AwsSdbProxy

AwsSdbProxy is a HTTP proxy server bridging ActiveResource calls from Rails to Amazon’s SimpleDB Web Service allowing SimpleDB to be used as a storage backend for Rails applications.

The proxy will listen on a configurable port for web service calls initiated by ActiveResource models and forward the requests to SimpleDB using the aws-sdb Gem by Tim Dysinger.

Installation

Install the AwsSdbProxy plugin from Rubyforge[http://www.rubyforge.org] as usual:

 script/plugin install http://rug-b.rubyforge.org/svn/aws_sdb_proxy

Setup and Usage

1. Enter your Amazon Web Service credentials in the config/aws_sdb_proxy.yml config file (optionally configure server ports and a salt used to hash primary keys from the record content).
2. Check your available SimpleDB domains with rake aws_sdb:list_domains and create a new one with rake aws_sdb:create_domain DOMAIN=my_new_domain if necessary.
3. Start the AwsSdbProxy server with rake aws_sdb:start_proxy_in_foreground. (Once things are configured correctly you can also use rake aws_sdb:start_proxy to start the server as a background daemon.)
4. Connect any ActiveResource model to your SimpleDB domain, e.g.

    class Post < ActiveResource::Base
      self.site = "http://localhost:8888" # AwsSdbProxy host + port
      self.prefix = "/my_new_domain/"     # use your SimpleDB domain enclosed in /s
    end
   

5. Use your model just like any ActiveResource model in your application or try it in script/console, e.g.

    >> p = Post.create(:title => 'My first SimpleDB post')
    => #<Post:0x198ceec @prefix_options={}, @attributes={"updated_at"=>
    Sun Jan 20 00:42:43 UTC 2008, "title"=>"My first SimpleDB post",
    "id"=>1081408...01005954, "created_at"=>Sun Jan 20 00:42:43 UTC 2008}>
   
    >> p.body = 'Content is king'
    => "Content is king"
   
    >> p.save
    => true
   
    >> Post.find(:first, :params => { :title => 'My first SimpleDB post' })
    => #<Post:0x18efef8 @prefix_options={}, @attributes={"updated_at"=>
    Sun Jan 20 00:45:28 UTC 2008, "title"=>"My first SimpleDB post",
    "body"=>"Content is king", "id"=>1081408...01005954, "created_at"=>
    Sun Jan 20 00:42:43 UTC 2008}>
   

Background

As you may have noticed SimpleDB (and thus AwsSdbProxy) do not use any pre-defined schema. Every record can potentially have different attributes. SimpleDB also has no data types associated with it’s attributes, all data will be stored as strings.

AwsSdbProxy adds a special _resource attribute to distinguish diffent models within the same SimpleDB domain and also adds and handles the usual created_at and updated_at attributes. Record ids are generated using a SHA512 hash function to make key collisions extremely unlikely.

Copyright © 2008 mailto:martin.rehfeld@glnetworks.de, released under the MIT license

Owner: Martin Rehfeld

Home: http://inside.glnetworks.de/2008/01/20/bridging-rails-to-amazon-simpledb-using-activeresource/

Repository: http://rug-b.rubyforge.org/svn/aws_sdb_proxy/

License: Rails' (MIT)

Category: Model