Understanding fair schedulers

[praveenesh kumar]

Understanding Fair Schedulers better.

Can we create mulitple pools in Fair Schedulers. I guess Yes. Please
correct me.

Suppose I have 2 pools in my fair-scheduler.xml

1. Hadoop-users : Min map : 10, Max map : 50, Min Reduce : 10, Max Reduce :
50
2. Admin-users: Min map : 20, Max map : 80, Min Reduce : 20, Max Reduce : 80

I have 5 users, who will be using these pools. How will I allocate specific
pools to specific users ?

Suppose I want user1,user2 to use "Hadoop-users" pool and user3,user4,user5
to use "Admin users"

In http://hadoop.apache.org/common/docs/r0.20.205.0/fair_scheduler.html
they have mentioned allocations something like this.

<?xml version="1.0"?>
<allocations>
  <pool name="sample_pool">
    <minMaps>5</minMaps>
    <minReduces>5</minReduces>
    <maxMaps>25</maxMaps>
    <maxReduces>25</maxReduces>
    <minSharePreemptionTimeout>300</minSharePreemptionTimeout>
  </pool>
  <user name="sample_user">
    <maxRunningJobs>6</maxRunningJobs>
  </user>
  <userMaxJobsDefault>3</userMaxJobsDefault>
  <fairSharePreemptionTimeout>600</fairSharePreemptionTimeout>
</allocations>

I tried creating more pools, its happening, but how to allocate users to
use specific pools ?

Thanks,
Praveenesh