[MapReduce-user] Is there a way to see what file killed a mapper?

Someone might have a more graceful method of determining this but I've
found outputting that kind of data to counters is the most effective
way. Otherwise you could use stderr or stdout but then you would need to
mine the log data on each node to figure it out.



Matt



From: Jonathan Coveney
Sent: Tuesday, May 10, 2011 10:36 AM
To: [email protected]
Subject: Is there a way to see what file killed a mapper?



I have a basic job that is dying, I think, on one badly compressed file.
Is there a way to see what file it is choking on? Via the job tracker I
can find the mapper that is dying but I cannot find a record of the file
that it died on.



Thank you for your help

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MapReduce updates the task's configuration and sets 'map.input.file' to point to the file on which the task intends to work on. In the new MapReduce API, its renamed to 'mapreduce.map.input.file'. You can print the value corresponding to 'map.input.file'. Similarly 'map.input.start' point to the start offset in the input file while 'map.input.length' points to the total size of the data to be read.
Amar


On 5/10/11 9:05 PM, "Jonathan Coveney" wrote:

I have a basic job that is dying, I think, on one badly compressed file. Is there a way to see what file it is choking on? Via the job tracker I can find the mapper that is dying but I cannot find a record of the file that it died on.

Thank you for your help

Thanks, these are quite useful.

2011/5/10 Amar Kamat <[email protected]>