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From John Lilley <john.lil...@redpoint.net>
Subject RE: Task status query
Date Sat, 21 Sep 2013 13:52:44 GMT
Thanks Harsh!  The data-transport format is pretty easy, but how is the RPC typically set up?
 Does the AM open a listen port to accept the RPC from the tasks, and then pass the port/URI
to the tasks when they are spawned as command-line or environment?

-----Original Message-----
From: Harsh J [mailto:harsh@cloudera.com] 
Sent: Friday, September 20, 2013 7:47 AM
To: <user@hadoop.apache.org>
Subject: Re: Task status query

Right now its MR specific (TaskUmbilicalProtocol) - YARN doesn't have any reusable items here
yet, but there are easy to use RPC libs such as Avro and Thrift out there that make it easy
to do such things once you define what you want in a schema/spec form.

On Fri, Sep 20, 2013 at 5:32 PM, John Lilley <john.lilley@redpoint.net> wrote:
> Thanks Harsh.  Is this protocol something that is available to all AMs/tasks?  Or is
it up to each AM/task pair to develop their own protocol?
> john
> -----Original Message-----
> From: Harsh J [mailto:harsh@cloudera.com]
> Sent: Thursday, September 19, 2013 9:20 PM
> To: <user@hadoop.apache.org>
> Subject: Re: Task status query
> Hi John,
> YARN tasks can be more than simple executables. In case of MR, for example, tasks talk
to the AM and report their individual progress and counters back to it, via a specific protocol
(over the network), giving the AM more data to compute an near-accurate global progress.
> On Fri, Sep 20, 2013 at 12:18 AM, John Lilley <john.lilley@redpoint.net> wrote:
>> How does a YARN application master typically query ongoing status 
>> (like percentage completion) of its tasks?
>> I would like to be able to ultimately relay information to the user like:
>> 100 tasks are scheduled
>> 10 tasks are complete
>> 4 tasks are running and they are (4%, 10%, 50%, 70%) complete
>> But, given that YARN tasks are simply executables, how can the AM 
>> even get at this information?  Can the AM get access to stdout/stderr?
>> Thanks
>> John
> --
> Harsh J

Harsh J

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