MongoDB mLab mongoose Node.js 驱动程序 - 一段空闲时间后连接超时？

Question

我有一个简单的 Node.js，它使用 mongoose 连接 mLab 上托管的 Mongo 数据库。

一切似乎都很好：添加新记录、查询现有内容。

只是有时，在一段时间不活动后，当我查看控制台时，我会看到以下内容：

events.js:160
      throw er; // Unhandled 'error' event
      ^

Error: connection timeout
    at Db.<anonymous> (___PATH___/node_modules/mongoose/lib/drivers/node-mongodb-native/connection.js:168:17)
    at emitTwo (events.js:106:13)
    at Db.emit (events.js:191:7)
    at Server.listener (___PATH___/node_modules/mongodb/lib/db.js:1786:14)
    at emitOne (events.js:96:13)
    at Server.emit (events.js:188:7)
    at Server.<anonymous> (___PATH___/node_modules/mongodb/lib/server.js:274:14)
    at emitOne (events.js:96:13)
    at Server.emit (events.js:188:7)
    at Pool.<anonymous> (___PATH___/node_modules/mongodb-core/lib/topologies/server.js:334:12)
    at emitOne (events.js:96:13)
    at Pool.emit (events.js:188:7)
    at Connection.<anonymous> (___PATH___/node_modules/mongodb-core/lib/connection/pool.js:270:12)
    at Connection.g (events.js:292:16)
    at emitTwo (events.js:106:13)
    at Connection.emit (events.js:191:7)

现在这对我来说并不重要 - 我总是可以重新启动应用程序。我担心在生产中会引起很多头痛，所以我先发制人地问这里有什么问题？

请注意，最初一切正常，过了一段时间我收到Error: connection timeout

Answer 1

使用 Mongoose 的 Mongo-Node 连接代码示例

var mongoose = require('mongoose');
mongoose.Promise = require('bluebird');

const options = {
    useMongoClient: true,
    reconnectTries: 5000,
    reconnectInterval: 0,
    socketTimeoutMS: 100000,
    connectTimeoutMS: 100000
  }

mongoose.connect(mongodb://........, options);
var db = mongoose.connection;

db.on('error', function (error) {
  console.log('Error while connecting to mongodb database:', error);
});

db.once('open', function () {
  console.log('Successfully connected to mongodb database');
});

db.on('disconnected', function () {
  //Reconnect on timeout
  mongoose.connect(mongodb://........, options);
  db = mongoose.connection;
});

Answer 2

1. 您的互联网连接似乎有波动。这可能是连接超时的原因。
2. 您可以通过设置超时来处理它。

如下：

var timeout = require('connect-timeout');
app.use(timeout('5s'));`

在您的app.js 文件中

Answer 3

用此代码替换您的猫鼬连接设置：

var mongoose = require('mongoose');

/* 
 * Mongoose by default sets the auto_reconnect option to true.
 * We recommend setting socket options at both the server and replica set level.
 * We recommend a 30 second connection timeout because it allows for 
 * plenty of time in most operating environments.
 */
var options = { server: { socketOptions: { keepAlive: 300000, connectTimeoutMS: 30000 } }, 
                replset: { socketOptions: { keepAlive: 300000, connectTimeoutMS : 30000 } } };       

var mongodbUri = 'mongodb://user:pass@host:port/db';

mongoose.connect(mongodbUri, options);
var conn = mongoose.connection;             

conn.on('error', console.error.bind(console, 'connection error:'));  

conn.once('open', function() {
  // Wait for the database connection to establish, then start the app.                         
});