Rails with multiple databases

code In database.yml
slave1:
host: 18.48.43.29 # your slave’s IP
database: production
username: root
password: pass
l Define a model Slave1.rb

class Slave1 < ActiveRecord::Base 
    self.abstract_class = true 
    establish_connection :slave1 
end 

When you need to run a query on the slave, just do
Slave1.connection.execute("select * from some_table")

Magic Multi-Connections Ruby on Rails ActiveRecords