Rails4 Upgrade: Rollback / Downgrade to Rails 3

As with most upgrades / deploy on production, if things go awry, we may have to rollback.

Due to some unexpected behavior, we decided to rollback Rails 4 Upgrade and Boom !! started getting lot of exceptions

NoMethodError: undefined method 'sweep' for Hash

as session cookies blowed up due to different Data Structures in Rails 4 & 3 and not backward-compatible :(

  • Created config/initializers/rails4_to_rails3_downgradability.rb

Enjoy Rails 4 !!!

Written on September 4, 2015