Feedback on my article about how to safely consume RabbitMQ messages with Broadway

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1

I have recently wrote a blog post about my solution to a problem that we face internally consuming RabbitMQ messages with Broadway where if a crash occurred in the code the code would enter in an infinite loop: http://www.ubazu.com/consume-rabbit-mq-messages-from-elixir
Can you guys provide me some feedback regarding my idea and my code. Is anyone else encountered the same problem?

2

I’ve only read articles about Broadway, never used it in production, so I can’t speak to the specific functionality here. Some more general code notes:

def handle_message(_, %Message{data: string_payload} = message, _) do
  apply(unquote(module), :handle_message, [string_payload])
  message
  # I rescue any crash and move the message to the other queue
rescue
  e ->

Beware: there are more ways to crash than rescue deals with: see GenServer timeout and retry for recent discussion

exchange_fct = Keyword.get(opts, :exchange)
exchange = exchange_fct.()

This pattern happens often enough that it feels like it should be named.

3

Thanks for the tip with rescue. I have switched my code to use catch/2 to cover all the cases.