node.js - Express and Redis - If session exists for this user, don't allow access -

i using redis , express this:

// app.js var redis         = require('redis'),     redisclient   = redis.createclient(),     session       = require('express-session'),     redisstore    = require('connect-redis')(session);  session = session({   store: new redisstore({client: redisclient}),    secret: 'secretkey',   resave: true,   saveuninitialized: true }) 

app.use(session);

in index route file, set user session this:

req.session.user = user; 

when user comes (or opens tab), how detect how many sessions having , block him access if has 1 active session?

express-session working via cookies. had cookie named session sessionid. tabs inside browsed share cookies , can't rely on cookies if want strict working via 1 browser tab.

you need create own sessions each opened browser tab. generating tabid @ client side , saving {userid, tabid} redis

or can use websockets (http://socket.io/) that, little overhead, doing want