Connect-mongo sessions not being deleted automatically

Question

I have an application using NodeJS, Express, MongoDB and connect-mongo.

My issue is that sessions don’t seem to be automatically deleted from MongoDB when they expire, s

Answer 1

You haven't set a clear_interval for your sessions .. the connect-mongo default is -1 (or "never"):

clear_interval Interval in seconds to clear expired sessions (optional, default: -1). Values <= 0 disable expired session clearing.

Example of removing expired sessions every hour (3600s):

var sessionStore = new MongoStore({
     db: 'myappsession',
     clear_interval: 3600
});

You should also make sure you have set a maxAge on your sessions to they actually expire (eg using 1 day):

app.use(express.session({
    secret: "myappsecret",
    cookie: { maxAge: 24 * 60 * 60 * 1000 },
    store:sessionStore
}));