api

Contents

1. 1. api.java
   1. 1.1. JavaDoubleRDD
2. 2. broadcast
   1. 2.1. TorrentBroadcast
3. 3. deploy
4. 4. rdd
   1. 4.1. CoalescedRDD
      1. 4.1.1. DefaultPartitionCoalescer

api.java

该包用于java编程时

JavaDoubleRDD

将scala Double 转java Double

注意一行代码：import java.lang.{Double => JDouble}
scala语法起了个类的别名

而java也有类似的，如import com.example.Calendar as MyCalendar

broadcast

keep a read-only variable cached on each machine rather than tasks

TorrentBroadcast

driver将广播对象切成small chunks
避免driver单点分发成为瓶颈，executor从driver的BlockManager取到数据后可以供其他executor获取

deploy

提交任务

rdd

CoalescedRDD

DefaultPartitionCoalescer

locality information