# Session madness \*argh\* **URL:** \ **Category:** Rails\ **Created:** [May 23, 2008, 3:58pm UTC](https://www.ruby-forum.com/t/session-madness-argh/138486 "2008-05-23T15:58:25Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![michael\_teter](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e47c2d/32.png) [@michael\_teter](https://www.ruby-forum.com/u/michael_teter)\ **Post date:** [May 23, 2008, 3:58pm UTC](https://www.ruby-forum.com/t/session-madness-argh/138486/1 "2008-05-23T15:58:25Z")
Environment: Rails 2.0.2; cookie-based sessions (as far as I know… I added the two appropriate lines to environment.rb) Problem: I’m getting inconsistent results storing things in the session. For example, I create a data structure like this: people = [[“bob”,133] [“joe”,145]] Then I set session[:people] = people I’ve got sections of my current page with some JavaScript elements (YUI DataTables) that, based on some user actions, generate new requests to my controller. In my actions in the controller, I’m expecting session[:people] to be valid (because I initialized it with people as described above). However, I’m seeing inconsistent behaviors with that session. Some data is persisting from one call to the next, but others are not. My session itself isn’t being cleared or reset, because if it were I’d lose my “authentication” and be redirected to my login page. Any suggestions? ---
**Author:** ![michael\_teter](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e47c2d/32.png) [@michael\_teter](https://www.ruby-forum.com/u/michael_teter)\ **Post date:** [May 23, 2008, 4:03pm UTC](https://www.ruby-forum.com/t/session-madness-argh/138486/2 "2008-05-23T16:03:46Z")
On 23 May 2008, at 14:57, michael\_teter wrote: > Then I set session[:people] = people > > I’ve got sections of my current page with some JavaScript elements > (YUI DataTables) that, based on some user actions, generate new > requests to my controller. Do you ever have concurrent requests? The following can happen request 1 loads session request 2 loads session request 2 sets session[:people] request 2 saves session (ie sends the cookie back to the user in the case of the session store request 1 saves session Request 1 never knew about the changes made by request 2 and will happily stomp all over the changes made by request 2. I wrote this up in more detail a while ago ([钛刻专家——官网](http://www.texperts.com/2007/05/01/race-conditions-in-rails-sessions-and-how-to-fix-them/) ) Fred ---
**Author:** ![michael\_teter](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e47c2d/32.png) [@michael\_teter](https://www.ruby-forum.com/u/michael_teter)\ **Post date:** [May 23, 2008, 4:24pm UTC](https://www.ruby-forum.com/t/session-madness-argh/138486/3 "2008-05-23T16:24:21Z")
Oh wow, I didn’t realize that’s how it would work underneath. That could be my problem. My page is creating a dozen divs, each of which contains a YUI DataTable, and each of which makes its own (concurrent) request to the controller for data (which I’m rendering out as XML to feed into the DataTable). It’s not my choice to make something this complex, but that aspect is beyond my control. There are multiple requests to my controller-\>action going on. Forgive my confusion here, but my prior experience is with Java (Servlet/JSP) sessions. My assumption here was that by saying session[:something] = x, that would go into memory on the server and persist until I explicitly reset the session or some session timeout occurred. My Googling on Rails sessions hasn’t led me to what I feel is a complete, definitive document on the subject. I’d love if someone had a good reference for me. Thanks, Michael On May 23, 9:02 am, Frederick C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![michael\_teter](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/e47c2d/32.png) [@michael\_teter](https://www.ruby-forum.com/u/michael_teter)\ **Post date:** [May 23, 2008, 4:54pm UTC](https://www.ruby-forum.com/t/session-madness-argh/138486/4 "2008-05-23T16:54:16Z")
On 23 May 2008, at 15:23, michael\_teter wrote: > Oh wow, I didn’t realize that’s how it would work underneath. That > could be my problem. > > My page is creating a dozen divs, each of which contains a YUI > DataTable, and each of which makes its own (concurrent) request to the > controller for data (which I’m rendering out as XML to feed into the > DataTable). It’s not my choice to make something this complex, but > that aspect is beyond my control. Sounds like it could be your problem. > There are multiple requests to my controller-\>action going on. > > Forgive my confusion here, but my prior experience is with Java > (Servlet/JSP) sessions. My assumption here was that by saying > session[:something] = x, that would go into memory on the server and > persist until I explicitly reset the session or some session timeout > occurred. My Googling on Rails sessions hasn’t led me to what I feel > is a complete, definitive document on the subject. I’d love if > someone had a good reference for me. There are several session stores in rails, the default is the cookie store. With all the other stores, your session cookie just contains some unique identifier which enables rails to locate the correct file/ database row/ memcache entry etc… With the cookie store the entirety of the session is stored in the cookie. But apart from that what you say about sessions is basically true. What is unfortunate is the behaviour when there are multiple requests from the same user. the situation could probably be improved creating sessions on demand and only writing them back if the session has changed (there’s a ticket proposing this and other changes be made [http://rails.lighthouseapp.com/projects/8994/tickets/92-feature-more-efficient-session-handling](http://rails.lighthouseapp.com/projects/8994/tickets/92-feature-more-efficient-session-handling) ) Fred