db_1:
  adapter: mysql2
  reconnect: false
  pool: 5
  username: <username>
  password: <password>
  database: database_test
  host: 101.101.101.1

db_2:
  adapter: mysql2
  reconnect: false
  pool: 5
  username: <username>
  password: <password>
  database: database_test
  host: 101.101.101.2

db_3:
  adapter: mysql2
  reconnect: false
  pool: 5
  username: <username>
  password: <password>
  database: database_test
  host: 101.101.101.3

class ExtDatabases < ActiveRecord::Base
        self.abstract_class = true
        establish_connection :db_1
end

class Users < ExtDatabases
        Users.table_name = "ext_users"
end