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MapReduce >> mail # user >> Re: Reduce task hang[EMERGENCE]


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Re: Reduce task hang[EMERGENCE]
actuall these are all logs in the stderr, and stdout is empty
On Fri, Jan 3, 2014 at 4:12 PM, Azuryy Yu <[EMAIL PROTECTED]> wrote:

> Hi Harsh,
> There is only three warnnings in stderr
>
> *stderr logs*
>
> log4j:WARN No appenders could be found for logger (org.apache.hadoop.mapred.Child).
> log4j:WARN Please initialize the log4j system properly.
> log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
>
>
>
>
> On Fri, Jan 3, 2014 at 1:59 PM, Harsh J <[EMAIL PROTECTED]> wrote:
>
>> Hi again,
>>
>> I did not mention the TaskTracker log, but the actual Task JVM's
>> syslog/stderr/stdout. Do those log *any* problems at all?
>>
>> On Fri, Jan 3, 2014 at 11:16 AM, Azuryy Yu <[EMAIL PROTECTED]> wrote:
>> > Hi Harsh,
>> > Thanks.
>> >
>> > There is no any error logs for attempt_201312201200_34795_r_000000_0 in
>> the
>> > tasktracker log. only '0.0% reduce > copy >'
>> >
>> > I configured all hosts in all slaves and master.
>> >
>> > This job has only one reduce. it hanged. but I configured everybody's
>> max
>> > job running to '1' in the Fair scheduler file.
>> >
>> > but some people's max job running greater than one. and these people's
>> job
>> > never hanged...
>> >
>> >
>> > On Fri, Jan 3, 2014 at 1:13 PM, Harsh J <[EMAIL PROTECTED]> wrote:
>> >>
>> >> Does the Reduce task log (of attempt_201312201200_34795_r_000000_0)
>> >> show any errors in trying to communicate with the various TaskTrackers
>> >> in trying to obtain the data?
>> >>
>> >> On Fri, Jan 3, 2014 at 9:54 AM, Azuryy Yu <[EMAIL PROTECTED]> wrote:
>> >> > Add addtional:
>> >> >
>> >> > Our MR version is 1.2.1, not 1.0.4
>> >> >
>> >> > There is no useful information in the JT log.
>> >> >
>> >> >
>> >> > On Fri, Jan 3, 2014 at 12:20 PM, Azuryy Yu <[EMAIL PROTECTED]>
>> wrote:
>> >> >>
>> >> >> Hi,
>> >> >>
>> >> >> Our prod cluster met some issues recently,
>> >> >> All map tasks finished successfully, but reduce task hanged.
>> >> >>
>> >> >> but It's not happened on all TaskTrackers, only sometimes. we used
>> >> >> mapred-1.0.4
>> >> >>
>> >> >> There is "0.0% reduce > copy >" forever until kill task manually.
>> >> >>
>> >> >> reduce logs on the TaskTracker:
>> >> >> hadoop-hadoop-tasktracker-10-200-91-186.out:14/01/03 06:13:57 INFO
>> >> >> mapred.TaskTracker: JVM with ID: jvm_201312201200_34795_r_-365330778
>> >> >> given
>> >> >> task: attempt_201312201200_34795_r_000000_0
>> >> >> hadoop-hadoop-tasktracker-10-200-91-186.out:14/01/03 06:14:04 INFO
>> >> >> mapred.TaskTracker: attempt_201312201200_34795_r_000000_0 0.0%
>> reduce >
>> >> >> copy
>> >> >> >
>> >> >> hadoop-hadoop-tasktracker-10-200-91-186.out:14/01/03 06:14:08 INFO
>> >> >> mapred.TaskTracker: attempt_201312201200_34795_r_000000_0 0.0%
>> reduce >
>> >> >> copy
>> >> >> >
>> >> >> hadoop-hadoop-tasktracker-10-200-91-186.out:14/01/03 06:14:14 INFO
>> >> >> mapred.TaskTracker: attempt_201312201200_34795_r_000000_0 0.0%
>> reduce >
>> >> >> copy
>> >> >> >
>> >> >> hadoop-hadoop-tasktracker-10-200-91-186.out:14/01/03 06:14:17 INFO
>> >> >> mapred.TaskTracker: attempt_201312201200_34795_r_000000_0 0.0%
>> reduce >
>> >> >> copy
>> >> >> >
>> >> >> hadoop-hadoop-tasktracker-10-200-91-186.out:14/01/03 06:14:23 INFO
>> >> >> mapred.TaskTracker: attempt_201312201200_34795_r_000000_0 0.0%
>> reduce >
>> >> >> copy
>> >> >> >
>> >> >
>> >> >
>> >>
>> >>
>> >>
>> >> --
>> >> Harsh J
>> >
>> >
>>
>>
>>
>> --
>> Harsh J
>>
>
>