5.How will the Fair Scheduler handle these two jobs?

You have a cluster running with the fair Scheduler enabled.
There are currently no jobs running on the cluster, and you submit a job A,
so that only job A is running on the cluster. A while later, you submit Job B.
Now Job A and Job B are running on the cluster at the same time. How will the Fair
Scheduler handle these two jobs?

A.When Job B gets submitted, it will get assigned tasks, while job A continues to run with fewer tasks.
B.When Job B gets submitted, Job A has to finish first, before job B can gets scheduled.
C.When Job A gets submitted, it doesn’t consumes all the task slots.
D.When Job A gets submitted, it consumes all the task slots.

问题:
       公平调度器对这两个jobs怎样处理？

解析: AD
       当只有一个job A在运行,这个job A会使用整个集群的 任务solts;
当另外一个job B被提交,那么任务solts会被释放分配给新的job B,
然而job A则会继续使用少些的任务solts,运行着。

详解Hadoop Slots的含义

http://www.07net01.com/2014/09/157715.html
http://net.pku.edu.cn/~course/cs402/2010/resource/2009/hadoop-0.20.0/docs/fair_scheduler.html