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1   /*
2    *
3    * Licensed to the Apache Software Foundation (ASF) under one
4    * or more contributor license agreements.  See the NOTICE file
5    * distributed with this work for additional information
6    * regarding copyright ownership.  The ASF licenses this file
7    * to you under the Apache License, Version 2.0 (the
8    * "License"); you may not use this file except in compliance
9    * with the License.  You may obtain a copy of the License at
10   *
11   *     http://www.apache.org/licenses/LICENSE-2.0
12   *
13   * Unless required by applicable law or agreed to in writing, software
14   * distributed under the License is distributed on an "AS IS" BASIS,
15   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16   * See the License for the specific language governing permissions and
17   * limitations under the License.
18   */
19  package org.apache.hadoop.hbase.zookeeper;
20  
21  import java.io.BufferedReader;
22  import java.io.File;
23  import java.io.IOException;
24  import java.io.InputStreamReader;
25  import java.io.OutputStream;
26  import java.io.Reader;
27  import java.net.BindException;
28  import java.net.InetSocketAddress;
29  import java.net.Socket;
30  import java.util.ArrayList;
31  import java.util.List;
32  import java.util.Random;
33  
34  import org.apache.commons.logging.Log;
35  import org.apache.commons.logging.LogFactory;
36  import org.apache.hadoop.classification.InterfaceAudience;
37  import org.apache.hadoop.classification.InterfaceStability;
38  import org.apache.hadoop.conf.Configuration;
39  import org.apache.hadoop.fs.FileUtil;
40  import org.apache.hadoop.hbase.HConstants;
41  import org.apache.zookeeper.server.NIOServerCnxnFactory;
42  import org.apache.zookeeper.server.ZooKeeperServer;
43  import org.apache.zookeeper.server.persistence.FileTxnLog;
44  
45  /**
46   * TODO: Most of the code in this class is ripped from ZooKeeper tests. Instead
47   * of redoing it, we should contribute updates to their code which let us more
48   * easily access testing helper objects.
49   */
50  @InterfaceAudience.Public
51  @InterfaceStability.Evolving
52  public class MiniZooKeeperCluster {
53    private static final Log LOG = LogFactory.getLog(MiniZooKeeperCluster.class);
54  
55    private static final int TICK_TIME = 2000;
56    private static final int CONNECTION_TIMEOUT = 30000;
57  
58    private boolean started;
59  
60    /** The default port. If zero, we use a random port. */
61    private int defaultClientPort = 0;
62  
63    private int clientPort;
64  
65    private List<NIOServerCnxnFactory> standaloneServerFactoryList;
66    private List<ZooKeeperServer> zooKeeperServers;
67    private List<Integer> clientPortList;
68  
69    private int activeZKServerIndex;
70    private int tickTime = 0;
71  
72    private Configuration configuration;
73  
74    public MiniZooKeeperCluster() {
75      this(new Configuration());
76    }
77  
78    public MiniZooKeeperCluster(Configuration configuration) {
79      this.started = false;
80      this.configuration = configuration;
81      activeZKServerIndex = -1;
82      zooKeeperServers = new ArrayList<ZooKeeperServer>();
83      clientPortList = new ArrayList<Integer>();
84      standaloneServerFactoryList = new ArrayList<NIOServerCnxnFactory>();
85    }
86  
87    public void setDefaultClientPort(int clientPort) {
88      if (clientPort <= 0) {
89        throw new IllegalArgumentException("Invalid default ZK client port: "
90            + clientPort);
91      }
92      this.defaultClientPort = clientPort;
93    }
94  
95    /**
96     * Selects a ZK client port. Returns the default port if specified.
97     * Otherwise, returns a random port. The random port is selected from the
98     * range between 49152 to 65535. These ports cannot be registered with IANA
99     * and are intended for dynamic allocation (see http://bit.ly/dynports).
100    */
101   private int selectClientPort() {
102     if (defaultClientPort > 0) {
103       return defaultClientPort;
104     }
105     return 0xc000 + new Random().nextInt(0x3f00);
106   }
107 
108   public void setTickTime(int tickTime) {
109     this.tickTime = tickTime;
110   }
111 
112   public int getBackupZooKeeperServerNum() {
113     return zooKeeperServers.size()-1;
114   }
115 
116   public int getZooKeeperServerNum() {
117     return zooKeeperServers.size();
118   }
119 
120   // / XXX: From o.a.zk.t.ClientBase
121   private static void setupTestEnv() {
122     // during the tests we run with 100K prealloc in the logs.
123     // on windows systems prealloc of 64M was seen to take ~15seconds
124     // resulting in test failure (client timeout on first session).
125     // set env and directly in order to handle static init/gc issues
126     System.setProperty("zookeeper.preAllocSize", "100");
127     FileTxnLog.setPreallocSize(100 * 1024);
128   }
129 
130   public int startup(File baseDir) throws IOException, InterruptedException {
131     return startup(baseDir,1);
132   }
133 
134   /**
135    * @param baseDir
136    * @param numZooKeeperServers
137    * @return ClientPort server bound to.
138    * @throws IOException
139    * @throws InterruptedException
140    */
141   public int startup(File baseDir, int numZooKeeperServers) throws IOException,
142       InterruptedException {
143     if (numZooKeeperServers <= 0)
144       return -1;
145 
146     setupTestEnv();
147     shutdown();
148 
149     int tentativePort = selectClientPort();
150 
151     // running all the ZK servers
152     for (int i = 0; i < numZooKeeperServers; i++) {
153       File dir = new File(baseDir, "zookeeper_"+i).getAbsoluteFile();
154       recreateDir(dir);
155       int tickTimeToUse;
156       if (this.tickTime > 0) {
157         tickTimeToUse = this.tickTime;
158       } else {
159         tickTimeToUse = TICK_TIME;
160       }
161       ZooKeeperServer server = new ZooKeeperServer(dir, dir, tickTimeToUse);
162       NIOServerCnxnFactory standaloneServerFactory;
163       while (true) {
164         try {
165           standaloneServerFactory = new NIOServerCnxnFactory();
166           standaloneServerFactory.configure(
167             new InetSocketAddress(tentativePort),
168             configuration.getInt(HConstants.ZOOKEEPER_MAX_CLIENT_CNXNS,
169               1000));
170         } catch (BindException e) {
171           LOG.debug("Failed binding ZK Server to client port: " +
172               tentativePort);
173           // This port is already in use, try to use another.
174           tentativePort = selectClientPort();
175           continue;
176         }
177         break;
178       }
179 
180       // Start up this ZK server
181       standaloneServerFactory.startup(server);
182       if (!waitForServerUp(tentativePort, CONNECTION_TIMEOUT)) {
183         throw new IOException("Waiting for startup of standalone server");
184       }
185 
186       // We have selected this port as a client port.
187       clientPortList.add(tentativePort);
188       standaloneServerFactoryList.add(standaloneServerFactory);
189       zooKeeperServers.add(server);
190       tentativePort++; //for the next server
191     }
192 
193     // set the first one to be active ZK; Others are backups
194     activeZKServerIndex = 0;
195     started = true;
196     clientPort = clientPortList.get(activeZKServerIndex);
197     LOG.info("Started MiniZK Cluster and connect 1 ZK server " +
198         "on client port: " + clientPort);
199     return clientPort;
200   }
201 
202   private void recreateDir(File dir) throws IOException {
203     if (dir.exists()) {
204       if(!FileUtil.fullyDelete(dir)) {
205         throw new IOException("Could not delete zk base directory: " + dir);
206       }
207     }
208     try {
209       dir.mkdirs();
210     } catch (SecurityException e) {
211       throw new IOException("creating dir: " + dir, e);
212     }
213   }
214 
215   /**
216    * @throws IOException
217    */
218   public void shutdown() throws IOException {
219     if (!started) {
220       return;
221     }
222 
223     // shut down all the zk servers
224     for (int i = 0; i < standaloneServerFactoryList.size(); i++) {
225       NIOServerCnxnFactory standaloneServerFactory =
226         standaloneServerFactoryList.get(i);
227       int clientPort = clientPortList.get(i);
228 
229       standaloneServerFactory.shutdown();
230       if (!waitForServerDown(clientPort, CONNECTION_TIMEOUT)) {
231         throw new IOException("Waiting for shutdown of standalone server");
232       }
233     }
234     for (ZooKeeperServer zkServer: zooKeeperServers) {
235       //explicitly close ZKDatabase since ZookeeperServer does not close them
236       zkServer.getZKDatabase().close();
237     }
238 
239     // clear everything
240     started = false;
241     activeZKServerIndex = 0;
242     standaloneServerFactoryList.clear();
243     clientPortList.clear();
244     zooKeeperServers.clear();
245 
246     LOG.info("Shutdown MiniZK cluster with all ZK servers");
247   }
248 
249   /**@return clientPort return clientPort if there is another ZK backup can run
250    *         when killing the current active; return -1, if there is no backups.
251    * @throws IOException
252    * @throws InterruptedException
253    */
254   public int killCurrentActiveZooKeeperServer() throws IOException,
255                                         InterruptedException {
256     if (!started || activeZKServerIndex < 0 ) {
257       return -1;
258     }
259 
260     // Shutdown the current active one
261     NIOServerCnxnFactory standaloneServerFactory =
262       standaloneServerFactoryList.get(activeZKServerIndex);
263     int clientPort = clientPortList.get(activeZKServerIndex);
264 
265     standaloneServerFactory.shutdown();
266     if (!waitForServerDown(clientPort, CONNECTION_TIMEOUT)) {
267       throw new IOException("Waiting for shutdown of standalone server");
268     }
269 
270     // remove the current active zk server
271     standaloneServerFactoryList.remove(activeZKServerIndex);
272     clientPortList.remove(activeZKServerIndex);
273     zooKeeperServers.remove(activeZKServerIndex);
274     LOG.info("Kill the current active ZK servers in the cluster " +
275         "on client port: " + clientPort);
276 
277     if (standaloneServerFactoryList.size() == 0) {
278       // there is no backup servers;
279       return -1;
280     }
281     clientPort = clientPortList.get(activeZKServerIndex);
282     LOG.info("Activate a backup zk server in the cluster " +
283         "on client port: " + clientPort);
284     // return the next back zk server's port
285     return clientPort;
286   }
287 
288   /**
289    * Kill one back up ZK servers
290    * @throws IOException
291    * @throws InterruptedException
292    */
293   public void killOneBackupZooKeeperServer() throws IOException,
294                                         InterruptedException {
295     if (!started || activeZKServerIndex < 0 ||
296         standaloneServerFactoryList.size() <= 1) {
297       return ;
298     }
299 
300     int backupZKServerIndex = activeZKServerIndex+1;
301     // Shutdown the current active one
302     NIOServerCnxnFactory standaloneServerFactory =
303       standaloneServerFactoryList.get(backupZKServerIndex);
304     int clientPort = clientPortList.get(backupZKServerIndex);
305 
306     standaloneServerFactory.shutdown();
307     if (!waitForServerDown(clientPort, CONNECTION_TIMEOUT)) {
308       throw new IOException("Waiting for shutdown of standalone server");
309     }
310 
311     // remove this backup zk server
312     standaloneServerFactoryList.remove(backupZKServerIndex);
313     clientPortList.remove(backupZKServerIndex);
314     zooKeeperServers.remove(backupZKServerIndex);
315     LOG.info("Kill one backup ZK servers in the cluster " +
316         "on client port: " + clientPort);
317   }
318 
319   // XXX: From o.a.zk.t.ClientBase
320   private static boolean waitForServerDown(int port, long timeout) {
321     long start = System.currentTimeMillis();
322     while (true) {
323       try {
324         Socket sock = new Socket("localhost", port);
325         try {
326           OutputStream outstream = sock.getOutputStream();
327           outstream.write("stat".getBytes());
328           outstream.flush();
329         } finally {
330           sock.close();
331         }
332       } catch (IOException e) {
333         return true;
334       }
335 
336       if (System.currentTimeMillis() > start + timeout) {
337         break;
338       }
339       try {
340         Thread.sleep(250);
341       } catch (InterruptedException e) {
342         // ignore
343       }
344     }
345     return false;
346   }
347 
348   // XXX: From o.a.zk.t.ClientBase
349   private static boolean waitForServerUp(int port, long timeout) {
350     long start = System.currentTimeMillis();
351     while (true) {
352       try {
353         Socket sock = new Socket("localhost", port);
354         BufferedReader reader = null;
355         try {
356           OutputStream outstream = sock.getOutputStream();
357           outstream.write("stat".getBytes());
358           outstream.flush();
359 
360           Reader isr = new InputStreamReader(sock.getInputStream());
361           reader = new BufferedReader(isr);
362           String line = reader.readLine();
363           if (line != null && line.startsWith("Zookeeper version:")) {
364             return true;
365           }
366         } finally {
367           sock.close();
368           if (reader != null) {
369             reader.close();
370           }
371         }
372       } catch (IOException e) {
373         // ignore as this is expected
374         LOG.info("server localhost:" + port + " not up " + e);
375       }
376 
377       if (System.currentTimeMillis() > start + timeout) {
378         break;
379       }
380       try {
381         Thread.sleep(250);
382       } catch (InterruptedException e) {
383         // ignore
384       }
385     }
386     return false;
387   }
388 
389   public int getClientPort() {
390     return clientPort;
391   }
392 }