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 <[EMAIL PROTECTED]> 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?