On Mon, Sep 29, 2008 at 01:10:49PM -0700, Prentice Bisbal wrote: > In the previous thread I instigated about running services in cluster > nodes, there was some mentioning of precisely synchronizing the system > clocks and this issue is also mentioned in this paper: > > "The Case of Missing Supercomputer Performance: Achieving Optimal > Performance on the 8,192 processor ASCI Q" (Petrini, Kerbisin and Pakin) > http://hpc.pnl.gov/people/fabrizio/papers/sc03_noise.pdf > > I've also read a few other papers on the topic, and it seems you need to > sync the system clocks to ~1 uS. On top of that, I imagine you also need > to synch the activities of each system so they all stop to do the same > system-level tasks at the same time.
The IEEE-1588 "Precision Time Protocol" can provide such levels of global clock synchronization. Shameless plug: See "Hardware Assisted Precision Time Protocol (PTP, IEEE-1588) - Design and Case Study" presented at the recent LCI conference; <http://www.linuxclustersinstitute.org/conferences/archive/2008/technicalpapers.html> -- David N. Lombard, Intel, Irvine, CA I do not speak for Intel Corporation; all comments are strictly my own. _______________________________________________ Beowulf mailing list, [email protected] To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
