List active user sessions

Hi,

We are using the following to manage sessions using memcache in our ruby app:

use Rack::Session::Memcache, :key => “rack:session”

I want to list the users who are currently logged in. Can you someone tell me how I can the sessions currently active? I could not find anything about it in the documentation.

Also, how do set a “maximum session timeout” for these sessions?

thanks.

-Santosh

anyone any thoughts on this?