the mapred job -kill command doesn't seem to fully clean up the application.
If you kill a job and run mapred job -list again it still shows up as running:
mapred job -kill job_1310072430717_0003
Killed job job_1310072430717_0003
mapred job -list
JobId State StartTime UserName Queue Priority SchedulingInfo
job_1310072430717_0003 RUNNING 0 tgraves default NORMAL 22.214.171.124:19888/yarn/job/job_1310072430717_3_3
Running kill again will error out.
It also still shows up in the RM Applications UI as running with a note of: Kill Job received from client
job_1310072430717_0003 Job received Kill while in RUNNING state.