Add another maxretry handler which does not create additional exchanges

[nevesenin]

No description provided.

[Spaceghost]

I bet to get this merged, it'll be helpful to convert from rspec back into minitest like. If you'd like some help with this, I could either pair with you on it or I might be able to take a look and try to convert it myself. If you're not merged in by then, I'll pull request to your branch.

[nevesenin]

Hi, I don't have much experience with minitest. To be honest, I don't know what you mean.

[adis-io]

@nevesenin
Could you explain why we need to change original payload?

[nevesenin]

To add debug information in case of an error.

[JanStevens]

Cool, how does this differ in terms of the existing max retry exchange?
It does not create extra exchanges but does this have a performance penalty? Any change you can draw some topology out?

thanks looks interesting!

[JanStevens]

After some experimenting a couple of pointers for other people that want to try:

when making a worker you must add the following arguments:

class Worker
    from_queue :foo, handler: Sneakers::Handlers::RoutingMaxretry,
      arguments: { 
        'x-dead-letter-exchange' => "exchange", 
        'x-dead-letter-routing-key' => "queue.foo.retry" 
      }
    # ...
end

Notice that its .retry and not -retry as with the current maxretry handler

Next, wildcard route matching is quite dangerous. I had a general routing key from my exchange to foo using # but this creates an endless feedback loop. If any of your defined routing_keys also match the following then you might have problems (I'm using example queue name foo):

• queue.foo.error
• queue.foo.requeue
• queue.foo.retry

[TheBerg]

I am working on using this, but when an error goes to the error queue bunny errors and gives me a IOError: not opened for reading error. I am investigating but just thought I would post here if anyone has got an idea. :)

[TheBerg]

It was something with how error_payload was generated. Since I want the original payload then overriding this method to just return payload fixed it for me.