The C10k problem is absolutely not irrelevant, and certainly not because one page only saw 800rps during a worldwide event. Two things there: (1) 800rps TO THA

The C10k problem is absolutely not irrelevant, and certainly not because one page only saw 800rps during a worldwide event. Two things there: (1) 800rps TO THAT PAGE is the metric. The entire rest of Wikipedia was still getting traffic, and as an educated guess I would estimate raw traffic to be on the order of magnitude of 3-4krps (across editing and views). They are quite open with operations and if I weren't mobile I could probably find the accurate answer. (2) There are much higher traffic properties. I'm aware of one property beyond 200krps in aggregate. If you had said "most people don't have to worry about C10k," then I'm on board. That's true. Irrelevant? Far from it. And yes, query rate and connection count have a complicated relationship. You need three or four other metrics to explain their relationship, but raw query rate is a good yardstick for active connections when combined with quantiled request latency. (Not averaged.) Simple example: a 750ms 95th% page hit 10,000 times per second is almost certainly far > C10k because of the outliers. Now I will grant that C10k itself is somewhat irrelevant, yes, but not for the reason you are saying. It was defined in an age when 10,000 active connections was pretty surprising (didn't it come from FTP or some other heavy eyeball protocol?). These days with long poll apps, long-running protocols, and so on, millions of open connections are quite common at consumer scale. I find C1M far more interesting these days. C10M is still kinda nuts, but does exist in the magical world of metal and fiber and hot aisles and all those great things that nobody uses anymore (depressingly).