[development] 2k qps

[Khalid B]

I have another client site that shoots  up to 3,000 QPS, but I don't have
the statistics of page access for it. This one has 4 Xeons 3.2GHZ each
and 4GB.

Write a simple script to run vmstat every 15 seconds or so, log the
output to a file. Keep it running until the "hang" happens, and then
see what it tells you about the system. Are you out of CPU? Do
you have too many blocked processes or runable processes?
Do you have a lot of wait on i/o? Are you swapping to the point of
thrashing.

Only after you do this analysis you should decide whether to
upgrade the RAM or just tune things.

Regarding decreasing the number of Apache processes, yes, that
means you can only serve so many users, but you prevent the chaos
caused by swapping. Think of it as a popular restaurant. If they let
in more people than they have tables/seats, would the customer be
happy? Would the staff cope with it?