKTree(this.baseZNode);<a name="line.280"></a>
<span class="sourceLineNo">281</span> }<a name="line.281"></a>
<span class="sourceLineNo">282</span> }<a name="line.282"></a>
<span class="sourceLineNo">283</span>}<a name="line.283"></a>
</pre>
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