[MAPREDUCE-4765] Restarting the JobTracker programmatically can cause DelegationTokenRenewal to throw an exception

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.1.0
• Fix Version/s: 1.2.0
• Component/s: jobtracker, mrv1
• Hadoop Flags: Reviewed
• Assignee: Robert Kanter
• Reporter: Robert Kanter
• Created: 01/Nov/12 19:43
• Updated: 15/May/13 05:15
• Resolved: 07/Nov/12 21:13

Description

The DelegationTokenRenewal class has a global Timer; when you stop the JobTracker by calling stopTracker() on it (or stopJobTracker() in MiniMRCluster), the JobTracker will call close() on DelegationTokenRenewal, which cancels the Timer. If you then start up the JobTracker again by calling startTracker() on it (or startJobTracker() in MiniMRCluster), the Timer won't necessarily be re-created; and DelegationTokenRenewal will later throw an exception when it tries to use the Timer again (because you can't reuse a canceled Timer).

DelegationTokenRenewal doesn't seem to be used in trunk, so we only need this for branch-1