Zookeeper启动之QuorumPeerMain

1. 通过zkServer.sh启动zookeeper时，正常指定的QuorumPeerMain作为启动主类。

2.QuorumPeerMain执行main方法，里面主要逻辑是执行initializeAndRun方法。

 public static void main(String[] args) {        QuorumPeerMain main = new QuorumPeerMain();        try {            main.initializeAndRun(args);        ....    }

3.initializeAndRun方法

  （1）通过QuorumPeerConfig.parse方法，解析配置文件

  （2）通过DatadirCleanupManager.start方法，启动清除调度任务

  （3）runFromConfig或ZooKeeperServerMain.main来启动zookkeeper

protected void initializeAndRun(String[] args)        throws ConfigException, IOException, AdminServerException    {        QuorumPeerConfig config = new QuorumPeerConfig();        if (args.length == 1) {//如果指定的配置文件            config.parse(args[0]);//解析配置文件        }        // Start and schedule the the purge task        //启动安排清除任务        DatadirCleanupManager purgeMgr = new DatadirCleanupManager(config                .getDataDir(), config.getDataLogDir(), config                .getSnapRetainCount(), config.getPurgeInterval());        purgeMgr.start();        if (args.length == 1 && config.isDistributed()) {            runFromConfig(config);//启动zookeepeer集群        } else {            LOG.warn("Either no config or no quorum defined in config, running "                    + " in standalone mode");            // there is only server in the quorum -- run as standalone            ZooKeeperServerMain.main(args);        }    }