Rails - how can I query the db w/o touching the sessions table

Question

Hi -

I'm trying to provide a HTTP api to my app that queries a db that's read-only (for replication purposes). I find that my app crashes repeatedly when making a request b/c the call is trying to update the sessions table whenever I query the db. This doesn't happen when I return some text without hitting the database for info.

class APIController < AplicationController

  def view
    data = Product.find(params[:id]).to_json # will fail
    data = { :one => 1, :two => 2 }.to_json  # will succeed

    respond_to do |format|
      format.html { render :json => data }
    end
  end  

end

How do I restrict it from touching the sessions table on this request (it's currently issuing an UPDATE on the updated_at field for that session). thanks.

Answer 1

Are you using the session in this request? eg for authentication. That might be a problem.

You can disable the session for controller and/or action:

class MyController < ApplicationController
  session :off, :only => :view

  ...

end

Works a lot like the regular controller filters.

Answer 2

What version of Rails is this? In Rails 2.3, sessions are lazy-loaded, so check in ApplicationController and your plugins for any code (probably in a before_filter) that is accessing any value in your session. You want to avoid that filter for this view action.