master_slave_adapter

Quick setup

Just use 'master_slave_adapter' in your database.yml:

production:
  adapter: master_slave_adapter
  real_adapter: mysql
  master:
    database: app_production
    username: rails
    password: ********
    host: masterdb.example.com
  slave:
    database: app_production
    username: rails
    password: ********
    host: slavedb.example.com

• No matter what, all "write" calls go to the master.
• Inside transactions, all calls go to the master.
• Inside Observers, all calls go to the master.

By default, all other "read" calls will go to the slave, unless you add "default: master" to the options in database.yml.

If you want to control when the slave is used, you can specify which server you want to use (for the 'read' calls) by using:

TheModel.with_master do ... end

TheModel.with_slave do ... end

Credits

A lot of inspiration and understanding of the problem came from Rick Olsen's Masochism.

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Copyright (c) 2009 Sebastian Delmont sd@notso.net Copyright (c) 2009, 2008 StreetEasy / NMD Interactive http://www.streeteasy.com/ All rights reserved.

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