最近线上的进程总是自己挂掉，查看nohup.out文件，发现是mysql链接久了，超时自动关闭链接了，网上搜索了一些解决办法，可依然没有解决。求大神帮忙，谢啦！

Error: Connection lost: The server closed the connection.

下面是我的代码：

var mq = require("mysql");
global.mc = mq.createConnection({
        host:"192.168.1.113",
        user: "root",
        password: "root"
    });
var connectionState = false;
function connectMySql(){
    mc.connect(function(err){
        if(err){
            console.log('SQL connect err:'+err);
            connectionState = false;
        }
        else{
            console.log('SQL connect successful!');
            connectionState = true;
        }
    });
    mc.on('close', function (err) {
        logger.error('mysqldb conn close');
        connectionState = false;
    });
    mc.on('error', function (err) {
        logger.error('mysqldb error: ' + err);
        connectionState = false;
    });
}
connectMySql();
var dbConnChecker = setInterval(function(){
    if(!connectionState){
        connectMySql();
    }
},500);