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 <[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? > > Thanks > > John > > -- Harsh J
