Node.js MySQL connection pool with node-mysql package

db.js

var mysql = require('mysql');

function handleDisconnect(db_config) {
  var connection = mysql.createPool(db_config);

  connection.on('error', function(err) {
    console.error('db error', err, err.code);
    if(err.code === 'PROTOCOL_CONNECTION_LOST') {
      handleDisconnect(db_config);
    } else {
      throw err;
    }
  });
  return connection;
}

var connection = handleDisconnect({
    connectionLimit : 10,
    host:     'localhost',
    user:     'root',
    password: '',
    database: 'test',
    dateStrings: true,
    multipleStatements: true,
    queryFormat: function (query, values) {
      if (!values) return query;
      return query.replace(/\:(\w+)/g, function (txt, key) {
        if (values.hasOwnProperty(key)) {
          return this.escape(values[key]);
        }
        return txt;
      }.bind(this));
    }
});

module.exports = connection;