HadoopSourceAnalyse --- Nodemanager Container FSM

overview

上图中还有一个状态变换，从killing 到 Exited_with_failure,这个变换由事件：CONTAINER_EXITED_WITH_FAILURE 触发，执行：ExitedWithFailureTransition；

INIT_CONTAINER And RESOURCE_LOCALIZED  Handle

Container 收到该事件通知后，会首先偿试启动所有的和当前App 相关的 AuxServices，

 for (Map.Entry<String,ByteBuffer> service : csd.entrySet()) {
          container.dispatcher.getEventHandler().handle(
              new AuxServicesEvent(AuxServicesEventType.APPLICATION_INIT,
                  ctxt.getUser(), container.container.getId()
                      .getApplicationAttemptId().getApplicationId(),
                  service.getKey().toString(), service.getValue()));
        }

然年请求所有与当前用户及App相关的 localization resource，然后进入localizing 状态，等待系统加载Resource，当ResourceLocalizer成功加载Resource之后，会向Container发送：RESOURCE_LOCALIZED 事件:

 for (ContainerId container : rsrc.ref) {
        rsrc.dispatcher.getEventHandler().handle(
            new ContainerResourceLocalizedEvent(
              container, rsrc.rsrc, rsrc.localPath));
      }

当所有的Resource都成功加载之后，Container向 ContainersLauncher 发送一个LAUNCH_CONTAINER事件并进入Localized状态， ContainersLauncher将用一个新的线程 去launche container：

 Application app =
          context.getApplications().get(
              containerId.getApplicationAttemptId().getApplicationId());

        ContainerLaunch launch = new ContainerLaunch(getConfig(), dispatcher,
            exec, app, event.getContainer(), dirsHandler);
        running.put(containerId,
            new RunningContainer(containerLauncher.submit(launch), 
                launch));

在新在线程中，先会替换所有的变量（主要是log相关），并用给定的命令生成一份本地执行的脚本文件，奖后向container 发送 LAUNCH_CONTAINER 事件，然后开始执行该脚本，线程会一直等到脚 本执行结束，或被Kill掉，最后返回执行结果。

 try {
        // /////////// Write out the container-script in the nmPrivate space.
        List<Path> appDirs = new ArrayList<Path>(localDirs.size());
        for (String localDir : localDirs) {
          Path usersdir = new Path(localDir, ContainerLocalizer.USERCACHE);
          Path userdir = new Path(usersdir, user);
          Path appsdir = new Path(userdir, ContainerLocalizer.APPCACHE);
          appDirs.add(new Path(appsdir, appIdStr));
        }
        containerScriptOutStream =
          lfs.create(nmPrivateContainerScriptPath,
              EnumSet.of(CREATE, OVERWRITE));

        // Set the token location too.
        environment.put(
            ApplicationConstants.CONTAINER_TOKEN_FILE_ENV_NAME, 
            new Path(containerWorkDir, 
                FINAL_CONTAINER_TOKENS_FILE).toUri().getPath());

        // Sanitize the container's environment
        sanitizeEnv(environment, containerWorkDir, appDirs, localResources);
        
        // Write out the environment
        writeLaunchEnv(containerScriptOutStream, environment, localResources,
            launchContext.getCommands());
        
        // /////////// End of writing out container-script

        // /////////// Write out the container-tokens in the nmPrivate space.
        tokensOutStream =
            lfs.create(nmPrivateTokensPath, EnumSet.of(CREATE, OVERWRITE));
        Credentials creds = container.getCredentials();
        creds.writeTokenStorageToStream(tokensOutStream);
        // /////////// End of writing out container-tokens
      } finally {
        IOUtils.cleanup(LOG, containerScriptOutStream, tokensOutStream);
      }

发送 LAUNCH_CONAINER,并启动脚 本：

      // LaunchContainer is a blocking call. We are here almost means the
      // container is launched, so send out the event.
      dispatcher.getEventHandler().handle(new ContainerEvent(
            containerID,
            ContainerEventType.CONTAINER_LAUNCHED));

      // Check if the container is signalled to be killed.
      if (!shouldLaunchContainer.compareAndSet(false, true)) {
        LOG.info("Container " + containerIdStr + " not launched as "
            + "cleanup already called");
        ret = ExitCode.TERMINATED.getExitCode();
      }
      else {
        exec.activateContainer(containerID, pidFilePath);
        ret = exec.launchContainer(container, nmPrivateContainerScriptPath,
                nmPrivateTokensPath, user, appIdStr, containerWorkDir,
                localDirs, logDirs);
      }

LAUNCH_CONTAINER Handle

收到该事件之后，通产ContainerMonitor 监 视该container的执行。

For other complete event just ignore here；