elasticsearch分布式及数据的功能源码分析

private void setup(boolean addShutdownHook, Tuple<Settings, Environment> tuple) throws Exception {
     if (tuple.v1().getAsBoolean("bootstrap.mlockall", false)) {//尝试锁定内存
            Natives.tryMlockall();
        }
        tuple = setupJmx(tuple);
        NodeBuilder nodeBuilder = NodeBuilder.nodeBuilder().settings(tuple.v1()).loadConfigSettings(false);
        node = nodeBuilder.build();//初始化node
        if (addShutdownHook) {//添加关闭node的hook
            Runtime.getRuntime().addShutdownHook(new Thread() {
                @Override
                public void run() {
                    node.close();
                }
            });
        }
    }

public static void main(String[] args) {
.... 
String stage = "Initialization";//标明启动阶段用于构造错误信息。
        try {
            if (!foreground) {
                Loggers.disableConsoleLogging();
                System.out.close();
            }
            bootstrap.setup(true, tuple);
            stage = "Startup";
            bootstrap.start();//bootstrap的启动过程也就是node的启动过程
            if (!foreground) {
                System.err.close();
            }
//构造一个线程，保证bootstrap不退出，仍然可以接收命令。
            keepAliveLatch = new CountDownLatch(1); 
            // keep this thread alive (non daemon thread) until we shutdown/
            Runtime.getRuntime().addShutdownHook(new Thread() {
                @Override
                public void run() {
                    keepAliveLatch.countDown();
                }
            });
            keepAliveThread = new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        keepAliveLatch.await();
                    } catch (InterruptedException e) {
                        // bail out
                    }
                }
            }, "elasticsearch[keepAlive/" + Version.CURRENT + "]");
            keepAliveThread.setDaemon(false);
            keepAliveThread.start();
        } catch (Throwable e) {
            ESLogger logger = Loggers.getLogger(Bootstrap.class);
            if (bootstrap.node != null) {
                logger = Loggers.getLogger(Bootstrap.class, bootstrap.node.settings().get("name"));
            }
            String errorMessage = buildErrorMessage(stage, e);
            if (foreground) {
                System.err.println(errorMessage);
                System.err.flush();
            } else {
                logger.error(errorMessage);
            }
            Loggers.disableConsoleLogging();
            if (logger.isDebugEnabled()) {
                logger.debug("Exception", e);
            }
            System.exit(3);
        }