SparkContext

sparkcontext：

Spark功能的主要入口。SparkContext表示与Spark集群的连接，可以用来在该集群上创建rdd、accumulator和broadcast变量。

  private var _conf: SparkConf = _
  private var _eventLogDir: Option[URI] = None
  private var _eventLogCodec: Option[String] = None
  private var _listenerBus: LiveListenerBus = _
  private var _env: SparkEnv = _
  private var _statusTracker: SparkStatusTracker = _
  private var _progressBar: Option[ConsoleProgressBar] = None
  private var _ui: Option[SparkUI] = None
  private var _hadoopConfiguration: Configuration = _
  private var _executorMemory: Int = _
  private var _schedulerBackend: SchedulerBackend = _
  private var _taskScheduler: TaskScheduler = _
  private var _heartbeatReceiver: RpcEndpointRef = _
  @volatile private var _dagScheduler: DAGScheduler = _
  private var _applicationId: String = _
  private var _applicationAttemptId: Option[String] = None
  private var _eventLogger: Option[EventLoggingListener] = None
  private var _driverLogger: Option[DriverLogger] = None
  private var _executorAllocationManager: Option[ExecutorAllocationManager] = None
  private var _cleaner: Option[ContextCleaner] = None
  private var _listenerBusStarted: Boolean = false
  private var _jars: Seq[String] = _
  private var _files: Seq[String] = _
  private var _archives: Seq[String] = _
  private var _shutdownHookRef: AnyRef = _
  private var _statusStore: AppStatusStore = _
  private var _heartbeater: Heartbeater = _
  private var _resources: immutable.Map[String, ResourceInformation] = _
  private var _shuffleDriverComponents: ShuffleDriverComponents = _
  private var _plugins: Option[PluginContainer] = None
  private var _resourceProfileManager: ResourceProfileManager = _

LiveListenerBus

SparkEnv

SparkStatusTracker

ConsoleProgressBar

Configuration

SchedulerBackend

TaskScheduler

RpcEndpointRef

DAGScheduler

EventLoggingListener

DriverLogger

ExecutorAllocationManager

ContextCleaner

AppStatusStore

Heartbeater

ResourceInformation

ShuffleDriverComponents

PluginContainer

ResourceProfileManager