Every time I see this graph I am a little bit tempted to puke.
There is only the barest explanation of what the test means, and as far as I can understand the circumstances of the test are not like those typically encountered by web servers, even those under extremely high load.
On top of that, this graph measures performance, not scalability. So it's saying, if you really want to perform, where by "perform" we mean have 4000 HTTP server sockets open concurrently, use YAWS not Apache.
If you can think of a methodology that won't make you puke, please suggest it. Yaws is easy to install on most platforms (like "apt-get install yaws") and very easy to configure. Maybe in the academic sense you can poke holes in the methodology, but in the practical world I can't think of a more clever way to test real load. When it boils down to it Yaws would be much more likely survive a digg effect or DoS attack, period.
There is only the barest explanation of what the test means, and as far as I can understand the circumstances of the test are not like those typically encountered by web servers, even those under extremely high load.
On top of that, this graph measures performance, not scalability. So it's saying, if you really want to perform, where by "perform" we mean have 4000 HTTP server sockets open concurrently, use YAWS not Apache.
Whoop dee doo!