[EMAIL PROTECTED] wrote: > On Wed, 23 Jul 2008, Tharindu Rukshan Bamunuarachchi wrote: > > >> 10,000 x 700 = 7MB per second ...... >> >> We have this rate for whole day .... >> >> 10,000 orders per second is minimum requirments of modern day stock >> exchanges ... >> >> Cache still help us for ~1 hours, but after that who will help us ... >> >> We are using 2540 for current testing ... >> I have tried same with 6140, but no significant improvement ... only one or >> two hours ... >> > > It might not be exactly what you have in mind, but this "how do I get > latency down at all costs" thing reminded me of this old paper: > > http://www.sun.com/blueprints/1000/layout.pdf > > I'm not a storage architect, someone with more experience in the area care > to comment on this ? With huge disks as we have these days, the "wide > thin" idea has gone under a bit - but how to replace such setups with > modern arrays, if the workload is such that caches eventually must get > blown and you're down to spindle speed ? >
Bob Larson wrote that article, and I would love to ask him for an update. Unfortunately, he passed away a few years ago :-( http://blogs.sun.com/relling/entry/bob_larson_my_friend I think the model still holds true, the per-disk performance hasn't significantly changed since it was written. This particular problem screams for a queuing model. You don't really need to have a huge cache as long as you can de-stage efficiently. However, the original poster hasn't shared the read workload details... if you never read, it is a trivial problem to solve with a WOM. -- richard _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
