[GRASSLIST:5923] Re: Working with grass in clusteres enviroments.

[Markus Neteler]

On Fri, Mar 28, 2003 at 11:36:12PM +0100, Antonio G. - Geotronix wrote:
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> Hi.
> 
> I was wondering if, when and how Grass will ever support clustering.
> Now days, setting  up a openMosix cluster is cheap and easy, giving on
> the other hand pure computing power. As far as I can understand, the
> fact that Grass is a collection of unix programs that can run
> indipendently on the same machine makes Grass the optimum playground for
> testing mosix clusters.
> Do you know of any Grass-openmosix experiments on the net?

Not on the net, but I have done that recently.

> BTW. I had pointed out in previous months that some Grass apps would
> benefit enourmously from being parallized. I think of r.mapcalc,
> r.surf.contour, etc.
> Are there plans of parallelizing such apps?
No plans at time. Of course (new) developers are welcome to pick up
such task.

In general GRASS can only be run pseudo-parallel, i.e. multiple-sequentially
on an openMosix cluster. I have written a startup-script for launching
several GRASS sessions in parallel. My task was to reclass some hundred 
aerial images (i.smap). They were processed individually in multiple sessions.
The main trick is to run such multiple GRASS sessions in own mapsets
within the same location. Only then you can avoid problems that the
WIND file is not overwritten by concurring sessions.

If there is any interest in the launch script, I can make it available.

Markus Neteler