How to ensure that only one worker runs per node

[Matthew Saltz <sa...@gmail.com>]

Hi everyone,

Is there a good way (a configuration I'm guessing) to prevent more than one
worker from running per node? I saw in this thread
<https://www.mail-archive.com/user@giraph.apache.org/msg01580.html> to use
mapred.tasktracker.map.tasks.maximum=1, but that doesn't seem to be
working. Thanks for the help.

Best,
Matthew

Re: How to ensure that only one worker runs per node

[Matthew Saltz <sa...@gmail.com>]

Thanks Matthew. I just realized in searching a bit more that the variable
has to be set in the mapred-site.xml configuration file with hadoop
0.20.203, otherwise it doesn't affect anything. I was setting it in the
command line.  I've already been setting the number of workers the way you
suggested. I'll give it a try.

Best,
Matthew

On Thu, Oct 30, 2014 at 12:36 PM, Matthew Cornell <ma...@matthewcornell.org>
wrote:

> As I understand it, 1) set the variable to 1 as you say, and 2)
> specify the number of workers to the number of nodes - 1 (for the
> master). When you run a job you can look at the 'map' link on the
> tasktracker ui to see all the workers plus master.
>
> On Thu, Oct 30, 2014 at 7:11 AM, Matthew Saltz <sa...@gmail.com> wrote:
> > Hi everyone,
> >
> > Is there a good way (a configuration I'm guessing) to prevent more than
> one
> > worker from running per node? I saw in this thread to use
> > mapred.tasktracker.map.tasks.maximum=1, but that doesn't seem to be
> working.
> > Thanks for the help.
> >
> > Best,
> > Matthew
> >
>
>
>
> --
> Matthew Cornell | matt@matthewcornell.org | 413-626-3621 | 34
> Dickinson Street, Amherst MA 01002 | matthewcornell.org
>

Re: How to ensure that only one worker runs per node

[Matthew Cornell <ma...@matthewcornell.org>]

As I understand it, 1) set the variable to 1 as you say, and 2)
specify the number of workers to the number of nodes - 1 (for the
master). When you run a job you can look at the 'map' link on the
tasktracker ui to see all the workers plus master.

On Thu, Oct 30, 2014 at 7:11 AM, Matthew Saltz <sa...@gmail.com> wrote:
> Hi everyone,
>
> Is there a good way (a configuration I'm guessing) to prevent more than one
> worker from running per node? I saw in this thread to use
> mapred.tasktracker.map.tasks.maximum=1, but that doesn't seem to be working.
> Thanks for the help.
>
> Best,
> Matthew
>



-- 
Matthew Cornell | matt@matthewcornell.org | 413-626-3621 | 34
Dickinson Street, Amherst MA 01002 | matthewcornell.org