[Beowulf] software for activating one of many programs but not the others?

[David Mathog]

On 2019-08-20 16:19, Steven Taylor wrote:
> I like the idea of environment modules (or refresh). What's the 
> downside?

For modules?  Not much really...

Time spent writing modules from scratch if one of the automated systems 
isn't used.

In a really complex environment I suppose it might be possible to hit 
the
environment block size limit (sum of all variable lengths) of 32767 
characters.
With Lmod itself and 3 modules loaded:

   set | wc

is 5183.  So there is still a lot of space left.  (Yes, that is only an 
approximate measure of usage inside the block.)

PATH related issues might be a PITA to diagnose with 20 or 30 
directories on the
included.  (Lmod, as far as I can tell, offers no protection against 
name collisions in included packages.)

My bigger gripe is with the "portability" solutions which are the 
equivalent of defining yet another operating system environment and then 
building within it. That is another variation on this theme:

   https://xkcd.com/927/

Regards,

David Mathog
mathog at caltech.edu
Manager, Sequence Analysis Facility, Biology Division, Caltech