Error: connection timeout - expressjs mongodb mongoose - mongodb

Question

I'm new to express/node and web programming in general. What is the best way to deal with this error when mongoose's mongodb connection times out, this is how I connect:
mongoose.connect(config.mongoUrl);
const db = mongoose.connection;
db.on('error', console.error.bind(console, 'error connecting with mongodb database:'));
db.once('open', function() {
console.log('connected to mongodb database');
});
This is the error when it times out while my server is running:
error connecting with mongodb database: Error: connection timeout
at Db. (C:\Users\Sean\OneDrive\webpages\000\lasttry\node_modules\mongoose\lib\drivers\node-mongodb-native\connection.js:169:17)
at emitTwo (events.js:106:13)
at Db.emit (events.js:191:7)
at Server.listener (C:\Users\Sean\OneDrive\webpages\000\lasttry\node_modules\mongodb\lib\db.js:1798:14)
at emitOne (events.js:96:13)
at Server.emit (events.js:188:7)
at Server. (C:\Users\Sean\OneDrive\webpages\000\lasttry\node_modules\mongodb\lib\server.js:274:14)
at emitOne (events.js:96:13)
at Server.emit (events.js:188:7)
at Pool. (C:\Users\Sean\OneDrive\webpages\000\lasttry\node_modules\mongodb-core\lib\topologies\server.js:335:12)
at emitOne (events.js:96:13)
at Pool.emit (events.js:188:7)
at Connection. (C:\Users\Sean\OneDrive\webpages\000\lasttry\node_modules\mongodb-core\lib\connection\pool.js:270:12)
at Connection.g (events.js:291:16)
at emitTwo (events.js:106:13)
at Connection.emit (events.js:191:7)

Answer 1

How about on disconnect just reconnect to mongo. See below:
mongoose.connect(config.mongoUrl);
var db = mongoose.connection;
db.on('error', console.error.bind(console, 'error connecting with mongodb database:'));
db.once('open', function() {
console.log('connected to mongodb database');
});
db.on('disconnected', function () {
//Reconnect on timeout
mongoose.connect(config.mongoUrl);
db = mongoose.connection;
});
You can also set a timeout value on the connection.
mongoose.connect(url, { server: { socketOptions: { connectTimeoutMS: 1000 }}}, function(err) { ... });
Also, make sure that mongo is still running on your machine. A connection timeout could mean mongo isn't running.
Reference: Another stack overflow question

Answer 2

Check mongod is running.
typing mongo in shell.
Add connectTimeoutMS=300000 paramter for you uri.
uri looks like mongodb://localhost/collectionName?connectTimeoutMS=300000