Spark源码分析之ResultTask处理

最新推荐文章于 2024-01-29 15:27:28 发布

thinktothings

最新推荐文章于 2024-01-29 15:27:28 发布

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分类专栏： Spark 文章标签： Spark源码分析之ResultTask处理

本文链接：https://blog.youkuaiyun.com/thinktothings/article/details/84898468

Spark源码分析之ResultTask处理

视频

Spark 源码分析之ResultTask原理分析图解(bilibili视频):https://www.bilibili.com/video/av37442139/?p=24
Spark 源码分析之ResultTask处理(bilibili视频):https://www.bilibili.com/video/av37442139/?p=25
Spark 源码分析之ResultTask原理分析图解(youtube视频):https://youtu.be/8LwOIfxjNqU
Spark 源码分析之ResultTask处理(youtube视频):https://youtu.be/1r7hzIXO11Y

width="800" height="500" src="//player.bilibili.com/player.html?aid=37442139&cid=66008946&page=24" scrolling="no" border="0" allowfullscreen="true"> width="800" height="500" src="//player.bilibili.com/player.html?aid=37442139&cid=66008946&page=25" scrolling="no" border="0" allowfullscreen="true">

概述

ResultTask 执行当前分区的计算，首先从ShuffleMapTask拿到当前分区的数据，会从所有的ShuffleMapTask都拿一遍当前的分区数据，然后调用reduceByKey自定义的函数进行计算
最后合并所有的ResultTask输出结果，进行输出

图解

在这里插入图片描述

ResultTask.scala 类

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.spark.scheduler

import java.nio.ByteBuffer

import java.io._

import org.apache.spark._
import org.apache.spark.broadcast.Broadcast
import org.apache.spark.rdd.RDD

/**
 * A task that sends back the output to the driver application.
 *
 * See [[Task]] for more information.
 *
 * @param stageId id of the stage this task belongs to
 * @param taskBinary broadcasted version of the serialized