In short I want to implement a feature used by gmail where one user can expire or log out all other users on different machines using same user id's.
you can do this by having a table(say login_detail) in server with column:
UserId, ClientSessionValue
When ever user login, store unique cookie(ClientSessionValue) in browser as well as in login_detail table. so if user is going to login from 3 machine, store his id 3 times against the 3 different ClientSessionValue in data base table.
So when ever user want to logout from a machine, delete one row from login_detail of corresponding ClientSessionValue.
When ever any request will come from client it will come with ClientSessionValue cookie. so if this value is not present against that user means, that user is logged out of that machine.
Now, if user want to expire or log out all other login from different machines, just delete all rows except one row from where delete request has come.
Unsolved 
