Retry when publisher confirms fail

[KushalP]

We're currently monitoring publisher confirms as part of the QueueConnection object but aren't doing anything in the event that a given publish fails. You can see an example of how this can be done from the author of the amqp library we're using here: https://github.com/streadway/amqp/issues/104#issuecomment-46810166

[mattbostock]

Noting this here because I think it's relevant:

We set the mandatory and immediate flags to false when publishing a message.

This could lead to circumstances in which messages are silently dropped.

We may need to look at implementing a listener with Channel.NotifyReturn to handle any undeliverable messages when calling publish as per if we enable either of these flags: http://godoc.org/github.com/streadway/amqp#Channel.Publish

[KushalP]

Agreed. This is all related to the possibility that the AMQP server tells us it couldn't confirm receipt of a message.