Channel is closed and never reopened when InternalConsumer.HandleModelShutdown triggers

Problem When a consumer is stuck for 30 minutes or longer (the default timeout after which RabbitMQ.Client automatically closes the channel¹), the IBasicConsumer.HandleModelShutdown method is triggered, which logs that the channel was closed. The channel never recovers or gets reopened, and any future messages are never consumed.

1. See https://www.rabbitmq.com/consumers.html#acknowledgement-timeout

Root Cause InternalConsumer (which is used by PersistentConsumer & friends) creates its own channel here: https://github.com/EasyNetQ/EasyNetQ/blob/f614ba6b555767ac1ae96c7405fb4bbca740e868/Source/EasyNetQ/Consumer/InternalConsumer.cs#L135

InternalConsumer does not emit an event of any kind when the channel is shutdown. (AQMP code is PreconditionFailed) After some digging, I found that there is a ChannelClosedEvent that gets emitted by PersistentChannel, but InternalConsumer does not emit this. InternalConsumer creates instances of IBasicConsumer, and these receive a callback on IBasicConsumer.HandleModelShutdown You can also register a callback via the ModelShutdown on IModel, which is what PersistentChannel does.

Suggested solution Emit ChannelClosedEvent on the IEventBus from InternalConsumer so that library users can handle this problem, and/or automatically create a new channel when this problem occurs so we can recover from this situation.

Using latest EasyNetQ 6.3.1

[Pliner]

The issue was resolved in v7.

[Pliner]

@amoerie just to start a discussion about the implementation #1327