scala – 如何获取当前作业中使用的核心数？

>选项1：Spark web ui为我提供有关总核心和已用核心的信息.

>选项2：默认值：

sc.defaultParallelism通常设置为群集中的工作核心数
>选项3：可以像下面这样使用ExectorInfo.totalCores并尝试……它应该可以工作.

docs说

public class ExecutorInfo extends Object
Stores information about an
executor to pass from the scheduler to SparkListeners.

import org.apache.spark.scheduler.{SparkListener,SparkListenerExecutorAdded}

/**
  * Logs info of added executors.
  */
final class ExecutorLogger extends SparkListener {

  override def onExecutorAdded(executorAdded: SparkListenerExecutorAdded): Unit =
    println(s"rExecutor ${executorAdded.executorId} added: ${executorAdded.executorInfo.executorHost} ${executorAdded.executorInfo.totalCores} cores")

}