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| <pre><span class="source-line-no">001</span><span id="line-1">/*</span> |
| <span class="source-line-no">002</span><span id="line-2"> * Licensed to the Apache Software Foundation (ASF) under one</span> |
| <span class="source-line-no">003</span><span id="line-3"> * or more contributor license agreements. See the NOTICE file</span> |
| <span class="source-line-no">004</span><span id="line-4"> * distributed with this work for additional information</span> |
| <span class="source-line-no">005</span><span id="line-5"> * regarding copyright ownership. The ASF licenses this file</span> |
| <span class="source-line-no">006</span><span id="line-6"> * to you under the Apache License, Version 2.0 (the</span> |
| <span class="source-line-no">007</span><span id="line-7"> * "License"); you may not use this file except in compliance</span> |
| <span class="source-line-no">008</span><span id="line-8"> * with the License. You may obtain a copy of the License at</span> |
| <span class="source-line-no">009</span><span id="line-9"> *</span> |
| <span class="source-line-no">010</span><span id="line-10"> * http://www.apache.org/licenses/LICENSE-2.0</span> |
| <span class="source-line-no">011</span><span id="line-11"> *</span> |
| <span class="source-line-no">012</span><span id="line-12"> * Unless required by applicable law or agreed to in writing, software</span> |
| <span class="source-line-no">013</span><span id="line-13"> * distributed under the License is distributed on an "AS IS" BASIS,</span> |
| <span class="source-line-no">014</span><span id="line-14"> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.</span> |
| <span class="source-line-no">015</span><span id="line-15"> * See the License for the specific language governing permissions and</span> |
| <span class="source-line-no">016</span><span id="line-16"> * limitations under the License.</span> |
| <span class="source-line-no">017</span><span id="line-17"> */</span> |
| <span class="source-line-no">018</span><span id="line-18">package org.apache.hadoop.hbase.master;</span> |
| <span class="source-line-no">019</span><span id="line-19"></span> |
| <span class="source-line-no">020</span><span id="line-20">import java.io.IOException;</span> |
| <span class="source-line-no">021</span><span id="line-21">import java.io.InterruptedIOException;</span> |
| <span class="source-line-no">022</span><span id="line-22">import org.apache.hadoop.conf.Configuration;</span> |
| <span class="source-line-no">023</span><span id="line-23">import org.apache.hadoop.hbase.Server;</span> |
| <span class="source-line-no">024</span><span id="line-24">import org.apache.hadoop.hbase.ServerName;</span> |
| <span class="source-line-no">025</span><span id="line-25">import org.apache.hadoop.hbase.monitoring.MonitoredTask;</span> |
| <span class="source-line-no">026</span><span id="line-26">import org.apache.hadoop.hbase.monitoring.TaskGroup;</span> |
| <span class="source-line-no">027</span><span id="line-27">import org.apache.hadoop.hbase.util.Threads;</span> |
| <span class="source-line-no">028</span><span id="line-28">import org.apache.hadoop.hbase.zookeeper.MasterAddressTracker;</span> |
| <span class="source-line-no">029</span><span id="line-29">import org.apache.hadoop.hbase.zookeeper.ZKWatcher;</span> |
| <span class="source-line-no">030</span><span id="line-30">import org.apache.zookeeper.KeeperException;</span> |
| <span class="source-line-no">031</span><span id="line-31">import org.slf4j.Logger;</span> |
| <span class="source-line-no">032</span><span id="line-32">import org.slf4j.LoggerFactory;</span> |
| <span class="source-line-no">033</span><span id="line-33"></span> |
| <span class="source-line-no">034</span><span id="line-34">/**</span> |
| <span class="source-line-no">035</span><span id="line-35"> * An implementation of HMaster that always runs as a stand by and never transitions to active.</span> |
| <span class="source-line-no">036</span><span id="line-36"> */</span> |
| <span class="source-line-no">037</span><span id="line-37">public class AlwaysStandByHMaster extends HMaster {</span> |
| <span class="source-line-no">038</span><span id="line-38"> /**</span> |
| <span class="source-line-no">039</span><span id="line-39"> * An implementation of ActiveMasterManager that never transitions it's master to active state. It</span> |
| <span class="source-line-no">040</span><span id="line-40"> * always remains as a stand by master. With the master registry implementation (HBASE-18095) it</span> |
| <span class="source-line-no">041</span><span id="line-41"> * is expected to have at least one active / standby master always running at any point in time</span> |
| <span class="source-line-no">042</span><span id="line-42"> * since they serve as the gateway for client connections. With this implementation, tests can</span> |
| <span class="source-line-no">043</span><span id="line-43"> * simulate the scenario of not having an active master yet the client connections to the cluster</span> |
| <span class="source-line-no">044</span><span id="line-44"> * succeed.</span> |
| <span class="source-line-no">045</span><span id="line-45"> */</span> |
| <span class="source-line-no">046</span><span id="line-46"> private static class AlwaysStandByMasterManager extends ActiveMasterManager {</span> |
| <span class="source-line-no">047</span><span id="line-47"> private static final Logger LOG = LoggerFactory.getLogger(AlwaysStandByMasterManager.class);</span> |
| <span class="source-line-no">048</span><span id="line-48"></span> |
| <span class="source-line-no">049</span><span id="line-49"> AlwaysStandByMasterManager(ZKWatcher watcher, ServerName sn, Server master)</span> |
| <span class="source-line-no">050</span><span id="line-50"> throws InterruptedIOException {</span> |
| <span class="source-line-no">051</span><span id="line-51"> super(watcher, sn, master);</span> |
| <span class="source-line-no">052</span><span id="line-52"> }</span> |
| <span class="source-line-no">053</span><span id="line-53"></span> |
| <span class="source-line-no">054</span><span id="line-54"> /**</span> |
| <span class="source-line-no">055</span><span id="line-55"> * An implementation that never transitions to an active master.</span> |
| <span class="source-line-no">056</span><span id="line-56"> */</span> |
| <span class="source-line-no">057</span><span id="line-57"> @Override</span> |
| <span class="source-line-no">058</span><span id="line-58"> boolean blockUntilBecomingActiveMaster(int checkInterval, TaskGroup startupTaskGroup) {</span> |
| <span class="source-line-no">059</span><span id="line-59"> MonitoredTask loopTask = startupTaskGroup.addTask("Stay as a standby master.");</span> |
| <span class="source-line-no">060</span><span id="line-60"> while (!(master.isAborted() || master.isStopped())) {</span> |
| <span class="source-line-no">061</span><span id="line-61"> loopTask.setStatus("Forever looping to stay as a standby master.");</span> |
| <span class="source-line-no">062</span><span id="line-62"> try {</span> |
| <span class="source-line-no">063</span><span id="line-63"> activeMasterServerName = null;</span> |
| <span class="source-line-no">064</span><span id="line-64"> try {</span> |
| <span class="source-line-no">065</span><span id="line-65"> if (MasterAddressTracker.getMasterAddress(watcher) != null) {</span> |
| <span class="source-line-no">066</span><span id="line-66"> clusterHasActiveMaster.set(true);</span> |
| <span class="source-line-no">067</span><span id="line-67"> }</span> |
| <span class="source-line-no">068</span><span id="line-68"> } catch (IOException e) {</span> |
| <span class="source-line-no">069</span><span id="line-69"> // pass, we will get notified when some other active master creates the znode.</span> |
| <span class="source-line-no">070</span><span id="line-70"> }</span> |
| <span class="source-line-no">071</span><span id="line-71"> Threads.sleepWithoutInterrupt(1000);</span> |
| <span class="source-line-no">072</span><span id="line-72"> } catch (KeeperException e) {</span> |
| <span class="source-line-no">073</span><span id="line-73"> master.abort("Received an unexpected KeeperException, aborting", e);</span> |
| <span class="source-line-no">074</span><span id="line-74"> return false;</span> |
| <span class="source-line-no">075</span><span id="line-75"> }</span> |
| <span class="source-line-no">076</span><span id="line-76"> synchronized (this.clusterHasActiveMaster) {</span> |
| <span class="source-line-no">077</span><span id="line-77"> while (clusterHasActiveMaster.get() && !master.isStopped()) {</span> |
| <span class="source-line-no">078</span><span id="line-78"> try {</span> |
| <span class="source-line-no">079</span><span id="line-79"> clusterHasActiveMaster.wait(checkInterval);</span> |
| <span class="source-line-no">080</span><span id="line-80"> } catch (InterruptedException e) {</span> |
| <span class="source-line-no">081</span><span id="line-81"> // We expect to be interrupted when a master dies,</span> |
| <span class="source-line-no">082</span><span id="line-82"> // will fall out if so</span> |
| <span class="source-line-no">083</span><span id="line-83"> LOG.debug("Interrupted waiting for master to die", e);</span> |
| <span class="source-line-no">084</span><span id="line-84"> }</span> |
| <span class="source-line-no">085</span><span id="line-85"> }</span> |
| <span class="source-line-no">086</span><span id="line-86"> if (clusterShutDown.get()) {</span> |
| <span class="source-line-no">087</span><span id="line-87"> this.master.stop("Cluster went down before this master became active");</span> |
| <span class="source-line-no">088</span><span id="line-88"> }</span> |
| <span class="source-line-no">089</span><span id="line-89"> }</span> |
| <span class="source-line-no">090</span><span id="line-90"> }</span> |
| <span class="source-line-no">091</span><span id="line-91"> return false;</span> |
| <span class="source-line-no">092</span><span id="line-92"> }</span> |
| <span class="source-line-no">093</span><span id="line-93"> }</span> |
| <span class="source-line-no">094</span><span id="line-94"></span> |
| <span class="source-line-no">095</span><span id="line-95"> public AlwaysStandByHMaster(Configuration conf) throws IOException {</span> |
| <span class="source-line-no">096</span><span id="line-96"> super(conf);</span> |
| <span class="source-line-no">097</span><span id="line-97"> }</span> |
| <span class="source-line-no">098</span><span id="line-98"></span> |
| <span class="source-line-no">099</span><span id="line-99"> protected ActiveMasterManager createActiveMasterManager(ZKWatcher zk, ServerName sn,</span> |
| <span class="source-line-no">100</span><span id="line-100"> org.apache.hadoop.hbase.Server server) throws InterruptedIOException {</span> |
| <span class="source-line-no">101</span><span id="line-101"> return new AlwaysStandByMasterManager(zk, sn, server);</span> |
| <span class="source-line-no">102</span><span id="line-102"> }</span> |
| <span class="source-line-no">103</span><span id="line-103">}</span> |
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| </pre> |
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