Some of My Favourite httperf Tricks

Performance testing a site with the same traffic pattern that the site is actually getting from users is a huge plus. To do this, we first ask Varnish to create an access log for us to play with:

$ varnishncsa -d | \
  awk '{print $7}' | \
  tr "\n" "\0" \
  > /tmp/access_log-$(date --iso).httperflog

This httperf log can then be used to re-play the user traffic when running httperf.

$ httperf \
--server example.com \
--wlog=y,/tmp/access_log-2012-06-04.log.httperflog \
--num-conns=2000 \
--rate=20 \
--num-calls=30 \
--hog

This will makehttperf set up 2000 TCP connections, creating20 of them each second until it reaaches2000. It will then make 30 requests (calls) inside each TCP connetions, selecting a new URI from the httperf log file each time. When it reaches the bottom of the file, it will start at the top (that's they parameter). Lastly, it's agressivelyhogging all the TCP connections (i.e. local ports) it needs to get to2000 TCP connetions.

Of course, you probably want to runhttperf from a different host on a different network.