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1   /*
2    * Copyright 2009 The Apache Software Foundation
3    *
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *     http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing, software
15   * distributed under the License is distributed on an "AS IS" BASIS,
16   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17   * See the License for the specific language governing permissions and
18   * limitations under the License.
19   */
20  package org.apache.hadoop.hbase.zookeeper;
21  
22  import java.io.BufferedReader;
23  import java.io.File;
24  import java.io.IOException;
25  import java.io.InputStreamReader;
26  import java.io.OutputStream;
27  import java.io.Reader;
28  import java.net.BindException;
29  import java.net.InetSocketAddress;
30  import java.net.Socket;
31  import java.util.ArrayList;
32  import java.util.List;
33  import java.util.Random;
34  
35  import org.apache.commons.logging.Log;
36  import org.apache.commons.logging.LogFactory;
37  import org.apache.hadoop.conf.Configuration;
38  import org.apache.hadoop.fs.FileUtil;
39  import org.apache.hadoop.hbase.HConstants;
40  import org.apache.zookeeper.server.NIOServerCnxnFactory;
41  import org.apache.zookeeper.server.ZooKeeperServer;
42  import org.apache.zookeeper.server.persistence.FileTxnLog;
43  
44  /**
45   * TODO: Most of the code in this class is ripped from ZooKeeper tests. Instead
46   * of redoing it, we should contribute updates to their code which let us more
47   * easily access testing helper objects.
48   */
49  public class MiniZooKeeperCluster {
50    private static final Log LOG = LogFactory.getLog(MiniZooKeeperCluster.class);
51  
52    private static final int TICK_TIME = 2000;
53    private static final int CONNECTION_TIMEOUT = 30000;
54  
55    private boolean started;
56  
57    /** The default port. If zero, we use a random port. */
58    private int defaultClientPort = 0;
59  
60    private int clientPort;
61  
62    private List<NIOServerCnxnFactory> standaloneServerFactoryList;
63    private List<ZooKeeperServer> zooKeeperServers;
64    private List<Integer> clientPortList;
65  
66    private int activeZKServerIndex;
67    private int tickTime = 0;
68  
69    private Configuration configuration;
70  
71    public MiniZooKeeperCluster() {
72      this(new Configuration());
73    }
74  
75    public MiniZooKeeperCluster(Configuration configuration) {
76      this.started = false;
77      this.configuration = configuration;
78      activeZKServerIndex = -1;
79      zooKeeperServers = new ArrayList<ZooKeeperServer>();
80      clientPortList = new ArrayList<Integer>();
81      standaloneServerFactoryList = new ArrayList<NIOServerCnxnFactory>();
82    }
83  
84    public void setDefaultClientPort(int clientPort) {
85      if (clientPort <= 0) {
86        throw new IllegalArgumentException("Invalid default ZK client port: "
87            + clientPort);
88      }
89      this.defaultClientPort = clientPort;
90    }
91  
92    /**
93     * Selects a ZK client port. Returns the default port if specified.
94     * Otherwise, returns a random port. The random port is selected from the
95     * range between 49152 to 65535. These ports cannot be registered with IANA
96     * and are intended for dynamic allocation (see http://bit.ly/dynports).
97     */
98    private int selectClientPort() {
99      if (defaultClientPort > 0) {
100       return defaultClientPort;
101     }
102     return 0xc000 + new Random().nextInt(0x3f00);
103   }
104 
105   public void setTickTime(int tickTime) {
106     this.tickTime = tickTime;
107   }
108 
109   public int getBackupZooKeeperServerNum() {
110     return zooKeeperServers.size()-1;
111   }
112 
113   public int getZooKeeperServerNum() {
114     return zooKeeperServers.size();
115   }
116 
117   // / XXX: From o.a.zk.t.ClientBase
118   private static void setupTestEnv() {
119     // during the tests we run with 100K prealloc in the logs.
120     // on windows systems prealloc of 64M was seen to take ~15seconds
121     // resulting in test failure (client timeout on first session).
122     // set env and directly in order to handle static init/gc issues
123     System.setProperty("zookeeper.preAllocSize", "100");
124     FileTxnLog.setPreallocSize(100 * 1024);
125   }
126 
127   public int startup(File baseDir) throws IOException, InterruptedException {
128     return startup(baseDir,1);
129   }
130 
131   /**
132    * @param baseDir
133    * @param numZooKeeperServers
134    * @return ClientPort server bound to.
135    * @throws IOException
136    * @throws InterruptedException
137    */
138   public int startup(File baseDir, int numZooKeeperServers) throws IOException,
139       InterruptedException {
140     if (numZooKeeperServers <= 0)
141       return -1;
142 
143     setupTestEnv();
144     shutdown();
145 
146     int tentativePort = selectClientPort();
147 
148     // running all the ZK servers
149     for (int i = 0; i < numZooKeeperServers; i++) {
150       File dir = new File(baseDir, "zookeeper_"+i).getAbsoluteFile();
151       recreateDir(dir);
152       int tickTimeToUse;
153       if (this.tickTime > 0) {
154         tickTimeToUse = this.tickTime;
155       } else {
156         tickTimeToUse = TICK_TIME;
157       }
158       ZooKeeperServer server = new ZooKeeperServer(dir, dir, tickTimeToUse);
159       NIOServerCnxnFactory standaloneServerFactory;
160       while (true) {
161         try {
162           standaloneServerFactory = new NIOServerCnxnFactory();
163           standaloneServerFactory.configure(
164             new InetSocketAddress(tentativePort),
165             configuration.getInt(HConstants.ZOOKEEPER_MAX_CLIENT_CNXNS,
166               1000));
167         } catch (BindException e) {
168           LOG.debug("Failed binding ZK Server to client port: " +
169               tentativePort);
170           // This port is already in use, try to use another.
171           tentativePort++;
172           continue;
173         }
174         break;
175       }
176 
177       // Start up this ZK server
178       standaloneServerFactory.startup(server);
179       if (!waitForServerUp(tentativePort, CONNECTION_TIMEOUT)) {
180         throw new IOException("Waiting for startup of standalone server");
181       }
182 
183       // We have selected this port as a client port.
184       clientPortList.add(tentativePort);
185       standaloneServerFactoryList.add(standaloneServerFactory);
186       zooKeeperServers.add(server);
187     }
188 
189     // set the first one to be active ZK; Others are backups
190     activeZKServerIndex = 0;
191     started = true;
192     clientPort = clientPortList.get(activeZKServerIndex);
193     LOG.info("Started MiniZK Cluster and connect 1 ZK server " +
194         "on client port: " + clientPort);
195     return clientPort;
196   }
197 
198   private void recreateDir(File dir) throws IOException {
199     if (dir.exists()) {
200       if(!FileUtil.fullyDelete(dir)) {
201         throw new IOException("Could not delete zk base directory: " + dir);
202       }
203     }
204     try {
205       dir.mkdirs();
206     } catch (SecurityException e) {
207       throw new IOException("creating dir: " + dir, e);
208     }
209   }
210 
211   /**
212    * @throws IOException
213    */
214   public void shutdown() throws IOException {
215     if (!started) {
216       return;
217     }
218 
219     // shut down all the zk servers
220     for (int i = 0; i < standaloneServerFactoryList.size(); i++) {
221       NIOServerCnxnFactory standaloneServerFactory =
222         standaloneServerFactoryList.get(i);
223       int clientPort = clientPortList.get(i);
224 
225       standaloneServerFactory.shutdown();
226       if (!waitForServerDown(clientPort, CONNECTION_TIMEOUT)) {
227         throw new IOException("Waiting for shutdown of standalone server");
228       }
229     }
230     for (ZooKeeperServer zkServer: zooKeeperServers) {
231       //explicitly close ZKDatabase since ZookeeperServer does not close them
232       zkServer.getZKDatabase().close();
233     }
234 
235     // clear everything
236     started = false;
237     activeZKServerIndex = 0;
238     standaloneServerFactoryList.clear();
239     clientPortList.clear();
240     zooKeeperServers.clear();
241 
242     LOG.info("Shutdown MiniZK cluster with all ZK servers");
243   }
244 
245   /**@return clientPort return clientPort if there is another ZK backup can run
246    *         when killing the current active; return -1, if there is no backups.
247    * @throws IOException
248    * @throws InterruptedException
249    */
250   public int killCurrentActiveZooKeeperServer() throws IOException,
251                                         InterruptedException {
252     if (!started || activeZKServerIndex < 0 ) {
253       return -1;
254     }
255 
256     // Shutdown the current active one
257     NIOServerCnxnFactory standaloneServerFactory =
258       standaloneServerFactoryList.get(activeZKServerIndex);
259     int clientPort = clientPortList.get(activeZKServerIndex);
260 
261     standaloneServerFactory.shutdown();
262     if (!waitForServerDown(clientPort, CONNECTION_TIMEOUT)) {
263       throw new IOException("Waiting for shutdown of standalone server");
264     }
265 
266     // remove the current active zk server
267     standaloneServerFactoryList.remove(activeZKServerIndex);
268     clientPortList.remove(activeZKServerIndex);
269     zooKeeperServers.remove(activeZKServerIndex);
270     LOG.info("Kill the current active ZK servers in the cluster " +
271         "on client port: " + clientPort);
272 
273     if (standaloneServerFactoryList.size() == 0) {
274       // there is no backup servers;
275       return -1;
276     }
277     clientPort = clientPortList.get(activeZKServerIndex);
278     LOG.info("Activate a backup zk server in the cluster " +
279         "on client port: " + clientPort);
280     // return the next back zk server's port
281     return clientPort;
282   }
283 
284   /**
285    * Kill one back up ZK servers
286    * @throws IOException
287    * @throws InterruptedException
288    */
289   public void killOneBackupZooKeeperServer() throws IOException,
290                                         InterruptedException {
291     if (!started || activeZKServerIndex < 0 ||
292         standaloneServerFactoryList.size() <= 1) {
293       return ;
294     }
295 
296     int backupZKServerIndex = activeZKServerIndex+1;
297     // Shutdown the current active one
298     NIOServerCnxnFactory standaloneServerFactory =
299       standaloneServerFactoryList.get(backupZKServerIndex);
300     int clientPort = clientPortList.get(backupZKServerIndex);
301 
302     standaloneServerFactory.shutdown();
303     if (!waitForServerDown(clientPort, CONNECTION_TIMEOUT)) {
304       throw new IOException("Waiting for shutdown of standalone server");
305     }
306 
307     // remove this backup zk server
308     standaloneServerFactoryList.remove(backupZKServerIndex);
309     clientPortList.remove(backupZKServerIndex);
310     zooKeeperServers.remove(backupZKServerIndex);
311     LOG.info("Kill one backup ZK servers in the cluster " +
312         "on client port: " + clientPort);
313   }
314 
315   // XXX: From o.a.zk.t.ClientBase
316   private static boolean waitForServerDown(int port, long timeout) {
317     long start = System.currentTimeMillis();
318     while (true) {
319       try {
320         Socket sock = new Socket("localhost", port);
321         try {
322           OutputStream outstream = sock.getOutputStream();
323           outstream.write("stat".getBytes());
324           outstream.flush();
325         } finally {
326           sock.close();
327         }
328       } catch (IOException e) {
329         return true;
330       }
331 
332       if (System.currentTimeMillis() > start + timeout) {
333         break;
334       }
335       try {
336         Thread.sleep(250);
337       } catch (InterruptedException e) {
338         // ignore
339       }
340     }
341     return false;
342   }
343 
344   // XXX: From o.a.zk.t.ClientBase
345   private static boolean waitForServerUp(int port, long timeout) {
346     long start = System.currentTimeMillis();
347     while (true) {
348       try {
349         Socket sock = new Socket("localhost", port);
350         BufferedReader reader = null;
351         try {
352           OutputStream outstream = sock.getOutputStream();
353           outstream.write("stat".getBytes());
354           outstream.flush();
355 
356           Reader isr = new InputStreamReader(sock.getInputStream());
357           reader = new BufferedReader(isr);
358           String line = reader.readLine();
359           if (line != null && line.startsWith("Zookeeper version:")) {
360             return true;
361           }
362         } finally {
363           sock.close();
364           if (reader != null) {
365             reader.close();
366           }
367         }
368       } catch (IOException e) {
369         // ignore as this is expected
370         LOG.info("server localhost:" + port + " not up " + e);
371       }
372 
373       if (System.currentTimeMillis() > start + timeout) {
374         break;
375       }
376       try {
377         Thread.sleep(250);
378       } catch (InterruptedException e) {
379         // ignore
380       }
381     }
382     return false;
383   }
384 
385   public int getClientPort() {
386     return clientPort;
387   }
388 }