node js express server using mysql hangs up, how to restart automatically?

Question

I want to have a server running to make some entries in a database. I havent done that before. Im using node.js, express for the server and mysql with node-mysql and host it on uberspace as a low-cost webhosting service. When im starting the server with 'nohup node app.js &' everything seems to work fine, but after some time, I dont get any response from the server in a webbrowser anymore. I think the server just hang up and I want to restart it automatically. Here the simple code for my app.js:

var express = require('express');
var app = express();
var mysql = require('mysql');
var connection = mysql.createConnection({
    host    : '***',
    database: '***',
    user    : '***',
    password: '***',
    port: 3306
});
connection.connect(function(err) {
    console.log(err);
});


app.get('/test', function(req,res) {
    var post = {ID: 1, User: "testuser"};
    var query = connection.query('INSERT INTO testtabelle123 SET ?', post, function(err, results){
        console.log(err);
    });
    console.log(query.sql);
    res.send(query.sql);
});

I guess I simply just have to make a little change for automatically restart in the code and maybe use some sort of middleware/tool for that. Can you tell me what to do? Havent found simple solutions on SO so far.

Answer 1

Problem occurs because mysql is closing connection when there is no connection (after sometime). Add this to make connection alive forever:

setInterval(function () {
    connection.query('SELECT 1', [], function () {})
}, 5000)

Relevant issue: https://github.com/felixge/node-mysql/issues/1337