topic The very basic distinction in Intel® MPI Library

Cluster vs. Fabric

octogone — Mon, 13 Jul 2015 19:22:56 GMT

Hello !

What is the difference between a cluster and a fabric? Is the network architecture the differentiating element?

Many thanks!

The very basic distinction

Gergana_S_Intel — Mon, 13 Jul 2015 23:39:11 GMT

The very basic distinction between the two is that the latter (fabric) is a component of the former (cluster). At a very high level, an HPC cluster is a set of homogeneous machines connected together through some high-speed interconnect. And even those definitions are now changing since the machines no longer have to be homogeneous - some might have coprocessor cards, others might not; they might be running different architectures, have different OS or resources available, etc.

When we say fabric, we usually refer to the software-level layer that MPI, for example, might use to communicate between the nodes. Underneath the fabric would be the low-level interconnect (e.g. ethernet, infiniband) and all its associated drivers.

So if you start at highest application level, you as a developer will be making calls to the MPI library, the MPI library would be interacting with the underlying fabric interface (e.g. for Intel MPI, you would select the 'dapl' fabric to run over the infiniband network), which will in turn do its own communication to the firmware that sits on top of the network cards.

I hope this helped a bit :) Let me know if you have further questions.

Regards,
~Gergana

what dose MPI & HPC starnd

winura_w_ — Tue, 14 Jul 2015 14:59:05 GMT

what dose MPI & HPC starnd for?

MPI is the Message Passing

Gergana_S_Intel — Tue, 14 Jul 2015 19:05:44 GMT

MPI is the Message Passing Interface - a set of library routines that allows explicit communication between independent nodes.

HPC is High Performance Computing - a field of technology using supercomputers to solve compute-intensive scientific and engineering problems.

~Gergana