[marcusf]

So you had 500m reads on a relatively static data set + 5m writes on an unrelated log? Sounds like a fun problem, but I agree I doesn't sound like rocket science. On the other hand, it also doesn't sound like Twitter, having 400m writes per day, and 400*x million reads on that very dynamic data set. Just seems that's a slightly harder problem.

[chewxy]

Adserving is not really static. Cachebusters are named so for good reason. Nowadays ad server developers are clever enough to separate click tracking and impression tracking (the non-Enterprise version of OpenX still deserves a lot of ಠ_ಠ though).

In an RTB environment, there is an additional constraint of having to serve up your ad (or decision) within 60ms (Google ADX sets a hard limit of 80ms), and the fastest best bid wins.

I don't think that's a less hard problem compared to Twitter, especially at high volumes. You can't just say "scale sideward!".

That said, the first link was totally misleading. I was actually quite shocked to see that Twitter only had 42M uniques per month, because a typical ad network does a lot more

EDIT: ah.. 15B requests/day makes more sense. Wtf is with the wrong stats?

[achompas]

Are you talking about 15B vs. the visits chart I linked? If so, the 15B number comes from API calls, which do not have to happen through the website (think of all the Twitter clients).

[chewxy]

Requests are requests.15B is a gigantic amount.

[achompas]

Right I agree 100%. I just couldn't tell if you were trying to reconcile the 15B with the 45M number from Compete.