migrating_to_rails3.txt

MIGRATING TO RAILS 3 - AN IN-HOUSE DEVELOPER'S PERSPECTIVE

Only migrate apps when there is a change request.  Unchanged apps stay in old versions of Rails.

5 common problem areas:
  1. Creating New Apps
    Rails app templates are helpful
  2. Background Jobs - 2 types:
    * Scheduled Jobs
    * Constantly running to process pending requests
  3. Data Sharing
    * Topic Subscriber approach
    * sharing dbs b/t multiple apps:
      * allow reading from either apps
      * only one app can write
      * if app doesn't own db, it uses resources to have the app owner make the write
      * use abstact classes to read from db that isn't the main app connection db
      * use mysql replication to avoid hitting transaction db for read-only apps
  4. Authentication
    * single sign-on is important so you can switch b/t apps
      * legacy way:  set a domain level cookie that all apps can set/get
      * new way: Rails as master, support legacy apps, support 3rd party apps
        * use devise and omniauth with OAuth2
        * single sign-on AND single logout (by expiring domain cookie)
  5. App Configuration
    * DRY principles for common config settings across all apps