我对OpenTSDB的一些理解——服务启动过程

public static void main(String[] args) throws IOException {
    Logger log = LoggerFactory.getLogger(TSDMain.class);
    log.info("Starting.");
    log.info(BuildData.revisionString());
    log.info(BuildData.buildString());
    try {
      System.in.close();  // Release a FD we don't need.
    } catch (Exception e) {
      log.warn("Failed to close stdin", e);
    }

    final ArgP argp = new ArgP();
    CliOptions.addCommon(argp);
    argp.addOption("--port", "NUM", "TCP port to listen on.");
    ...
    CliOptions.addAutoMetricFlag(argp);
    args = CliOptions.parse(argp, args);
    args = null; // free().

    // get a config object
    Config config = CliOptions.getConfig(argp);
    
    // check for the required parameters
    ...

    final ServerSocketChannelFactory factory;
    int connections_limit = ;
    try {
      connections_limit = config.getInt("tsd.core.connections.limit");
    } catch (NumberFormatException nfe) {
      usage(argp, "Invalid connections limit", 1);
    }
    if (config.getBoolean("tsd.network.async_io")) {
      int workers = Runtime.getRuntime().availableProcessors() * 2;
      if (config.hasProperty("tsd.network.worker_threads")) {
        try {
        workers = config.getInt("tsd.network.worker_threads");
        } catch (NumberFormatException nfe) {
          usage(argp, "Invalid worker thread count", 1);
        }
      }
      final Executor executor = Executors.newCachedThreadPool();
      final NioServerBossPool boss_pool = 
          new NioServerBossPool(executor, 1, new Threads.BossThreadNamer());
      final NioWorkerPool worker_pool = new NioWorkerPool(executor, 
          workers, new Threads.WorkerThreadNamer());
      factory = new NioServerSocketChannelFactory(boss_pool, worker_pool);
    } else {
      factory = new OioServerSocketChannelFactory(
          Executors.newCachedThreadPool(), Executors.newCachedThreadPool(), 
          new Threads.PrependThreadNamer());
    }

    ...

    try {
      tsdb = new TSDB(config);
      if (startup != null) {
        tsdb.setStartupPlugin(startup);
      }
      tsdb.initializePlugins(true);
      if (config.getBoolean("tsd.storage.hbase.prefetch_meta")) {
        tsdb.preFetchHBaseMeta();
      }
      
      // Make sure we don't even start if we can't find our tables.
      tsdb.checkNecessaryTablesExist().joinUninterruptibly();
      
      registerShutdownHook();
      final ServerBootstrap server = new ServerBootstrap(factory);
      
      // This manager is capable of lazy init, but we force an init
      // here to fail fast.
      final RpcManager manager = RpcManager.instance(tsdb);

      server.setPipelineFactory(new PipelineFactory(tsdb, manager, connections_limit));
      if (config.hasProperty("tsd.network.backlog")) {
        server.setOption("backlog", config.getInt("tsd.network.backlog")); 
      }
      server.setOption("child.tcpNoDelay", 
          config.getBoolean("tsd.network.tcp_no_delay"));
      server.setOption("child.keepAlive", 
          config.getBoolean("tsd.network.keep_alive"));
      server.setOption("reuseAddress", 
          config.getBoolean("tsd.network.reuse_address"));

      // null is interpreted as the wildcard address.
      InetAddress bindAddress = null;
      if (config.hasProperty("tsd.network.bind")) {
        bindAddress = InetAddress.getByName(config.getString("tsd.network.bind"));
      }

      // we validated the network port config earlier
      final InetSocketAddress addr = new InetSocketAddress(bindAddress,
          config.getInt("tsd.network.port"));
      server.bind(addr);
      if (startup != null) {
        startup.setReady(tsdb);
      }
      log.info("Ready to serve on " + addr);
    } catch (Throwable e) {
      factory.releaseExternalResources();
      try {
        if (tsdb != null)
          tsdb.shutdown().joinUninterruptibly();
      } catch (Exception e2) {
        log.error("Failed to shutdown HBase client", e2);
      }
      throw new RuntimeException("Initialization failed", e);
    }
    // The server is now running in separate threads, we can exit main.
  }