[MAPREDUCE-2157] safely handle InterruptedException and interrupted status in MR code

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Assignee: Joydeep Sen Sarma
• Reporter: Joydeep Sen Sarma
• Created: 26/Oct/10 17:50
• Updated: 10/Jul/12 21:27

Description

taskLauncher thread exits on interruptedException and on Interrupt conditions without checking for any shutdown flag:

while (!Thread.interrupted())

{ ... }

catch (InterruptedException e)

{ return; // ALL DONE }

}

If the interrupt happened because of reasons other than TaskTracker.close() - then the TaskTracker will look functional - but will not be able to schedule tasks anymore. worse - some tasks (that are in the launch queue) will hang indefinitely un UNASSIGNED state (the JobTracker will not even time them out). We have seen this cause jobs to hang indefinitely.

It seems that the interrupted condition can be set by log4j (of which there are many calls inside TaskLauncher). See or instance: http://logging.apache.org/log4j/1.2/xref/org/apache/log4j/AsyncAppender.html