In Windows for ASP, you can get it perfmon, but...
How to get \"requests per second\" for Apache in Linux?
Script shows inconsistent numbers. -f parameter affects output a lot! and first reading is not accurate either.
-f
I ended up using:
while true; do tail -n0 -f access.log>/tmp/tmp.log & sleep 2; kill $! ; wc -l /tmp/tmp.log | cut -c-2; done 2>/dev/null
Found here.