(Inter)operability

Greg Astfalk (astfalk@hydra.rsn.hp.com)
Wed, 10 Jul 96 22:11:28 -0500

Wright Dave writes:
> Performance is always very important. However, support for files that
> can be read/written transparently on multiple architectures (described
> by Bill as option C) is also very important in a production environment.
> >From my experience, a suitable compromise is to have MPI-IO use high-
> performance, native binary files by default (option A). But, also enable
> MPI-IO to use portable (option C) binary files (possibly XDR) when
> requested by the application to support a heterogeneous production
> environment.

I had raised some issues about this in my previous email.

> An example where portable binary files is important is when the
> 'solver' runs on one architecture but the interactive post-processor(s)
> run on another (possibly desktop) architecture. Requiring off-line
> conversion is not necessarily the best option in this scenario.

This is the very same case I used at several meetings as the
protypical example of the need for interoperability. Conversion
(i.e., Bill's Option #A) isn't the best solution, but it is the
solution that is easiest from an implementation and a performance
perspective.