On Sat, Jan 16, 2010 at 4:27 PM, Michael Fischer <[email protected]> wrote: > On Sat, Jan 16, 2010 at 4:16 PM, Michael Fischer <[email protected]> > wrote: >> >> On Sat, Jan 16, 2010 at 4:10 PM, David Birdsong <[email protected]> >> wrote: >>> >>> On Sat, Jan 16, 2010 at 3:55 PM, Michael Fischer <[email protected]> >>> wrote: >>> > This scheme seems very baroque. Why not just reduce the size of your >>> > caches >>> > so you don't page-thrash and let Varnish's builtin LRU algorithm handle >>> > the >>> > eviction? >>> >>> Then I wont be able to cache nearly as much. I want to originate as >>> much content as possible on the varnish servers ie. reduce backend >>> fetches. There is no way I could fit any useful amount of my working >>> set into a storage that could handle the evictions without spending an >>> unreasonable amount of money (basically fit it in RAM.) -I'd love to >>> be proven wrong though. As far as random reads go, the SSD's are >>> really good; it's just the writes that kill me. >>> >>> Right now a mostly filled cache server with ~80-160GB allocated can >>> maintain between 90-92% cache hit ratio at 400-500Mb/sec. When it >>> fills up completely eviction cause the machine to keel over, parent >>> can't ping the child, health checks fail -general badness. I'd like >>> to let the eviction run under supervision (automated supervision) and >>> augment the eviction such that it buys back a few hours not minutes. >> >> What OS are you running? This might be one of those rare cases where a >> little more "swappiness" (i.e., aggressiveness of the pageout algorithm) >> might buy you something. > > This page may be useful if you're running on Linux: > http://www.westnet.com/~gsmith/content/linux-pdflush.htm > --Michael
yes, this page was very helpful back when I had hopes of tuning my way around this load problem. _______________________________________________ varnish-misc mailing list [email protected] http://projects.linpro.no/mailman/listinfo/varnish-misc
