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 papers I read all mentioned different OSes, or at least specialized hardware. Can this level of synchronization be achieved in Linux on commodity hardware? I imagine NTP doesn't have the resolution needed for this, and Don Becker has some strong feelings against NTP. I've tried googling on my own, but everything I come up with references NTP, or just the papers I've already read. -- Prentice _______________________________________________ Beowulf mailing list, [email protected] To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
