A UK company called GoCardless has just open sourced a library that became very crucial to their direct debit software's infrastructure as they built it out. The tool is a Ruby library called Hutch, and here's what it does:
Hutch is a Ruby library for enabling asynchronous inter-service communication in a service-oriented architecture, using RabbitMQ.
-- Harry Marr
You can take it for a spin by visiting the GitHub repo. The blog post about the release on GoCardless.com gives a case study of how their architecture evolved with Hutch. There was also a tweet from Marr that revealed a little more about the message volume on their broker cluster:
@timblair cheers! We’re using mirrored queues (possibility for dup messages, so consumers are idempotent). Volume is spiky, peak ~5k/s.— Harry Marr (@harrymarr) September 10, 2013