[Beowulf] PMIX and Julia?

[Chris Samuel]

On Monday, 19 November 2018 6:35:56 AM AEDT John Hearns via Beowulf wrote:

> What I am really asking is will pmix be totally necessary when running on
> near-exascale systems, or am I missing something? My thoughts are should
> the Julia world be looking at mpix adaptations? If someone with a clue
> about pmix could enlighten me I would be grateful.

My (limited) understanding of this is that PMI* is an MPI wire-up protocol, in 
other words a mechanism for the MPI ranks to discover each other, set up 
communications and also talk to the resource scheduler (if present).

There's a handy little description of PMI (v2 in this case) here:

https://wiki.mpich.org/mpich/index.php/PMI_v2_API

The PMIx website (along with standards documents etc) here:

https://pmix.org/

My instinct is that it might be better for Julia to sit on MPI and let it 
handle this for it, rather than have to know about PMI2/PMIx itself..

All the best!
Chris
-- 
 Chris Samuel  :  http://www.csamuel.org/  :  Melbourne, VIC