How to count dropped connections

[Amos Shapira]

Hello,

We are running a cluster of web servers of various functions on top of
CentOS 5, and would like to know whether and how many requests we
might be dropping because of insufficient provisioning. The cluster
could be hit by a a few millions requests per day soon and we'd like
the stats to be there both now (in case we miss something obvious) and
when the crowd comes charging.

Googl'ing around for explanations of "netstat -s" and the files under
/proc/net didn't come up with anything which looks like the definite
answer, except maybe "packets pruned from receive queue because of
socket buffer overrun", but I'm not sure what it counts.

Does anyone know how to get the stats I want?

Thanks,

--Amos