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] = Noneprivate var _eventLogCodec: Option[String] = Noneprivate var _listenerBus: LiveListenerBus = _private var _env: SparkEnv = _private var _statusTracker: SparkStatusTracker = _private var _progressBar: Option[ConsoleProgressBar] = Noneprivate var _ui: Option[SparkUI] = Noneprivate 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] = Noneprivate var _eventLogger: Option[EventLoggingListener] = Noneprivate var _driverLogger: Option[DriverLogger] = Noneprivate var _executorAllocationManager: Option[ExecutorAllocationManager] = Noneprivate var _cleaner: Option[ContextCleaner] = Noneprivate var _listenerBusStarted: Boolean = falseprivate 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] = Noneprivate var _resourceProfileManager: ResourceProfileManager = _

LiveListenerBus

SparkEnv

SparkStatusTracker

ConsoleProgressBar

Configuration

SchedulerBackend

TaskScheduler

RpcEndpointRef

DAGScheduler

EventLoggingListener

DriverLogger

ExecutorAllocationManager

ContextCleaner

AppStatusStore

Heartbeater

ResourceInformation

ShuffleDriverComponents

PluginContainer

ResourceProfileManager