unicorn-instruments

This is a hack in order to account for the total time spent in ruby while processing http requests.

gem 'unicorn-instruments'

Require the gem in your unincorn config file.

config/unicorn.rb

require 'unicorn-instruments'
...

Start a timer.
Call accept().
Call send().
Close socket.
Stop timer.
Print Elapsed time.

If the timer elapsed for 4ms, the following log line will be printed:

measure=unicorn.process val=4

Using this data with l2met you can plot the unicorn processing time with the router service time. The difference between the values will be the time spent in the Heroku network.