>>> assuming that each user loads 40 files in 1 minute we get >>> 12000*60/40=18 000 users per minute >>> >>> Is it possible to get half of that 18k users/per minute in real word >>> ignoring the amounts of traffic it will generate ? >> >> I'd say so, but it depends on how big the data set is. If you can store it >> in memory, varnish is ridiculously fast. I also wouldn't recommend relying > i think it will fit in to ram, i will be a single site > >> on a single Varnish for more than a few thousand requests per second. If >> something goes wrong (suddenly getting lots of misses for instance), it >> will quickly spread. >> >> For comparison, I'm looking at a box with roughly 0.4 load serving >> 2000req/s as we speak, and that's on 2xDual Core Opteron 2212. Going by >> those numbers, it should theoretically be able to handle almost ten times >> as many requests if Varnish scaled as a straight line. >> >> That'd give you roughly 18000 req/s at peak (give or take a little...) Now >> you're talking about 8 cores, that should be 36k req/s. That's _not_ >> unrealistic, from what we've seen in synthetic tests. If each client >> requires 40 items, that means roughly 900 clients _per second_. Or 54k in a >> minute. This math is all rough estimates, but the foundation is production >> sites and real traffic patterns. >> >> The problem is that getting your Varnish to deal with 36k req/s is rather >> difficult, and you quickly run into network issues and similar. And at 36k >> req/s you can hardly take any amount of backend traffic or delays before it >> all falls over.
today i did some ad-hoc tests with 45 byte body, when I enable keep-alive I'm getting 39k req/s with 100 concurrent gets and over 40k with 300 concurrent connections (max cpu load was under 2 cores for varnish) without keep alive i'm stuck with 12k req/s, that might be end of ab's performance in making new connections or kernel, i tried the performance tips from the wiki, but id didn't make a significant difference in this test, Later i will try to use a benchmark running on another machine. 12k req/s is more then enough for me already so I'm happy with that -- Michal Grzedzicki _______________________________________________ varnish-misc mailing list [email protected] http://projects.linpro.no/mailman/listinfo/varnish-misc
