On Jan 1, 2014, at 6:30 PM, Jeff Hammond <[email protected]> wrote:

...

The only thing you can do is have mpiexec ssh to each node, and get the information needed. This is (1) not scalable, and (2) not viable unless we start distributing a program that gets the datatype information for all datatypes we care about and compare the bits inside mpiexec.

Can't you do this in a tree rather than root-to-all?

No. To do a tree, I need some proxy application that I need to run on the intermediate nodes, that will do the second-level ssh. This proxy application will need to be heterogeneous-safe if it needs to communicate with mpiexec. — Pavan -- Pavan Balaji http://www.mcs.anl.gov/~balaji