-Re: Long running Join Query - Reduce task fails due to failing to report status
It is not clear from your post but your job is always failing during the
same step? Or only sometimes? Or only once?
Since it's a hive query I would modify it to find the root cause.
First create temporary "files" which are the results from the three first
Then run the fourth M/R on it and try to filter the data in order to see if
it is related to the volume or the format.
On Fri, Aug 24, 2012 at 7:44 PM, Igor Tatarinov <[EMAIL PROTECTED]> wrote:
> Why don't you try splitting the big query into smaller ones?
> On Fri, Aug 24, 2012 at 10:20 AM, Tim Havens <[EMAIL PROTECTED]> wrote:
>> Just curious if you've tried using Hive's explain method to see what IT
>> thinks of your query.
>> On Fri, Aug 24, 2012 at 9:36 AM, Himanish Kushary <[EMAIL PROTECTED]>wrote:
>>> We have a complex query that involves several left outer joins resulting
>>> in 8 M/R jobs in Hive.During execution of one of the stages ( after three
>>> M/R has run) the M/R job fails due to few Reduce tasks failing due to
>>> Most of the reduce tasks go through fine ( within 3 mins) but the last
>>> one gets stuck for a long time (> 1 hour) and finally after several
>>> attempts gets killed due to "failed to report status for 600 seconds.
>>> What may be causing this issue ? Would hive.script.auto.progress help in
>>> this case ? As we are not able to get much information from the log files
>>> how may we approach resolving this ? Will tweaking of any specific M/R
>>> parameters help ?
>>> The task attempt log shows several lines like this before exiting :
>>> 2012-08-23 19:17:23,848 INFO ExecReducer: ExecReducer: processing 219000000 rows: used memory = 408582240
>>> 2012-08-23 19:17:30,189 INFO ExecReducer: ExecReducer: processing 220000000 rows: used memory = 346110400
>>> 2012-08-23 19:17:37,510 INFO ExecReducer: ExecReducer: processing 221000000 rows: used memory = 583913576
>>> 2012-08-23 19:17:44,829 INFO ExecReducer: ExecReducer: processing 222000000 rows: used memory = 513071504
>>> 2012-08-23 19:17:47,923 INFO org.apache.hadoop.mapred.FileInputFormat: Total input paths to process : 1
>>> Here are the reduce task counters:
>>> *Map-Reduce Framework* Combine input records0 Combine output records0Reduce input groups
>>> 222,480,335 Reduce shuffle bytes7,726,141,897 Reduce input records
>>> 222,480,335 Reduce output records0 Spilled Records355,827,191 CPU time
>>> spent (ms)2,152,160 Physical memory (bytes) snapshot1,182,490,624Virtual memory (bytes) snapshot
>>> 1,694,531,584 Total committed heap usage (bytes)990,052,352
>>> The tasktracker log gives a thread dump at that time but no exception.
>>> *2012-08-23 20:05:49,319 INFO org.apache.hadoop.mapred.TaskTracker:
>>> Process Thread Dump: lost task*
>>> *69 active threads*
>>> Thanks & Regards
>> "The whole world is you. Yet you keep thinking there is something else."
>> - Xuefeng Yicun 822-902 A.D.
>> Tim R. Havens
>> Google Phone: 573.454.1232
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