Driver容错安全性是什么

发布时间：2021-12-16 15:28:12 作者：iii
来源：亿速云阅读：172

本篇内容主要讲解“Driver容错安全性是什么”，感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷，实用性强。下面就让小编来带大家学习“Driver容错安全性是什么”吧!

从数据层面，ReceivedBlockTracker为整个Spark Streaming应用程序记录元数据信息。

从调度层面，DStreamGraph和JobGenerator是Spark Streaming调度的核心，记录当前调度到哪一进度，和业务有关。

ReceivedBlockTracker在接收到元数据信息后调用addBlock方法，先写入磁盘中，然后在写入内存中。

Driver容错安全性是什么

根据batchTime分配属于当前BatchDuration要处理的数据到timToAllocatedBlocks数据结构中。

Driver容错安全性是什么

Time类的是一个case class，记录时间，重载了操作符，隐式转换，值得借鉴。

case class Time(private val millis: Long) {
  def milliseconds: Long = millis
  def < (that: Time): Boolean = (this.millis < that.millis)
  def <= (that: Time): Boolean = (this.millis <= that.millis)
  def > (that: Time): Boolean = (this.millis > that.millis)
  def >= (that: Time): Boolean = (this.millis >= that.millis)
  def + (that: Duration): Time = new Time(millis + that.milliseconds)
  def - (that: Time): Duration = new Duration(millis - that.millis)
  def - (that: Duration): Time = new Time(millis - that.milliseconds)
  // Java-friendlier versions of the above.
  def less(that: Time): Boolean = this < that
  def lessEq(that: Time): Boolean = this <= that
  def greater(that: Time): Boolean = this > that
  def greaterEq(that: Time): Boolean = this >= that
  def plus(that: Duration): Time = this + that
  def minus(that: Time): Duration = this - that
  def minus(that: Duration): Time = this - that
  def floor(that: Duration): Time = {
    val t = that.milliseconds
    new Time((this.millis / t) * t)
  }
  def floor(that: Duration, zeroTime: Time): Time = {
    val t = that.milliseconds
    new Time(((this.millis - zeroTime.milliseconds) / t) * t + zeroTime.milliseconds)
  }
  def isMultipleOf(that: Duration): Boolean =
    (this.millis % that.milliseconds == 0)
  def min(that: Time): Time = if (this < that) this else that
  def max(that: Time): Time = if (this > that) this else that
  def until(that: Time, interval: Duration): Seq[Time] = {
    (this.milliseconds) until (that.milliseconds) by (interval.milliseconds) map (new Time(_))
  }
  def to(that: Time, interval: Duration): Seq[Time] = {
    (this.milliseconds) to (that.milliseconds) by (interval.milliseconds) map (new Time(_))
  }
  override def toString: String = (millis.toString + " ms")
}
object Time {
  implicit val ordering = Ordering.by((time: Time) => time.millis)
}