High Performance Computing Networking

Networks for MPI

It seems like we’ve gotten a rash of “how do I setup my new cluster for MPI?” questions on the Open MPI mailing list recently. I take this as a Very Good Thing, actually — it means more and more people are tinkering with and discovering the power of parallel computing, HPC, and MPI.

First public tools for the MPI_T interface in MPI-3.0

Today’s guest post is written by Tanzima Islam, Post Doctoral Researcher at Lawrence Livermore Laboratory, and Kathryn Mohror and Martin Schulz, Computer Scientists at Lawrence Livermore Laboratory. The latest version of the MPI Standard, MPI 3.0, includes a new interface for tools: the MPI Tools Information Interface, or “MPI_T”. MPI_T complements the existing MPI profiling […]

Can I MPI_SEND (and MPI_RECV) with a count larger than 2 billion?

This question is inspired by the fact that the “count” parameter to MPI_SEND and MPI_RECV (and friends) is an “int” in C, which is typically a signed 4-byte integer, meaning that its largest positive value is 231, or about 2 billion. However, this is the wrong question. The right question is: can MPI send and […]

MPI over 40Gb Ethernet

Half-round-trip ping-pong latency may be the first metric that everyone looks at with MPI in HPC, but bandwidth is one of the next metrics examined. 40Gbps Ethernet has been available for switch-to-switch links for quite a while, and 40Gbps NICs are starting to make their way down to the host. How does MPI perform with […]

Java Bindings for Open MPI

Today’s guest blog post is from Oscar Vega-Gisbert and Dr. Jose Roman from the Department of Information Systems and Computing at the Universitat Politècnica de València, Spain. We provide an overview of how to use the Java bindings included in Open MPI. The aim is to expose MPI functionality to Java programmers with minimal performance […]

Belated April Fool’s blog post

I was on vacation last week, and had a nice April Fool’s blog post queued up to be posted at 8am US Eastern time on 1 April 2014. It should have appeared whilst I was relaxing on a beach… but due to a bug in our WordPress installation, it didn’t.  And I didn’t find out […]

EuroMPI/ASIA 2014: Call for Workshop papers

Held in conjunction with EuroMPI/ASIA 2014 (see the associated call for papers), September 9-12, 2014.  In-cooperation status with ACM and SIGHPC. This year, EuroMPI/ASIA 2014 will hold two workshops.  Accepted workshop papers will be included in ACM’s ICPS conference proceedings of the EuroMPI/ASIA 2014. Workshop information is available on the EuroMPI/ASIA 2014 web site, and […]

Open MPI 1.7.5 released

After a metric ton of work by the entire community, Open MPI has released version 1.7.5. Among the zillions of minor updates and new enhancements are two major new features: MPI-3.0 conformance OpenSHMEM support (Linux only) See this post on the Open MPI announcement list for more details.

HPC in L3

As an HPC old-timer, I’m used to thinking of HPC networks as large layer-2 (L2) subnets.  All HPC traffic (e.g., MPI traffic) is therefore designed to stay within a single L2 subnet. The next layer up — L3 — is the “networking” layer in the OSI network model; it adds more abstractions than are available […]