public static void main()

in client-tez/src/main/java/org/apache/tez/dag/app/RssDAGAppMaster.java [324:469]
125 lines of code
16 McCabe index (conditional complexity)

  public static void main(String[] args) {
    try {
      // We use trick way to introduce RssDAGAppMaster by the config tez.am.launch.cmd-opts.
      // It means some property which is set by command line will be ingored, so we must reload it.
      Configuration conf = new Configuration(new YarnConfiguration());
      DAGProtos.ConfigurationProto confProto =
          TezUtilsInternal.readUserSpecifiedTezConfiguration(
              System.getenv(ApplicationConstants.Environment.PWD.name()));
      TezUtilsInternal.addUserSpecifiedTezConfiguration(conf, confProto.getConfKeyValuesList());

      boolean sessionModeCliOption = false;
      boolean rollBackToLocalShuffle = false;
      String[] rollBackRemainingArgs = null;
      for (int i = 0; i < args.length; i++) {
        if (args[i].startsWith("-D")) {
          String[] property = args[i].split("=");
          if (property.length < 2) {
            System.setProperty(property[0].substring(2), "");
          } else {
            System.setProperty(property[0].substring(2), property[1]);
          }
        } else if (args[i].contains("--session") || args[i].contains("-s")) {
          sessionModeCliOption = true;
        }
        if (args[i].contains(DAGAppMaster.class.getName()) && isLocalShuffleMode(conf)) {
          rollBackToLocalShuffle = true;
          rollBackRemainingArgs = Arrays.copyOfRange(args, i + 1, args.length);
        }
      }

      // Load the log4j config is only init in static code block of LogManager, so we must
      // reconfigure.
      reconfigureLog4j();
      // if set tez.shuffle.mode = local then degenerates to the native way.
      if (rollBackToLocalShuffle) {
        // rollback to local shuffle mode.
        LOG.info(
            "Rollback to local shuffle mode, since tez.shuffle.mode = {}",
            conf.get(RssTezConfig.RSS_SHUFFLE_MODE, RssTezConfig.DEFAULT_RSS_SHUFFLE_MODE));
        DAGAppMaster.main(rollBackRemainingArgs);
        return;
      }

      // Install the tez class loader, which can be used add new resources
      TezClassLoader.setupTezClassLoader();
      Thread.setDefaultUncaughtExceptionHandler(new YarnUncaughtExceptionHandler());
      final String pid = System.getenv().get("JVM_PID");
      String containerIdStr = System.getenv(ApplicationConstants.Environment.CONTAINER_ID.name());
      String appSubmitTimeStr = System.getenv(ApplicationConstants.APP_SUBMIT_TIME_ENV);
      String clientVersion = System.getenv(TezConstants.TEZ_CLIENT_VERSION_ENV);
      if (clientVersion == null) {
        clientVersion = VersionInfo.UNKNOWN;
      }

      Objects.requireNonNull(
          appSubmitTimeStr, ApplicationConstants.APP_SUBMIT_TIME_ENV + " is null");

      ContainerId containerId = ConverterUtils.toContainerId(containerIdStr);
      ApplicationAttemptId applicationAttemptId = containerId.getApplicationAttemptId();

      String jobUserName = System.getenv(ApplicationConstants.Environment.USER.name());

      LOG.info(
          "Creating RssDAGAppMaster for "
              + "applicationId="
              + applicationAttemptId.getApplicationId()
              + ", attemptNum="
              + applicationAttemptId.getAttemptId()
              + ", AMContainerId="
              + containerId
              + ", jvmPid="
              + pid
              + ", userFromEnv="
              + jobUserName
              + ", cliSessionOption="
              + sessionModeCliOption
              + ", pwd="
              + System.getenv(ApplicationConstants.Environment.PWD.name())
              + ", localDirs="
              + System.getenv(ApplicationConstants.Environment.LOCAL_DIRS.name())
              + ", logDirs="
              + System.getenv(ApplicationConstants.Environment.LOG_DIRS.name()));

      AMPluginDescriptorProto amPluginDescriptorProto = null;
      if (confProto.hasAmPluginDescriptor()) {
        amPluginDescriptorProto = confProto.getAmPluginDescriptor();
      }

      UserGroupInformation.setConfiguration(conf);
      Credentials credentials = UserGroupInformation.getCurrentUser().getCredentials();

      TezUtilsInternal.setSecurityUtilConfigration(LOG, conf);

      String nodeHostString = System.getenv(ApplicationConstants.Environment.NM_HOST.name());
      String nodePortString = System.getenv(ApplicationConstants.Environment.NM_PORT.name());
      String nodeHttpPortString =
          System.getenv(ApplicationConstants.Environment.NM_HTTP_PORT.name());
      long appSubmitTime = Long.parseLong(appSubmitTimeStr);
      RssDAGAppMaster appMaster =
          new RssDAGAppMaster(
              applicationAttemptId,
              containerId,
              nodeHostString,
              Integer.parseInt(nodePortString),
              Integer.parseInt(nodeHttpPortString),
              new SystemClock(),
              appSubmitTime,
              sessionModeCliOption,
              System.getenv(ApplicationConstants.Environment.PWD.name()),
              TezCommonUtils.getTrimmedStrings(
                  System.getenv(ApplicationConstants.Environment.LOCAL_DIRS.name())),
              TezCommonUtils.getTrimmedStrings(
                  System.getenv(ApplicationConstants.Environment.LOG_DIRS.name())),
              clientVersion,
              credentials,
              jobUserName,
              amPluginDescriptorProto);
      ShutdownHookManager.get()
          .addShutdownHook(new DAGAppMasterShutdownHook(appMaster), SHUTDOWN_HOOK_PRIORITY);
      ShutdownHookManager.get()
          .addShutdownHook(new RssDAGAppMasterShutdownHook(appMaster), RSS_SHUTDOWN_HOOK_PRIORITY);

      // log the system properties
      if (LOG.isInfoEnabled()) {
        String systemPropsToLog = TezCommonUtils.getSystemPropertiesToLog(conf);
        if (systemPropsToLog != null) {
          LOG.info(systemPropsToLog);
        }
      }

      if (conf.getBoolean(
              RSS_AVOID_RECOMPUTE_SUCCEEDED_TASK, RSS_AVOID_RECOMPUTE_SUCCEEDED_TASK_DEFAULT)
          && conf.getBoolean(
              TEZ_AM_NODE_UNHEALTHY_RESCHEDULE_TASKS,
              TEZ_AM_NODE_UNHEALTHY_RESCHEDULE_TASKS_DEFAULT)) {
        LOG.info(
            "When rss.avoid.recompute.succeeded.task is enabled, "
                + "we can not rescheduler succeeded task on unhealthy node");
        conf.setBoolean(TEZ_AM_NODE_UNHEALTHY_RESCHEDULE_TASKS, false);
      }
      initAndStartAppMaster(appMaster, conf);
    } catch (Throwable t) {
      LOG.error("Error starting RssDAGAppMaster", t);
      System.exit(1);
    }
  }