The document provides a comprehensive overview of RabbitMQ, focusing on its implementation of the Advanced Message Queuing Protocol (AMQP) version 0-9-1. It covers foundational concepts such as message publishing, frames, and properties, along with advanced topics like message delivery methods, transactions, and common user problems. It also discusses extensions to the AMQP model and architectural benefits of adopting RabbitMQ for messaging systems.

1. Idiomatic RabbitMQ
Gavin M. Roy
VP of Architecture
AWeber Communications
Twitter: @Crad

2. To grok RabbitMQ is to know AMQP 0-9-1

3. Beginner Questions
How do I …
What is a …

4. Next Level Questions
Why do / does / is …

5. RabbitMQ’s Identity
Capabilities and behaviors

6. Advanced Message Queueing Model
Exchange
Receives and route messages
Message Queue
Store messages until they are consumed
Binding
Defines the relationship between the
exchange and queue
X
QueueBindingExchange

7. Advanced Message Queueing Protocol
Client Server
Protocol Header
Connection.Start
Connection.StartOk
Connection.Secure
Connection.SecureOk
Connection.Tune
Connection.TuneOk
Connection.Open
Connection.OpenOk
AMQP 0-8 to 0-9-1
RabbitMQ’s foundation

8. AMQP Classes and Methods
Connection
Start, StartOk, Close …
Channel
Open, Close, Flow …
Exchange
Declare, Bind, Unbind, Delete …
Queue
Declare, Bind, Purge …
Basic
Publish, Consume, Get, Recover …
TX
Select, Commit, Rollback …
Confirm
Select, SelectOk
Exceptions
Arguments to Channel.Close

9. AMQP Framing
0 335 0xce1 Frame Payload
The frame header is comprised of three parts, the
frame type, channel number and the frame size
The frame payload varies depending on the
frame type
There is a single byte marker to
specify the end of the frame

10. Message Publishing Anatomy
The Basic.Publish method frame tells RabbitMQ that a
client is going to publish a message and that it should
expect a Header frame with Basic.Properties in it
The content header frame carries the message properties and
tells RabbitMQ how big the message body is so that it can
process the correct number of body frames that are going to be
sent.
A single message published may contain
multiple body frames, depending on the
size of the content and the maximum
frame size setting
1 41 0xce1 Basic.Publish
1 82 0xce2 Content Header
1 55 0xce3 Body
Frame Type, Channel
and Byte Size
Frame Type, Channel
and Byte Size
Frame Type, Channel
and Byte Size

11. Basic.Publish Frame
The first two fields of the method frame
payload carry the Class and Method ID,
numeric values that represent the RPC
command.
The next part of the method frame
carries the first argument for the
method, in this case, the name of the
exchange to publish in to
The routing key value is the next
argument and provides information
for the exchange to route the
message into the appropriate queue
or queues.
Exchange Name Routing Key Value Mandatory Flag
The mandatory flag tells RabbitMQ
that it must be able to route the
message or it should send a
Basic.Return frame indicating the
message could not be routed.
Basic Publish
1 41 0xce1 Method Frame

12. Content Header Frame
The first field in a content header is the
body size, however this value is not
considered a property of the message
The flag values specify
which properties are set
The first property of the message,
the content-type is specified
The app_id property
is also specified
55 application/json Test 1144, 200 1014206880
The timestamp property is
specified, but is actually carried
as the binary packed value
The property delivery-mode with a value of
1 tells RabbitMQ to only keep the message
in memory when publishing to a queue
1 45 0xce2 Content Header Frame

13. Body Frame(s)
1 55 0xce3 Body
{"foo": "bar", "baz": "qux", "quux", "corge": "grault"}
The message body is opaque to the
AMQP protocol and is not decoded,
inspected, or evaluated by RabbitMQ

14. Message Publishing
How do you answer publishing questions?

15. Persisted
M
essages
Transactions
H
A
Q
ueues
Publisherconfirm
s
N
o
guarantees
N
otification
on
failureAlternate
exchanges
H
A
Q
ueues
w
/Transactions

16. Receiving Messages
Questioning how messages are delivered

17. G
etting
M
essages
C
onsum
ing
and
using
Transactions
C
onsum
e
w
ith
Acknow
ledgem
ents
C
onsum
ing
w
ith
"N
o
Ack
M
ode"enabled
C
onsum
ing
w
ith
Acknow
ledgem
ents
and
Q
oS
>
1

18. How will you use RabbitMQ?
Leverage the AMQ Model or Do-It Yourself

19. Use RabbitMQ and DYI
Contract and content in the message body

20. Use the AMQ Model
Message Properties and Routing

21. AMQ Model with RPC
C / PC / P
P / C
C / PResponse Queue
X
X
Worker
Queue
Message Properties
content-encoding
app-id
content-type
delivery-modecorrelation-id
expiration
message-id
headers
priority
user-id
reply-to
type
timestamp
cluster-id

22. AMQ Model with Message Firehose
Message Properties
content-encoding
app-id
content-type
delivery-modecorrelation-id
expiration
message-id
headers
priority
user-id
reply-to
type
timestamp
cluster-id
X
Image Hashing
Facial Detection
RPC Worker
P
image.new.profile
User Directory
Materialization
image.new.*
Auditing Worker
image.*.profile
image.# Image Removal
image.delete.*
image.new.profile

23. Common User Problems
• Not understanding the bidirectional nature
of AMQP
• Heartbeats?
• Throttling Messages
• How to use channels?
• Slow performance due to poor choices

24. AMQP Problems
• Currently 30 items in the 0-9-1 errata
• Logic Errors
• Marshaling incompatibilities between
0-9 && 0-9-1
• Behavior differences between 0-8 && 0-9-1
• Authentication Failure Notifications
• Client responsibilities

25. RabbitMQ Extensions
Building on top of the AMQ Model and Protocol

26. Federation
Exchanges
Queues
Downstream Broker / ClusterUpstream Broker / Cluster
P X Upstream Queue XC / P
Downstream Broker / ClusterUpstream Broker / Cluster
P X Upstream Queue C / P Downstream Queue C

27. Shovels
Exchanges
Queues
Destination Broker / ClusterSource Broker / Cluster
P X Source Queue C / P Destination Queue
Destination Broker / ClusterSource Broker / Cluster
P X Source Queue XC / P

28. Protocol Plugins
Client
AMQP 1.0
Server Plugin
Client
MQTT
Server Plugin
Client
STOMP
Server Plugin
Internal
AMQP 0-9-1
Client
Internal
AMQP 0-9-1
Client
Internal
AMQP 0-9-1
Client

29. AMQ Model & Protocol Extensions
• Queue Mirroring (HA Queues)
• Publisher Confirmations (Confirm.Select)
• Connection.Blocked and Connection.Unblocked
• Consumer Cancellation Notifications (Basic.Cancel behavior enhancement)
• Negative Acknowledgements (Basic.Nack)
• Exchange to Exchange Bindings (Exchange.Bind && Exchange.Unbind)
• Direct Reply-To

30. AMQ Model & Protocol Extensions (Continued)
• Authentication Failure Notifications
• Alternate Exchanges
• Dead Letter Exchanges
• Sender Selected Distribution (CC & BCC in Headers Property)
• Time-to-live for messages and queues
• Maximum Queue Lengths
• Priorities (different implementation than specified)

31. Architectural Impact of
Embracing AMQP
• Simplicity
• Extensibility
• Robustness
• Flexibility

32. Use of Message Properties
Robustness by describing content
Content-Encoding, Content-Type, and Type
Traceability by identifying messages
Correlation-ID and Message-ID
Better debugging by identifying sender
and time of publishing
App-ID, Timestamp, and User-ID
Message Properties
content-encoding
app-id
content-type
delivery-modecorrelation-id
expiration
message-id
headers
priority
user-id
reply-to
type
timestamp
cluster-id

33. Message Flexibility
Same message, multiple simple consumer types

34. Questions?
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