版本:
Node JS:7.2.1
Express:4.15.3
MySQL NPM:2.14.1
套接字IO:2.1.1
我们刚刚在应用程序中引入了套接字,以尝试运行通知。但是从那以后,我的数据库就无法连接了。
我一直收到PROTOCOL_CONNECTION_LOST : Connection lost: The server closed the connection.
错误。我已经尝试过this和this。他们似乎没有工作。
第一次没有建立连接,但是如果我在错误事件上设置了InterInterval并在一段时间后尝试重新连接,它确实会连接..但是有些情况下不使用新的连接对象。
我切换了我的分支。连接正常进行。还有其他团队成员同时工作,他们的连接没有任何问题。因此,我猜测这与我实施通知的方式有关。
以下是我的文件:
// socket.js
import server from './../../server.js';
import SocketIO from "socket.io";
import nconf from "nconf";
import eventService from "../../events/service.js";
module.exports.initSocket = (IO) => {
let event = eventService(IO);
let notificationEmissionInterval = nconf.get('NOTIFICATION_INTERVAL_MILLISECONDS');
IO.on("connection", (socket) => {
setInterval(() => {
event.emitNotifications(socket);
}, notificationEmissionInterval);
});
};
if (server) {
let IO = new SocketIO(server);
module.exports.initSocket(IO);
}
// service.js
import path from 'path';
import logger from '../config/lib/logger.js';
import notificationController from "../module/notification/controller/notification.controller.js";
module.exports = (IO) => {
let emitNotifications = (socket) => {
notificationController.getUnreadNotifications(params)
.then((notifications) => {
//Do something
)
};
return {
emitNotifications: emitNotifications,
}
};
// Model.js
import connection from '../../../config/lib/db.js';
import logger from 'logger';
import Promise from 'bluebird';
class NotificationModel {
getUnreadNotifications = () => {
return new Promise((resolve, reject) => {
let query = `CALL GetUnreadNotification()`;
connection.query(query, (err, result) => {
if (err) {
logger.error('Sql error in NotificationModel.getUnreadNotifications : ', err);
reject(err);
}
else {
logger.info('Unread notifications fetched successfully');
resolve(result);
}
});
});
};
}
export default new NotificationModel();
我的数据库文件当前(经过大量调试)如下所示。在通知模型中从导入中注释掉此文件可解决该错误。
// db.js
import mysql from 'mysql';
import nconf from 'nconf';
import logger from './logger.js';
import path from 'path';
nconf.argv()
.env()
.file({
file: path.resolve('./config.json')
});
let dbConfig = {
"host": nconf.get('MYSQL_HOST'),
"port": nconf.get('MYSQL_PORT'),
"user": nconf.get('MYSQL_USER'),
"password": nconf.get('MYSQL_PASSWORD'),
"database": nconf.get('MYSQL_DATABASE'),
"stringifyObjects":true,
"multipleStatements": true,
"dateStrings" : 'DATETIME',
"connectTimeout" : 60000
};
function connectToDatabase() {
logger.info('Trying to connect to the database');
let _conn = mysql.createConnection(dbConfig);
_conn.connect((err) => {
if (err) {
logger.error('Error connecting to the database');
logger.debug(err.code + ' : ' + err.message);
setTimeout(connectToDatabase, 3000);
}
else {
logger.info('Connected to the database via threadId : ' + _conn.threadId);
return _conn;
}
});
_conn.on('error', (err) => {
logger.error('Error connecting to the database');
logger.debug(err.code + ' : ' + err.message);
setTimeout(connectToDatabase, 3000);
});
}
let connection = connectToDatabase();
export default connection;
感谢您的帮助。
答案 0 :(得分:0)
回答我自己的问题。.我使用连接池解决了..
// db.js
__NEXT_DATA__
答案 1 :(得分:0)
您还可以在代码中使用pm2,它们可以轻松解决此问题。
在终端机/外壳中使用此命令
var myItems = App.ls.getSubscriptions()[6].getItems();
var myFields = App.ls.getSubscriptions()[6].getFields();
var adaptername = App.ls.getSubscriptions()[6].getDataAdapter();
var myEH3 = function ff(msg) {
console.log('message received.');
};
var mySub = new Subscription("MERGE", myItems, myFields);
mySub.setDataAdapter(adaptername);
mySub.setRequestedSnapshot("yes");
mySub.addListener({onItemUpdate: myEH3});
App.ls.subscribe(mySub);
修改生态系统文件以符合您的需求
将pm2添加为项目的依赖项
pm2 init //they provide you ecosystem.config.js
在package.json中,修改您的启动脚本。
类似于以下内容。
npm install pm2 or yarn add pm2
最后
{
"scripts": {
"start": "pm2-runtime start ecosystem.config.js --env production"
}
}