JSON-RPC

Brno Ruby Users Group April 2012

Mo Morsi :: <mo@morsi.org> :: http://mo.morsi.org

Or How I Learned To Stop Worrying And Love RPC

The Problem With RPC Today

It's complicated:

SOAP
Corba

The Problem With RPC Today

It's platform specific:

Distributed Ruby / RPyC
Java Remote Method Invocation
Windows Communication Foundation

The Problem With RPC Today

It's transport specific:

XMLRPC (http post)
REST (http)
QMF (amqp)

!!!! JSON-RPC !!!!

JSON-RPC

simple: very easy to understand
(protocol is < 10 pages printed)
readable: messages are just json objects
extensible: very easy to add new fields to the messages and responses to support any number of features

JSON-RPC

transport independent: use it over http, amqp, or even plain old tcp/udp
platform independent: very simple to implement in any language, already done for many of the major languages
supports synchronous and asynchronous messages

Typical JSON-RPC Request

--> {"jsonrpc": "2.0", "method": "subtract", "params": [23, 42], "id": 2}

<-- {"jsonrpc": "2.0", "result": -19, "id": 2}

Using it from ruby

gem install rjr

<shameless-self-promotion>

Using it from ruby

$ irb > RJR::Dispatcher.add_handler("hello") { |arg| arg.upcase } > amqp_node = RJR::AMQPNode.new :node_id => 'server', :broker => 'localhost' > amqp_node.listen > amqp_node.join

$ irb > amqp_node = RJR::AMQPNode.new :node_id => 'client', :broker => 'localhost' > puts amqp_node.invoke_request('server-queue', 'hello', 'world')

Using it from javascript

$ irb > RJR::Dispatcher.add_handler("hello") { |arg| arg.upcase } > amqp_node = RJR::AMQPNode.new :node_id => 'server', :broker => 'localhost' > ws_node = RJR::WSNode.new :node_id => 'server', :host => 'localhost', :port => 8080 > www_node = RJR::WebNode.new :node_id => 'server', :host => 'localhost', :port => 8888 > multi_node = RJR::MultiNode.new :nodes => [amqp_node, ws_node, www_node] > multi_node.listen > multi_node.join

Using it from javascript

z, ?	toggle help (this)
space, →	next slide
shift-space, ←	previous slide
d	toggle debug mode
## <ret>	go to slide #
c, t	table of contents (vi)
f	toggle footer
r	reload slides
n	toggle notes
p	run preshow

JSON-RPC

Or How I Learned To Stop Worrying And Love RPC

The Problem With RPC Today

The Problem With RPC Today

The Problem With RPC Today

!!!! JSON-RPC !!!!

JSON-RPC

JSON-RPC

Typical JSON-RPC Request

Using it from ruby

gem install rjr

Using it from ruby

Using it from javascript

Using it from javascript

JSON-RPC FTW!

http://mo.morsi.org

Questions?