On 29. aug. 2014, at 22.20, Michael Di Domenico wrote: > i believe all the pairs do pass through a spine.
IB is destination routed. Without knowing your topology and/or traffic pattern, I expect the pairs connected to the same leaf not to go though the spine. And given that is the case, you are vulnerable to the parking-lot problem > i'm not familiar > with the "parking-lot problem", i'll google it, but suspect a > bazillion hits will come back You will. But if there are no erroneous components in your system, the behavior of your system is a function of the system itself and the workload given to it. The parking-lot problem might be an explanation of less than perfect bnehaviour. Not saying it is though. Håkon > > >> Sendt fra min HTC >> >> ----- Reply message ----- >> Fra: "Michael Di Domenico" <mdidomeni...@gmail.com> >> Til: "Beowulf Mailing List" <Beowulf@beowulf.org> >> Emne: [Beowulf] mpi slow pairs >> Dato: fre., aug. 29, 2014 18:09 >> >> >> >> On Fri, Aug 29, 2014 at 11:38 AM, John Hearns <john.hea...@viglen.co.uk> >> wrote: >>>> Also have you run ibdiagnet to see if anything is flagged up? >>> >>> i've run a multitude of ib diags on the machines, but nothing is popping >>> out as wrong. what's weird is that it's only certain pairing of machines >>> not any one machine in general. >>> >>> Would that then be a problem in one of the blades or a part of the switch? >> >> not sure yet, i think on the spine modules in the switch is silently >> failing to send traffic a full speed, but i've not been able to >> "prove" this yet. >> _______________________________________________ >> Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing >> To change your subscription (digest mode or unsubscribe) visit >> http://www.beowulf.org/mailman/listinfo/beowulf > _______________________________________________ > Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing > To change your subscription (digest mode or unsubscribe) visit > http://www.beowulf.org/mailman/listinfo/beowulf _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
