stack trace from hung task

[Sriram Rao <sr...@gmail.com>]

Hi,

When a task tracker kills a non-responsive task, it prints out a
message "Task XXXXX not reported status for 600 seconds. Killing!".
The stack trace it then dumps out is that of the task tracker itself.
Is there a way to get the hung task to dump out its stack trace before
exiting?  Would be nice if there was an easy way to send a kill -3 to
the hung process and then kill it.

Sriram

Re: stack trace from hung task

[Jason Venner <ja...@attributor.com>]

We provided a patch for 16 that could be retrofitted into 19

Our internal use of this has shown that jstack can hang in some 
situations, and that just sending the sigquit is safer.

https://issues.apache.org/jira/browse/HADOOP-3994

Ryan LeCompte wrote:
> For what it's worth, I started seeing these when I upgraded to 0.19. I
> was using 10 reduces, but changed it to 30 reduces for my job and now
> I don't see these errors any more.
>
> Thanks,
> Ryan
>
>
> On Fri, Dec 5, 2008 at 2:44 PM, Sriram Rao <sr...@gmail.com> wrote:
>   
>> Hi,
>>
>> When a task tracker kills a non-responsive task, it prints out a
>> message "Task XXXXX not reported status for 600 seconds. Killing!".
>> The stack trace it then dumps out is that of the task tracker itself.
>> Is there a way to get the hung task to dump out its stack trace before
>> exiting?  Would be nice if there was an easy way to send a kill -3 to
>> the hung process and then kill it.
>>
>> Sriram
>>
>>     

Re: stack trace from hung task

[Ryan LeCompte <le...@gmail.com>]

For what it's worth, I started seeing these when I upgraded to 0.19. I
was using 10 reduces, but changed it to 30 reduces for my job and now
I don't see these errors any more.

Thanks,
Ryan


On Fri, Dec 5, 2008 at 2:44 PM, Sriram Rao <sr...@gmail.com> wrote:
> Hi,
>
> When a task tracker kills a non-responsive task, it prints out a
> message "Task XXXXX not reported status for 600 seconds. Killing!".
> The stack trace it then dumps out is that of the task tracker itself.
> Is there a way to get the hung task to dump out its stack trace before
> exiting?  Would be nice if there was an easy way to send a kill -3 to
> the hung process and then kill it.
>
> Sriram
>