(작성중)
[Introduction]
AMQP is an open standard application layer protocol for messaging middleware.
AMQP is a standard wire-level protocol and semantic framework for high performance enterprise messaging.
- provides flow controlled, message-oriented communication with message-delivery guarantees.
: at-most-once (where each message is delivered once or never)
: at-least-once (where each message is certain to be delivered, but may do so multiple times)
: exactly-once (where the message will always certainly arrive and do so only once)
- Authentication / encryption based on SASL / TLS.
- It assumes an underlying reliable transport layer protocol such as Transmission Control Protocol (TCP).
[History]
- AMQP was originated in 2003 by John O'Hara at JPMorgan Chase & Co. in London, UK
- The version history of the AMQP
. 0-8, published in June 2006
. 0-9, published in December 2006
. 0-10 published in February 2008
. 0-9-1, published in November 2008.
* These earlier releases are significantly different from the final 1.0 specification
- AMQP 1.0 was released by the AMQP Working Group on 30 October 2011, at a conference in New York.
- 1 November 2011, the formation of an OASIS Technical Committee was announced to advance this contributed AMQP version 1.0 through the international open standards process.
. The first draft from OASIS was released in February 2012 .
. The second draft was released for public review on 20 June, 2012 .
. AMQP was approved as an OASIS standard on the 31st October, 2012 .
[Transport Conceptual Model]
- An AMQP network consists of nodes connected via links.
: Nodes are named entities responsible for the safe storage and/or delivery of messages.
: Messages can originate from, terminate at, or be relayed by nodes.
- A link is a unidirectional route between two nodes.
- The link protocolmanages the transfer of responsibility between the source and target.
+------------+ +------------+
/ Node A \ / Node B \
+----------------+ +--filter +----------------+
| | / | |
| MSG_3 <MSG_1> | _/ _ | MSG_1 |
| |(_)------------------>(_)| |
| <MSG_2> MSG_4 | | | | MSG_2 |
| | | Link(Src,Tgt) | | |
+----------------+ | | +----------------+
| |
Src Tgt
Key: <MSG_n> = old location of MSG_n
- Nodes exist within a container.
- Examples of containers are brokers and client applications.
: Each container MAY hold many nodes.
: Producers and consumers are the elements within an application that generate and process messages.
: Queues are entities that store and forward messages.
+---------------+ +----------+
| <<Container>> | 1..1 0..n | <<Node>> |
|---------------|<>-------------------->|----------|
| container-id | | name |
+---------------+ +----------+
/_\ /_\
| |
| |
+-----+-----+ +----------+----------+
| | | | |
| | | | |
+--------+ +--------+ +----------+ +----------+ +-------+
| Broker | | Client | | Producer | | Consumer | | Queue |
|--------| |--------| |----------| |----------| |-------|
| | | | | | | | | |
+--------+ +--------+ +----------+ +----------+ +-------+
[Protocol Frames]
Frame Connection Session Link
========================================
open H
begin I H
attach I H
flow I H
transfer I H
disposition I H
detach I H
end I H
close H
----------------------------------------
Key:
H: handled by the endpoint
I: intercepted (endpoint examines
the frame, but delegates
further processing to another
endpoint)
[Frame Layout]
REQUIRED OPTIONAL OPTIONAL
+--------------+-----------------+------------+ | frame header | extended header | frame body | +--------------+-----------------+------------+ 8 bytes *variable* *variable*
+--------------+-----------------+------------+ | frame header | extended header | frame body | +--------------+-----------------+------------+ 8 bytes *variable* *variable*
- General frame layout
+0 +1 +2 +3
+-----------------------------------+ -.
0 | SIZE | |
+-----------------------------------+ |---> Frame Header
4 | DOFF | TYPE | <TYPE-SPECIFIC> | | (8 bytes)
+-----------------------------------+ -'
+-----------------------------------+ -.
8 | ... | |
. . |---> Extended Header
. <TYPE-SPECIFIC> . | (DOFF * 4-8) bytes
| ... | |
+-----------------------------------+ -'
+-----------------------------------+ -.
4*DOFF | | |
. . |
. . |
. . |
. <TYPE-SPECIFIC> . |---> Frame Body
. . | (SIZE-DOFF*4) bytes
. . |
. . |
. ________| |
| ... | |
+--------------------------+ -'
- AMQP frame layout
type: 0x00 - AMQP frame
+0 +1 +2 +3
+-----------------------------------+ -.
0 | SIZE | |
+-----------------------------------+ |---> Frame Header
4 | DOFF | TYPE | CHANNEL | | (8 bytes)
+-----------------------------------+ -'
+-----------------------------------+ -.
8 | ... | |
. . |---> Extended Header
. <IGNORED> . | (DOFF*4-8)bytes
| ... | |
+-----------------------------------+ -'
+-----------------------------------+ -.
4*DOFF | PERFORMATIVE: | |
. Open / Begin / Attach . |
. Flow / Transfer / Disposition . |
. Detach / End / Close . |
|-----------------------------------| |
. . |---> Frame Body
. . | (SIZE-DOFF*4)bytes
. PAYLOAD . |
. . |
. ________| |
| ... | |
+--------------------------+ -'
[Messaging]
뭔소린지 모르겠다..
- Message format
Bare Message | .-------+-------. | | +---+---+---+---+---+---+---+
Bare Message | .-------+-------. | | +---+---+---+---+---+---+---+
| h | d | m | p | a | a | f |
| e | e | e | r | p | p | o |
| a | l | s | o | p | p | o |
| d | i | s | p | l | l | t |
| e | v | a | e | i | i | e |
| r | e | g | r | c | c | r |
| | r | e | t | a | a | |
| | y | | i | t | t | |
| | - | - | e | i | i | |
| | a | a | s | o | o | |
| | n | n | | n | n | |
| | n | n | | - | - | |
| | o | o | | p | d | |
| | t | t | | r | a | |
| | a | a | | o | t | |
| | t | t | | p | a | |
| | i | i | | e | | |
| | o | o | | t | | |
| | n | n | | i | | |
| | s | s | | e | | |
| | | | | s | | |
+---+---+---+---+---+---+---+
| |
'-------------+-------------'
|
Annotated Message
* 자세한것은 스펙 다시 보는게 빠를듯..
- AMQP became the standard as the OASIS Advanced Message Queuing Protocol
- AMQP Working Group License, OASIS copyright
- Advanced Message Queuing Protocol Protocol Specification, Version 0-9-1, 13 November 2008
모르겠다.. 쉽게 볼 수 있는게 아닌것 같다..
프로토콜도 복잡하고 option마다 message format이 다양해서..
