Nodejs, mysql {[error: connection lost: the server closed the connection.]

when I type localhost:3000

after 20~30 seconds , error

error console: {[error: connection lost: the server closed the connection.] falta: true, code: 'PROTOCOL_CONNECTION_LOST'}

my code

var express = require('express');
var mysql = require('mysql');
var app = express();

var pool      =    mysql.createPool({
    connectionLimit : 2, //important
    host: 'xxxxx',
    user: 'xxxxx',
    password: 'xxx',
    database: 'xxxx',
    debug    :  false
});

pool.on('connection', function(c) {
   console.log('connection');
});

pool.on('enqueue', function () {
    console.log('Waiting for available connection slot');
});



function handle_database(req,res) {

    pool.getConnection(function (err, connection) {


        if(err) {
            console.log(err);
        }

        connection.query( 'SELECT * FROM clientes limit 20', function(err, rows) {

            if(err) {
                console.log(err);
            }

            connection.release();

            res.json(rows);
            res.end();
        });

        connection.on('error', function(err) {
           console.log(err);
        });
    });
}

app.get("/",function(req,res){
    handle_database(req,res);
});

app.listen(3000);

please help? am newbie with node

dependencies

{
  "name": "ChatSuporte",
  "version": "0.0.1",
  "description": "Chat para suporte",
  "dependencies": {
    "express": "^4.12.3",
    "mysql": "^2.6.1"
  }
}