Rails sessions not saving

问题:

I'm in the process of upgrading a Rails app from Rails 2 directly to Rails 4. I'm using the new /config/initializers/session_store.rb file, with CookieStore, but for some reason my sessions are not saving.

When trying to do something along the lines of render :text => "#{request.session_options[:id]}" I get a new session ID every refresh.

I've tried on different browsers, and all should be accepting cookies.

I have no idea what's going on. Why won't these sessions persist?!

Edit: thank you all for your suggestions. Here's a little more information, and a few things I've noticed:

• First, about my set up -- I'm running the server with Rails 4/Ruby 2 through RVM on an Ubuntu VM on my Windows 7 machine.
• Although I'm upgrading from Rails 2, that only really applies to the models/controllers/views/etc -- I generated a new Rails 4 application for all of the supporting infrastructure.
• I created another application on the same VM that JUST sets a session and then displays, and that works fine.
• What the session is storing varies slightly depending on what the user is doing, but usually it holds simply a user id (just an integer), and occasionally a little more -- (i first noticed this manifesting itself while trying to pass an OAuth token from the OAuth gem.)
• I've noticed that if the VM's system clock falls behind the Windows 7 host machine clock, the user id sessions hold. That causes other problems, especially with OAuth, but there seems to just be a time issue somewhere. I've tried doing things like removing the time zone from my environments/development.rb, but that did not help.

回答1:

As a general answer a couple of possible problems are

• Session size over 4K limit (which is apparently the case).

  CookieOverflow is raised if you attempt to store more than 4K of data.

Please, bear in mind that if you store an object in session, the object is previously serialized before storing it and its size would be bigger. More info on the general problem and possible solutions for the specific problem, here.

• Problems with CSRF protection.

  If the security token doesn't match what was expected, the session will be reset

Edit: To check if it is a CSRF case, you can, as Abdo comments below, temporarily disable the protect_from_forgery line in ApplicationController

回答2:

I had a similar symptoms. It turns out it was because I added the rails-api gem and it totally broke session saving.

回答3:

From: Railscasts Episode 415 Upgrading to Rails 4

There’s one more configuration change we need to make, in the secret token initializer. In Rails 4 the configuration option in this file has been renamed from secret_token to secret_key_base. We’ll need to specify both options while we’re transitioning from Rails 3 but once we’ve successfully migrated our application we can remove the secret_token option. It’s best to use a different token for our secret_key_base.

This is necessary because we’re moving from a serialized cookie stored on the client to an encrypted cookie. This prevents users from easily being able to see the contents of their session cookies.

The episode includes a very good series of tips regarding upgrading from 2 to 4 and I was able to do that successfully using this tutorial.