TimeTunnel ZooKeeperServer

通过自带的ZooKeeperServerForTest对ZooKeeperServer进行测试

/**   * 测试ZooKeeperServer   */  private static final Logger LOG =        Logger.getLogger(ZooKeeperServerMain.class);  private NIOServerCnxn.Factory cnxnFactory;public static void main(String[] args) {  ServerConfig config = new ServerConfig();    if (args.length == 1) {        try {config.parse(args[0]);} catch (ConfigException e) {e.printStackTrace();}    } else {        config.parse(args);    }  try { //args[0]=8020,args[1]="d:\\",args[2]=1000new ZooKeeperServerForTest(8020,"d:\\",1000).test(args,config);} catch (IOException e) {e.printStackTrace();}}public void test(String[] args,ServerConfig config) throws IOException{      LOG.info("Starting server");    try {        // Note that this thread isn't going to be doing anything else,        // so rather than spawning another thread, we will just call        // run() in this thread.        // create a file logger url from the command line args        ZooKeeperServer zkServer = new ZooKeeperServer();        FileTxnSnapLog ftxn = new FileTxnSnapLog(new               File(config.getDataLogDir()), new File(config.getDataDir()));        zkServer.setTxnLogFactory(ftxn);        zkServer.setTickTime(config.getTickTime());        zkServer.setMinSessionTimeout(config.getMinSessionTimeout());        zkServer.setMaxSessionTimeout(config.getMaxSessionTimeout());        cnxnFactory = new NIOServerCnxn.Factory(config.getClientPortAddress(),                config.getMaxClientCnxns());        cnxnFactory.startup(zkServer);        cnxnFactory.join();        if (zkServer.isRunning()) {            zkServer.shutdown();        }    } catch (InterruptedException e) {        // warn, but generally this is ok        LOG.warn("Server interrupted", e);    }}

运行结果：

12/12/07 11:31:07 INFO server.ZooKeeperServerMain: Starting server12/12/07 11:31:07 INFO server.ZooKeeperServer: Server environment:zookeeper.version=3.3.2-1031432, built on 11/05/2010 05:32 GMT12/12/07 11:31:07 INFO server.ZooKeeperServer: Server environment:host.name=2S4PKZGC5RFRU9Z12/12/07 11:31:07 INFO server.ZooKeeperServer: Server environment:java.version=1.7.0_0712/12/07 11:31:07 INFO server.ZooKeeperServer: Server environment:java.vendor=Oracle Corporation12/12/07 11:31:07 INFO server.ZooKeeperServer: Server environment:java.home=C:\Program Files (x86)\Java\jre712/12/07 11:31:07 INFO server.ZooKeeperServer: Server environment:java.class.path=F:\workspace\timetunnel\bin;E:\TimeTunnel\apps\dfswriter\lib\commons-io-1.4.jar;E:\TimeTunnel\apps\dfswriter\lib\commons-pool-1.4.jar;E:\TimeTunnel\apps\dfswriter\lib\FilterApi.jar;E:\TimeTunnel\apps\dfswriter\lib\hadoop-0.19.2-core.jar;E:\TimeTunnel\apps\dfswriter\lib\hadoop-0.20.2-core.jar;E:\TimeTunnel\apps\dfswriter\lib\hbase-0.90.3.jar;E:\TimeTunnel\apps\dfswriter\lib\libthrift-0.5.0-20100116.jar;E:\TimeTunnel\apps\dfswriter\lib\libthrift-0.7.0.jar;E:\TimeTunnel\apps\dfswriter\lib\quartz-all-1.8.3.jar;E:\TimeTunnel\apps\dfswriter\lib\TTClient.jar;E:\TimeTunnel\apps\dfswriter\lib\zookeeper-3.3.2.jar;E:\TimeTunnel\apps\savefile\lib\libthrift-0.5.0-20100116.jar;E:\TimeTunnel\apps\savefile\lib\quartz-all-1.8.3.jar;E:\TimeTunnel\idl\lib\javax.jms_1.1.0.jar;E:\TimeTunnel\idl\lib\jmxri-1.2.1.jar;E:\TimeTunnel\idl\lib\jmxtools-1.2.1.jar;E:\TimeTunnel\idl\lib\libthrift-0.5.0-20100116.jar;E:\TimeTunnel\router\lib\libthrift-0.5.0.jar;E:\TimeTunnel\router\lib\timetunnel2-cluster-0.1.0.jar;E:\TimeTunnel\router\lib\zk-recipes.jar;E:\TimeTunnel\router\lib\zookeeper-3.2.2.jar;E:\eclipselib\junit-4.11.jar;E:\eclipselib\zookeeper-3.3.5.jar;E:\eclipse\plugins\org.apache.log4j_1.2.15.v201012070815.jar12/12/07 11:31:07 INFO server.ZooKeeperServer: Server environment:java.library.path=C:\Program Files (x86)\Java\jre7\bin;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:\Windows;C:/Program Files (x86)/Java/jre7/bin/client;C:/Program Files (x86)/Java/jre7/bin;C:/Program Files (x86)/Java/jre7/lib/i386;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\Windows7Master;E:\Program Files\TortoiseSVN\bin;C:\Program Files (x86)\Java\jdk1.7.0_07/bin;C:\Program Files (x86)\Java\jdk1.7.0_07/jre/bin;D:\apache-ant-1.8.4\bin;$ANT_HOME\bin;$HADOOP_HOME\bin;E:\eclipse;;.12/12/07 11:31:07 INFO server.ZooKeeperServer: Server environment:java.io.tmpdir=C:\Users\ADMINI~1\AppData\Local\Temp\12/12/07 11:31:07 INFO server.ZooKeeperServer: Server environment:java.compiler=<NA>12/12/07 11:31:07 INFO server.ZooKeeperServer: Server environment:os.name=Windows 712/12/07 11:31:07 INFO server.ZooKeeperServer: Server environment:os.arch=x8612/12/07 11:31:07 INFO server.ZooKeeperServer: Server environment:os.version=6.112/12/07 11:31:07 INFO server.ZooKeeperServer: Server environment:user.name=Administrator12/12/07 11:31:07 INFO server.ZooKeeperServer: Server environment:user.home=C:\Users\Administrator12/12/07 11:31:07 INFO server.ZooKeeperServer: Server environment:user.dir=F:\workspace\timetunnel12/12/07 11:31:07 INFO server.ZooKeeperServer: tickTime set to 100012/12/07 11:31:07 INFO server.ZooKeeperServer: minSessionTimeout set to -112/12/07 11:31:07 INFO server.ZooKeeperServer: maxSessionTimeout set to -112/12/07 11:31:07 INFO server.NIOServerCnxn: binding to port 0.0.0.0/0.0.0.0:802012/12/07 11:31:07 INFO persistence.FileSnap: Reading snapshot d:\version-2\snapshot.012/12/07 11:31:07 INFO persistence.FileTxnSnapLog: Snapshotting: 0

执行完成后会在d:下面生成version-2文件夹和snapshot.0文件

具体执行过程是：

 1.对new NIOServerCnxn.Factory(config.getClientPortAddress(),config.getMaxClientCnxns());一个绑定端口的

public Factory(InetSocketAddress addr, int maxcc) throws IOException {            super("NIOServerCxn.Factory:" + addr);            setDaemon(true);            maxClientCnxns = maxcc;            this.ss = ServerSocketChannel.open();            ss.socket().setReuseAddress(true);            LOG.info("binding to port " + addr);            ss.socket().bind(addr);            ss.configureBlocking(false);            ss.register(selector, SelectionKey.OP_ACCEPT);        }

2.对cnxnFactory.startup(zkServer);进行分析  跳转到org.apache.zookeeper.server.NIOServerCnxn

public void startup(ZooKeeperServer zks) throws IOException,                InterruptedException {            start();//启动线程            zks.startdata();//创建文件夹和文件            zks.startup();            setZooKeeperServer(zks);        }

3.对org.apache.zookeeper.server.NIOServerCnxn.startup(zks)里面的zks.startdata()进行分析 跳转到org.apache.zookeeper.server.ZooKeeperServer

public void startdata()     throws IOException, InterruptedException {        //check to see if zkDb is not null        if (zkDb == null) {            zkDb = new ZKDatabase(this.txnLogFactory);        }          if (!zkDb.isInitialized()) {            loadData();//创建文件夹和文件        }    }

4.对org.apache.zookeeper.server.ZooKeeperServer.startdata()内的zkDb = new ZKDatabase(this.txnLogFactory)进行分析，跳转到org.apache.zookeeper.server.ZKDatabase

public ZKDatabase(FileTxnSnapLog snapLog) {        dataTree = new DataTree();        sessionsWithTimeouts = new ConcurrentHashMap<Long, Integer>();        this.snapLog = snapLog;    }

5.对org.apache.zookeeper.server.ZooKeeperServer.startdata()内的loadData()进行分析，跳转到相同类的loadData()方法中

/**     *  Restore sessions and data     */    public void loadData() throws IOException, InterruptedException {        setZxid(zkDb.loadDataBase());        // Clean up dead sessions        LinkedList<Long> deadSessions = new LinkedList<Long>();        for (long session : zkDb.getSessions()) {          if (zkDb.getSessionWithTimeOuts().get(session) == null) {                deadSessions.add(session);            }        }        zkDb.setDataTreeInit(true);        for (long session : deadSessions) {            // XXX: Is lastProcessedZxid really the best thing to use?            killSession(session, zkDb.getDataTreeLastProcessedZxid());        }        // Make a clean snapshot        takeSnapshot();//保存日志信息    }

6.对org.apache.zookeeper.server.ZooKeeperServer.loadData()内的takeSnapshot()进行分析，跳转到相同类的takeSnapshot()方法中

public void takeSnapshot(){        try {            txnLogFactory.save(zkDb.getDataTree(), zkDb.getSessionWithTimeOuts()); //通过FileTxnSnapLog(文本文件快照日志类)的保存方法保存到相应的文件中，做日志信息的持久化操作        } catch (IOException e) {            LOG.fatal("Severe unrecoverable error, exiting", e);            // This is a severe error that we cannot recover from,            // so we need to exit            System.exit(10);        }    }

7.对org.apache.zookeeper.server.ZooKeeperServer.takeSnapshot()内的txnLogFactory.save(zkDb.getDataTree(), zkDb.getSessionWithTimeOuts())进行分析，跳转到相同类的org.apache.zookeeper.server.persistence.FileTxnSnapLog.save()方法中

 public void save(DataTree dataTree,            ConcurrentHashMap<Long, Integer> sessionsWithTimeouts)        throws IOException {        long lastZxid = dataTree.lastProcessedZxid; //默认是0，值是取ProcessTxnResult.TxnHeader.zxid不确定是什么东西        LOG.info("Snapshotting: " + Long.toHexString(lastZxid));        File snapshot=new File(                snapDir, Util.makeSnapshotName(lastZxid)); //snapDir具体取值看8.的解释  snap="d:\\version-2\\"        snapLog.serialize(dataTree, sessionsWithTimeouts, snapshot); //写数据            }

8.snapDir:是通过ZooKeeperServerForTest.test(String[] args,ServerConfig config)【用来测试的方法】中的FileTxnSnapLog ftxn = new FileTxnSnapLog(new File(config.getDataLogDir()), new File(config.getDataDir()));就已经生成的,而其中的dataLogDir=dataDir="d:\\",下面是实现源码org.apache.zookeeper.server.ServerConfig.parse(String[] args)，配置config

public void parse(String[] args) {//输入的参数是args[] = {8020,"d:\\",1000}        if (args.length < 2 || args.length > 4) {            throw new IllegalArgumentException("Invalid args:"                    + Arrays.toString(args));        }        clientPortAddress = new InetSocketAddress(Integer.parseInt(args[0])); //0.0.0.0/0.0.0.0:8020        dataDir = args[1];//args[1]="d:\\"        dataLogDir = dataDir;        if (args.length == 3) {            tickTime = Integer.parseInt(args[2]);        }        if (args.length == 4) {            maxClientCnxns = Integer.parseInt(args[3]);        }    }

下面是org.apache.zookeeper.server.persistence.FileTxnSnapLog(File dataDir, File snapDir)源码，生成snapDir

public FileTxnSnapLog(File dataDir, File snapDir) throws IOException {        this.dataDir = new File(dataDir, version + VERSION);  //VERSION:public final static int VERSION = 2;        this.snapDir = new File(snapDir, version + VERSION);  //version:public final static String version = "version-";        if (!this.dataDir.exists()) {            if (!this.dataDir.mkdirs()) {                throw new IOException("Unable to create data directory "                        + this.dataDir);            }        }        if (!this.snapDir.exists()) {            if (!this.snapDir.mkdirs()) {                throw new IOException("Unable to create snap directory "                        + this.snapDir);            }        }        txnLog = new FileTxnLog(this.dataDir);        snapLog = new FileSnap(this.snapDir);    }

9.我们现在要分析一下7.中的Util.makeSnapshotName(lastZxid)方法的作用，跳转到org.apache.zookeeper.server.persistence.Util.makeSnapshotName(long zxid)

/**     * Creates a snapshot file name.     *      * @param zxid used as a suffix     * @return file name     */    public static String makeSnapshotName(long zxid) {        return "snapshot." + Long.toHexString(zxid);//snapshot.0    }

到这来，文件夹及文件都创建好了

 下面看下数据的生成数的生成就是直接new DataTree()生成了一个

  ''（/）//空字符串或"/"作为根的节点

   ........../zookeeper //一级子节点

             ........../quota           //全路径是   /zookeeper/quota

public DataTree() {        /* Rather than fight it, let root have an alias */        nodes.put("", root);        nodes.put(rootZookeeper, root);        /** add the proc node and quota node */        root.addChild(procChildZookeeper);        nodes.put(procZookeeper, procDataNode);        procDataNode.addChild(quotaChildZookeeper);        nodes.put(quotaZookeeper, quotaDataNode);    }

生成完了DataTree()的数据后通过  7. 中的  snapLog.serialize(dataTree, sessionsWithTimeouts, snapshot);//写数据

 

调用到new DataTree()的方法的地方在 3.  zkDb = new ZKDatabase(this.txnLogFactory);

public ZKDatabase(FileTxnSnapLog snapLog) {        dataTree = new DataTree();        sessionsWithTimeouts = new ConcurrentHashMap<Long, Integer>();        this.snapLog = snapLog;    }

目前就分析到这来，生成的文件数据内容