Project: Message-driver 0.4.0

Publisher: Message Driver

DLQ-ing messages with nacks and consumers

@bunny

RabbitMQ supports sending messages to a DLQ if configured correctly.
See http://www.rabbitmq.com/dlx.html for details.

Given

the following broker configuration

MessageDriver::Broker.define do |b|
  # declare a dead letter exchange
  b.destination :rabbit_dlx, "rabbit.dead.letter.exchange", type: :exchange, declare: { type: :fanout }

  # declare a dead letter queue and bind it to the exchange
  b.destination :rabbit_dlq, "rabbit.dead.letter.queue", bindings: [
    { source: "rabbit.dead.letter.exchange" }
  ]

  # declare a work queue that sends dead letters to our dead letter queue
  b.destination :rabbit_work, "rabbit.work", arguments: { :"x-dead-letter-exchange" => "rabbit.dead.letter.exchange" }
end

And

I have no messages on :rabbit_work

And

I have no messages on :rabbit_dlq

Scenarios

Nacking a message with requeue false
Nacking a message on a manual_ack consumer
Raising a DontRequeueError in an auto_ack consumer
Raising a DontRequeueError in a transactional consumer

Nacking a message with requeue false

Given

I send the following message to :rabbit_work

body

Nack Test 1

When

I execute the following code

message = MessageDriver::Client.pop_message(:rabbit_work, client_ack: true)
message.nack(requeue: false)

Then

I expect to find no messages on :rabbit_work

And

I expect to find the following 1 message on :rabbit_dlq

body

Nack Test 1

Nacking a message on a manual_ack consumer

Given

I have a message consumer

MessageDriver::Client.consumer(:manual_dql) do |message|
  message.nack(requeue: false)
end

And

I create a subscription

MessageDriver::Client.subscribe(:rabbit_work, :manual_dql, ack: :manual)

When

I send the following messages to :rabbit_work

body

Manual Nack 1

Manual Nack 2

And

I let the subscription process

Then

I expect to find no messages on :rabbit_work

And

I expect to find the following 2 messages on :rabbit_dlq

body

Manual Nack 1

Manual Nack 2

Raising a DontRequeueError in an auto_ack consumer

Given

I have a message consumer

MessageDriver::Client.consumer(:manual_dql) do |message|
  raise MessageDriver::DontRequeueError
end

And

I create a subscription

MessageDriver::Client.subscribe(:rabbit_work, :manual_dql, ack: :auto)

When

I send the following messages to :rabbit_work

body

Auto Nack 1

Auto Nack 2

And

I let the subscription process

Then

I expect to find no messages on :rabbit_work

And

I expect to find the following 2 messages on :rabbit_dlq

body

Auto Nack 1

Auto Nack 2

Raising a DontRequeueError in a transactional consumer

Given

I have a message consumer

MessageDriver::Client.consumer(:transactional_dql) do |message|
  publish(:rabbit_work, "I get rolled back")
  raise MessageDriver::DontRequeueError
end

And

I create a subscription

MessageDriver::Client.subscribe(:rabbit_work, :transactional_dql, ack: :transactional)

When

I send the following messages to :rabbit_work

body

Transactional Nack 1

Transactional Nack 2

And

I let the subscription process

Then

I expect to find no messages on :rabbit_work

And

I expect to find the following 2 messages on :rabbit_dlq

body

Transactional Nack 1

Transactional Nack 2

Last published over 7 years ago by soupmatt.

DLQ-ing messages with nacks and consumers

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