Ruby amqp gem is a widely used, feature-rich, well-maintained asynchronous RabbitMQ client with batteries included. This library works with
and is licensed under the Ruby License
0.8.0 and later versions of amqp gem implement AMQP 0.9.1 (see also AMQP 0.9.1 spec document) and support RabbitMQ extensions to AMQP 0.9.1.
See Getting started with amqp gem and other amqp gem documentation guides. We recommend that you read AMQP 0.9.1 Model Explained, too.
RabbitMQ is an open source messaging middleware that emphasizes interoperability between different technologies (for example, Java, .NET, Ruby, Python, Node.js, Erlang, Go, C and so on).
Key features of RabbitMQ are very flexible yet simple routing and binary protocol efficiency. RabbitMQ supports many sophisticated features, for example, message acknowledgements, queue length limit, message TTL, redelivery of messages that couldn't be processed, load balancing between message consumers and so on.
One can use amqp gem to make Ruby applications interoperate with other applications (both Ruby and not). Complexity and size may vary from simple work queues to complex multi-stage data processing workflows that involve dozens or hundreds of applications built with all kinds of technologies.
Specific examples:
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Events collectors, metrics & analytics applications can aggregate events produced by various applications (Web and not) in the company network.
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A Web application may route messages to a Java app that works with SMS delivery gateways.
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MMO games can use flexible routing AMQP provides to propagate event notifications to players and locations.
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Price updates from public markets or other sources can be distributed between interested parties, from trading systems to points of sale in a specific geographic region.
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Content aggregators may update full-text search and geospatial search indexes by delegating actual indexing work to other applications over AMQP.
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Companies may provide streaming/push APIs to their customers, partners or just general public.
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Continuous integration systems can distribute builds between multiple machines with various hardware and software configurations using advanced routing features of AMQP.
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An application that watches updates from a real-time stream (be it markets data or Twitter stream) can propagate updates to interested parties, including Web applications that display that information in the real time.
Please refer to the RabbitMQ installation guide. Note that for Ubuntu and Debian we strongly advice that you use RabbitMQ apt repository that has recent versions of RabbitMQ. RabbitMQ packages Ubuntu and Debian ship with are outdated even in recent (10.10) releases. Learn more in the RabbitMQ versions guide.
On Microsoft Windows 7
gem install eventmachine
gem install amqp
On other OSes
gem install amqp
#!/usr/bin/env ruby
# encoding: utf-8
require 'amqp'
EventMachine.run do
connection = AMQP.connect(:host => '127.0.0.1')
puts "Connecting to RabbitMQ. Running #{AMQP::VERSION} version of the gem..."
ch = AMQP::Channel.new(connection)
q = ch.queue("amqpgem.examples.hello_world", :auto_delete => true)
x = ch.default_exchange
q.subscribe do |metadata, payload|
puts "Received a message: #{payload}. Disconnecting..."
connection.close {
EventMachine.stop { exit }
}
end
x.publish "Hello, world!", :routing_key => q.name
endGetting started guide explains this and two more examples in detail, and is written in a form of a tutorial. See AMQP 0.9.1 Model Explained if you want to learn more about RabbitMQ protocol principles & concepts.
We believe that in order to be a library our users really love, we need to care about documentation as much as (or more) code readability, API beauty and autotomated testing across 5 Ruby implementations on multiple operating systems. We do care about our documentation: if you don't find your answer in documentation, we consider it a high severity bug that you should file to us. Or just complain to @rubyamqp on Twitter.
Getting started guide is written as a tutorial that walks you through 3 examples:
- The "Hello, world" of messaging, 1-to-1 communication
- Blabbr, a Twitter-like example of broadcasting (1-to-many communication)
- Weathr, an example of sophisticated routing capabilities AMQP 0.9.1 has to offer (1-to-many or many-to-many communication)
all in under 20 minutes. AMQP 0.9.1 Concepts will introduce you to protocol concepts in less than 5 minutes.
Documentation guides describe the library itself as well as AMQP concepts, usage scenarios, topics like working with exchanges and queues, error handing & recovery, broker-specific extensions, TLS support, troubleshooting and so on. Most of the documentation is in these guides.
You can find many examples (both real-world cases and simple demonstrations) under examples directory in the repository. Note that those examples are written against version 0.8.0.rc1 and later. 0.6.x and 0.7.x may not support certain AMQP protocol or "DSL syntax" features.
There is also a work-in-progress Messaging Patterns and Use Cases With AMQP documentation guide.
API reference is up on rubydoc.info and is updated daily.
We cover Web application integration for multiple Ruby Web servers in Connecting to the broker guide.
- Join also RabbitMQ mailing list (the AMQP community epicenter).
- Join Ruby AMQP mailing list
- Follow @rubyamqp on Twitter for Ruby AMQP ecosystem updates.
- Stop by #rabbitmq on irc.freenode.net. You can use Web IRC client if you don't have IRC client installed.
Upgrading from amqp gem 0.6.x and 0.7.x to 0.8.0+ is straightforward, please see amqp gem 0.8.0 migration guide. The same guide explains amqp gem versions history and why you would want to upgrade.
amqp gem is maintained by Michael Klishin.
AMQP gem is licensed under the Ruby License.
- The Original Code is tmm1/amqp.
- The Initial Developer of the Original Code is Aman Gupta.
- Copyright (c) 2008 - 2010 Aman Gupta.
- Contributions from Jakub Stastny are Copyright (c) 2011-2012 VMware, Inc.
- Copyright (c) 2010 — 2012 ruby-amqp group members.
Currently maintained by ruby-amqp group members Special thanks to Dmitriy Samovskiy, Ben Hood and Tony Garnock-Jones.
- AMQP 0.9.1 Model Explained
- RabbitMQ tutorials that demonstrate interoperability
- Wikipedia page on AMQP
- AMQP quick reference
- John O'Hara on the history of AMQP
- Enterprise Integration Patterns, a book about messaging and use of messaging in systems integration.
- A Critique of the Remote Procedure Call Paradigm
- A Note on Distributed Computing
- Convenience Over Correctness
- Joe Armstrong on Erlang messaging vs RPC
This library is developed and tested primarily with RabbitMQ, although it should be compatible with any server implementing the AMQP 0.9.1 spec. For AMQP 0.8 brokers, use amqp gem version 0.7.x.
In order to make code like the following (pseudo-synchronous) work
conn = AMQP.connect
ch = AMQP::Channel.new(conn)
ex = ch.default_exchange
ex.publish(some_data)and not be affected by this Ruby 1.8.7-p249-specific bug (super called outside of method), we need to avoid any inheritance for key amqp gem classes: Channel, Queue, Exchange, Consumer. This will take a significant refactoring effort and we do not expect this to change at this time.