On Tue, Jan 15, 2013 at 11:00 AM, Dimitri Maziuk <dmaziuk@xxxxxxxxxxxxx> wrote: > On 01/15/2013 12:36 PM, Gregory Farnum wrote: >> On Tue, Jan 15, 2013 at 10:33 AM, Dimitri Maziuk <dmaziuk@xxxxxxxxxxxxx> wrote: > >>> At the start of the batch #cores-in-the-cluster processes try to mmap >>> the same 2GB and start reading it from SEEK_SET at the same time. I >>> won't know until I try but I suspect it won't like that. >> >> Well, it'll be #servers-in-cluster serving up 4MB chunks out of cache. >> It's possible you could overwhelm their networking but my bet is >> they'll just get spread out slightly on the first block and then not >> contend in the future. > > In the future the application spreads out the reads as well: running > instances go through the data at different speed, and when one's > finished, the next one starts on the same core & it mmap's the first > chunk again. > >> Just as long as you're thinking of it as a test system that would make >> us very happy. :) > > Well, IRL this is throw-away data generated at the start of a batch, and > we're good if one batch a month runs to completion. So if it doesn't > crash all the time every time, that actually should be good enough for > me. However, not all of the nodes have spare disk slots, so I couldn't > do a full-scale deployment anyway, not without rebuilding half the nodes. In that case you are my favorite kind of user and you should install and try it out right away! :D -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
