hadoop设置公平队列

http://hadoop.apache.org/docs/r1.2.1/fair_scheduler.html

fair-scheduler.xml文档

<?xml version="1.0"?>  
<allocations>  
  <pool name="test_pool">
    <minMaps>5</minMaps>
    <minReduces>5</minReduces>
    <maxMaps>15</maxMaps>
    <maxReduces>15</maxReduces>
    <minSharePreemptionTimeout>300</minSharePreemptionTimeout>
  </pool>
  <user name="app">
    <maxRunningJobs>5</maxRunningJobs>
  </user>
  <user name="ronnie.zhang">
    <maxRunningJobs>5</maxRunningJobs>
  </user>
  <user name="dean.wu">
    <maxRunningJobs>5</maxRunningJobs>
  </user>
  <userMaxJobsDefault>3</userMaxJobsDefault>
  <fairSharePreemptionTimeout>600</fairSharePreemptionTimeout>
</allocations>

　　mapred-site.xml文档中添加

   <property>
      <name>mapred.jobtracker.taskScheduler</name>
      <value>org.apache.hadoop.mapred.FairScheduler</value>
    </property>

默认使用FIFO队列。