// use this middleware to reset cookie expiration time
// when user hit page every time
app.use(function(req, res, next){
req.session._garbage = Date();
req.session.touch();
next();
}); 

app.use(session({
secret: 'test', 
resave: false, 
saveUninitialized: true,
cookie:{
maxAge: 1000*60*60 // default session expiration is set to 1 hour
},
store: new MemcachedStore({
hosts: ['127.0.0.1:9000'],
prefix: 'test_'
})
})); 

Concurrency: 1
none 4484.86 [#/sec] 
memory 2144.15 [#/sec] 
redis 1891.96 [#/sec] 
mongo 710.85 [#/sec] 
Concurrency: 10
none 5737.21 [#/sec] 
memory 3336.45 [#/sec] 
redis 3164.84 [#/sec] 
mongo 1783.65 [#/sec] 
Concurrency: 100
none 5500.41 [#/sec] 
memory 3274.33 [#/sec] 
redis 3269.49 [#/sec] 
mongo 2416.72 [#/sec] 
Concurrency: 500
none 5008.14 [#/sec] 
memory 3137.93 [#/sec] 
redis 3122.37 [#/sec] 
mongo 2258.21 [#/sec]

app.get("/", function(req,res){
if ( req.session && req.session.user_id){
req.session.no = req.session.user_id;
} else {
throw Error('error');
}
res.send("No: " + req.session.no);});

app.use(express.session({
store: new RedisStore({
host: 'localhost',
port: 6379,
db: 2,
}),
secret: 'hello'}));

app.use(express.cookieParser());app.use(express.session({
store: new MongoStore({
url: 'mongodb://localhost/test-session'
}),
secret: 'hello'}));