I would like to know if it is possible that the only
protocol used among MPI
running applications could be UDP.
I wonder if lamd daemons interchange MPI messages using UDP.
We are working in a interconnection network simulator for
MPP (massive
parallel processors), and we are testing our simulator with
real traffic
coming from MPI applications simulated in a Simics full
platform simulator.
At the moment we are using MPICH but we have discovered that
the TCP
congestion control distorts our results. This is because our
network does
not lose any message, but if it is very congested then TCP
thinks that the
message has lost and retransmits it, and the transmision
window goes to 1,
(TCP slow-start mechanism) which turns the whole simulation
very slow.
For the hosts communicating we use RedHat 7.3 with the
2.4.18 kernel. Does
LAM support it?
Thank you very much,
----------------------------------------
Francisco Javier Ridruejo Pérez
Red Académica i2BASK (UPV/EHU)
Parque Tecnológico de San Sebastián
Pº Mikeletegi, 69 - Torre Arbide Norte
20009 Donostia - San Sebastián
Tel.: +34 943 018 705
Fax.: +34 943 015 590
E-mail: franciscojavier.ridruejo ehu.es
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