A simple plugin which adds database mirroring support for Rails MS Sql Server Adapter.

Targets Rails 4.1.x and activerecord-sqlserver-adapter 4.1.0.

Add to the Gemfile:

gem 'tiny_tds'
gem 'activerecord-sqlserver-adapter-mirroring'

Add mirroring section to the database.yml:

development:
  adapter:  sqlserver
  host:     primary
  database: ...
  username: ...
  password: ...
  mirror: 
    host: mirror

When the connection to the primary host fails, adapter will reconnect to the mirror host.

• Create database named activerecord_unittest_mirroring.

• Configure mirroring for that database.

• Create user rails without password, with sysadmin role on both servers. Sysadmin rights are needed because rails user will initiate mirroring failover.

• Ensure that one server responds to the primary hostname, and another to the mirror hostname.

• Run tests

  rake test

You can an edit test/database.yml to define better suited parameters for your system.