Hi ,All, I encountered a problem in using Cloudera Hadoop 0.20.2-cdh3u1. When I use the fair Scheduler I find the scheduler seems not support preemption. Can anybody tell me whether preemption is supported in this version? This is my configration: mapred-site.xml <property> <name>mapred.jobtracker.taskScheduler</name> <value>org.apache.hadoop.mapred.FairScheduler</value> </property> <property> <name>mapred.fairscheduler.allocation.file</name> <value>/usr/lib/hadoop-0.20/conf/fair-scheduler.xml</value> </property> <property> <name>mapred.fairscheduler.preemption</name> <value>true</value> </property> <property> <name>mapred.fairscheduler.preemption.only.log</name> <value>true</value> </property> <property> <name>mapred.fairscheduler.preemption.interval</name> <value>15000</value> </property> <property> <name>mapred.fairscheduler.weightadjuster</name> <value>org.apache.hadoop.mapred.NewJobWeightBooster</value> </property> <property> <name>mapred.fairscheduler.sizebasedweight</name> <value>true</value> </property> fair-scheduler.xml <allocations> <pool name="root"> <minMaps>10</minMaps> <minReduces>5</minReduces> <maxMaps>200</maxMaps> <maxReduces>80</maxReduces> <maxRunningJobs>100</maxRunningJobs> <minSharePreemptionTimeout>30</minSharePreemptionTimeout> <weight>1.0</weight> </pool> <pool name="hadoop"> <minMaps>10</minMaps> <minReduces>5</minReduces> <maxMaps>80</maxMaps> <maxReduces>80</maxReduces> <maxRunningJobs>5</maxRunningJobs> <minSharePreemptionTimeout>30</minSharePreemptionTimeout> <weight>1.0</weight> </pool> <user name="user1"> <maxRunningJobs>10</maxRunningJobs> </user> <poolMaxJobsDefault>20</poolMaxJobsDefault> <userMaxJobsDefault>10</userMaxJobsDefault> <defaultMinSharePreemptionTimeout>30</defaultMinSharePreemptionTimeout> <fairSharePreemptionTimeout>30</fairSharePreemptionTimeout> </allocations>
regards, 2012-03-07 hao.wang