Manage multiple databases in Rails. Connect to different DB based on the model. http://stackoverflow.com/questions/6122508/connecting-rails-3-1-with-multiple-databases, http://ilikestuffblog.com/2012/09/21/establishing-a-connection-to-a-non-default-database-in-rails-3-2-2/, https://www.linkedin.com/groups/Multiple-Databases-Rails-31-120725.S.554…

database.yml

db1_production:
  adapter: mysql2
  encoding: utf8
  database: db1
  username: user_db1
  password: mypass
  host: localhost
  timeout: 5000

db2_production:
  adapter: mysql2
  encoding: utf8
  database: db2
  username: user_db2
  password: mypass
  host: other_host
  timeout: 5000

database_connections.rb

module DatabaseConnections
  class Db1 < ActiveRecord::Base 
    self.abstract_class = true 
    establish_connection configurations["db1_#{Rails.env}"] 
  end 
  
  class Db2 < ActiveRecord::Base 
    self.abstract_class = true 
    establish_connection configurations["db2_#{Rails.env}"] 
  end 
end 

model_stored_in_db1.rb

class ModelStoredInDb1 < DatabaseConnections::Db1
end

model_stored_in_db2.rb

class ModelStoredInDb2 < DatabaseConnections::Db2
end