Dirver Program(SparkConf) package org.apache.spark.SparkConf
Master package org.apache.spark.deploy.master
SparkContext package org.apache.spark.SparkContext
Stage package org.apache.spark.scheduler.Stage
Task package org.apache.spark.scheduler.Task
DAGScheduler package org.apache.spark.scheduler
TaskScheduler package org.apache.spark.scheduler.TaskScheduler
TaskSchedulerImpl package org.apache.spark.scheduler
Worker package org.apache.spark.deploy.worker
Executor package org.apache.spark.executor
BlockManager package org.apache.spark.storage
TaskSet package org.apache.spark.scheduler
//初始化后开始创建
// Create and start the scheduler
val (sched, ts) = SparkContext.createTaskScheduler(this, master)
_schedulerBackend = sched
_taskScheduler = ts
_dagScheduler = new DAGScheduler(this)
_heartbeatReceiver.send(TaskSchedulerIsSet)
/**
* Create a task scheduler based on a given master URL.
* Return a 2-tuple of the scheduler backend and the task scheduler.
*/
private def createTaskScheduler(
sc: SparkContext,
master: String): (SchedulerBackend, TaskScheduler) = {
master match {
case "local" =>
实例化一个
val scheduler = new TaskSchedulerImpl(sc)
构建masterUrls：
val masterUrls = localCluster.start()
据说是非常关键的backend：
val backend = new SparkDeploySchedulerBackend(scheduler, sc, masterUrls)
scheduler.initialize(backend)
backend.shutdownCallback = (backend: SparkDeploySchedulerBackend) => {
localCluster.stop()
}
(backend, scheduler)