Moving Back From ActiveRecord Session Store to cookie

A couple months ago I moved from storing sessions in the default cookie store to active_record. Now I kind of want to move back because I am not sure I see any benefit of it but many negatives i.e. it is not easy on my over taxed DB server as is.

The problem is that I thought it was going to be as easy as just flipping the switch back. But it seems to not be that simple. Once I flipped the switch I started getting InvalidAuthenticityToken errors on pretty much every single form on the site. Before hand I never really got these errors (but I did sometimes, anyone know why sometimes they would appear and not other times on the same form) and now I am getting them? How would you cleanly move back from active_record store to cookie?

I really appreciate everyone’s input.

You have to:
1) in application.rb, comment :secret => ..., so you just leave
"protect_from_forgery" uncommented
2) in config/environment.rb, uncomment (or put back)
config.action_controller.session = { ... }

And you're all set.