Under pressure, debuging a production system, given the following question:
"How many new connections per second are we creating to S3?".
My one-liner (Linux):
while true; do diff <(netstat -an | grep ESTAB | grep ":443 "| grep -v "N.N.N.N:443 " | sort) <(sleep 1; netstat -an | grep ESTAB | grep ":443 "| grep -v "N.N.N.N:443 " | sort) | grep "<" | wc -l;sleep 1;done
Where N.N.N.N is the local IP. Many better ways to do this, but I had this in a few minutes.
Done.