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MPI Ping-Pong: Latency - Warnings RRS feed

  • Question

  • We are experiencing some issues with HPC jobs failing with loss of connection to nodes.  In the process of running diagnostics we are seeing nodes with MPI Ping-Pong Latency warnings.  I suspect that there is something going on with the network connectivity based on these issues but I don't know where to start looking.

    So... can somebody explain to me exactly what a MPI Ping-Pong: Latency warning is.  And what can I do to help eliminate the latency issues.

    Thanks!

        Eric Sten

    Monday, April 21, 2014 1:40 PM

All replies

  • MPI Ping-Pong is designed to test the latency in a HPC cluster with IB network.

    What value did you see in the test result?

    In a non-IB network environment, the value can be around 500 and a warning will be raised.

    Note the measurement unit is usecs, which equals 1/1000 ms.

    Wednesday, April 23, 2014 7:59 AM