FairScheduler in hadoop mapreduce

as i reviewed the book,it saied:

a.it 's goal is to let each user fairly share the cluster resources

b.jobs are placed in pools ,and each user has their own pool .

c.u can set the priorify of a pool ,so

d.this Scheduler supports preemption

 

first ,i thought,if i run a client to submit two SEQUENCE jobs,if i use FAIR sheduler,

1.whether the results will be out of order as the jobs are Faired?

2.sinc they are faired,so whether it wil be lead to definite-loop as it faire resources fluently?(for example,one of our national policys is "一部分人先富起来,最終实现共同富裕".