Express.js session lost after about 3min - node.js

Question

I use express.js and React. After success login I store user_id in session but after 2-3min session is lost and when I refresh page they log out me.
Here is my server.js
var mysql = require('mysql');
var connection = mysql.createConnection({
host : 'host',
user : 'user',
password : 'password',
database : 'database',
pool : { maxConnections: 50, maxIdleTime: 30},
});
connection.connect(function(error){
if(!!error){
console.log('error');
}else{
console.log('Connected');
}
})
//pluginy
var bodyParser = require('body-parser');
var express = require('express');
var session = require('express-session');
var app = express();
//ustwienia
app.use(bodyParser()); //przesylanie danych w req.body
app.set('trust proxy', 1) // trust first proxy
app.use(session({
secret: 'v8bRRj7XVC6Dvp',
saveUninitialized: true,
resave: true,
cookie: {secure: true}
}));
app.use('/static', express.static(__dirname + '/src'));
app.use('/dist', express.static(__dirname + '/dist'));
app.use('/php', express.static(__dirname + '/php'));
app.set('views', __dirname + '/views');
app.set('view engine','pug');
function checkAuth(req, res, next) {
console.log('User id: '+req.session.user_id);
if (!req.session.user_id) {
if(req.route.path=='/'){
res.render("indexNotLogin",{title:''});
}else{
res.send('You are not authorized to view this page');
}
} else {
next();
}
}
//roots
//index
app.get('/', checkAuth, function(req, res){
res.render("index",{title:''});
})
//funkcje
app.get('/funkcje', function(req, res){
res.render("funkcje",{title:''});
})
//trylogin
app.post('/trylogin', function(req, res){
var username = req.body.name;
var password = req.body.password;
connection.query("SELECT * FROM user WHERE username='"+username+"' AND pass='"+password+"' LIMIT 1", function(error, rows,fields){
//callback
if(!!error){
console.log('error in query');
}else{
if(rows.length){
console.log(rows[0].id)
req.session.user_id = rows[0].id;
res.redirect('/');
}else{
res.send('user dont exist')
}
}
})
})
app.listen(3000,'0.0.0.0', function(){
console.log('Port: 3000')
})
after form submit I do function /trylogin and eveything work fine, req.session.user_id = rows[0].id is user_id, but why session is lost so fast ?

Answer 1

You can increase your session time by using maxAge option in session middleware:
app.use(session({
secret: 'v8bRRj7XVC6Dvp',
saveUninitialized: true,
resave: true,
cookie: {maxAge:900000} //here ,15 min session time
}));

Answer 2

I solved this issue by using express-mysql-session package.
//import
const session = require('express-session');
const MySQLStore = require('express-mysql-session')(session);
let options = {
host: process.env.hostNameDB,
port: 3306,
user: process.env.userNameDB,
password: process.env.passwordDB,
database: process.env.databaseName,
expiration: 1000 * 60 * 60 * 24,
clearExpired: true,
checkExpirationInterval: 1000 * 60 * 60 * 24, //per day db cleaning
};
let sessionStore = new MySQLStore(options);
app.use(session({
key: 'session_cookie_name',
secret: 'session_cookie_secret',
store: sessionStore,
resave: false,
saveUninitialized: false,
}));
By using this package you can store your session data properly and then it will delete the data from DB when checkExpirationInterval is crossed.