How to solve Mongoose v5.11.0 model.find() error: Operation `products.find()` buffering timed out after 10000ms"

Question

How to solve model.find() function produces "buffering timed out after ... ms"? I'm using mongoose v 5.11.0, npm v6.14.8 and mongodb v

Here's the code.

var express = require('express');
var app = express();
var bodyParser = require('body-parser');
const assert = require('assert');

var mongoose = require('mongoose');

try {
    var db = mongoose.connect('mongodb://localhost:27017', {useNewUrlParser: true, dbName: 'swag-shop' });
    console.log('success connection');
}
catch (error) {
    console.log('Error connection: ' + error);
}


var Product = require('./model/product');
var WishList = require('./model/wishlist');

//Allow all requests from all domains & localhost
app.all('/*', function(req, res, next) {
  res.header("Access-Control-Allow-Origin", "*");
  res.header("Access-Control-Allow-Headers", "X-Requested-With, Content-Type, Accept");
  res.header("Access-Control-Allow-Methods", "POST, GET");
  next();
});

app.get('/product', function(request, response) {

    Product.find({},function(err, products) {
        if (err) {
            response.status(500).send({error: "Could not fetch products. "+ err});
        } else {
            response.send(products);
        }
    });
});

app.listen(3004, function() {
    console.log("Swag Shop API running on port 3004...");
});

The product model:

var mongoose = require('mongoose');
var Schema = mongoose.Schema;

var product = new Schema({
    title: String,
    price: Number,
    likes: {type: Number, default: 0}
});

module.exports = mongoose.model('Product', product);

Additionally, running the file also produces the following warnings:

D:\Test\swag-shop-api>nodemon server.js
[nodemon] 2.0.6
[nodemon] to restart at any time, enter `rs`
[nodemon] watching path(s): *.*
[nodemon] watching extensions: js,mjs,json
[nodemon] starting `node server.js`
success connection
Swag Shop API running on port 3004...
(node:28596) UnhandledPromiseRejectionWarning: TypeError [ERR_INVALID_ARG_TYPE]: The "url" argument must be of type string. Received type function ([Function (anonymous)])
    at validateString (internal/validators.js:122:11)
    at Url.parse (url.js:159:3)
    at Object.urlParse [as parse] (url.js:154:13)
    at module.exports (D:\Test\swag-shop-api\node_modules\mongoose\node_modules\mongodb\lib\url_parser.js:15:23)
    at connect (D:\Test\swag-shop-api\node_modules\mongoose\node_modules\mongodb\lib\mongo_client.js:403:16)
    at D:\Test\swag-shop-api\node_modules\mongoose\node_modules\mongodb\lib\mongo_client.js:217:7
    at new Promise (<anonymous>)
    at MongoClient.connect (D:\Test\swag-shop-api\node_modules\mongoose\node_modules\mongodb\lib\mongo_client.js:213:12)
    at D:\Test\swag-shop-api\node_modules\mongoose\lib\connection.js:820:12
    at new Promise (<anonymous>)
    at NativeConnection.Connection.openUri (D:\Test\swag-shop-api\node_modules\mongoose\lib\connection.js:817:19)
    at D:\Test\swag-shop-api\node_modules\mongoose\lib\index.js:345:10
    at D:\Test\swag-shop-api\node_modules\mongoose\lib\helpers\promiseOrCallback.js:31:5
    at new Promise (<anonymous>)
    at promiseOrCallback (D:\Test\swag-shop-api\node_modules\mongoose\lib\helpers\promiseOrCallback.js:30:10)
    at Mongoose._promiseOrCallback (D:\Test\swag-shop-api\node_modules\mongoose\lib\index.js:1135:10)
(Use `node --trace-warnings ...` to show where the warning was created)
(node:28596) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:28596) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

I tried increasing the bufferTimeoutMS or disabling the bufferCommands but still it won't work.

Answer 1

According to Documentation found in this link: https://mongoosejs.com/docs/connections.html#buffering

Mongoose lets you start using your models immediately, without waiting for mongoose to establish a connection to MongoDB.

That's because mongoose buffers model function calls internally. This buffering is convenient, but also a common source of confusion. Mongoose will not throw any errors by default if you use a model without connecting.

TL;DR:

Your model is being called before the connection is established. You need to use async/await with connect() or createConnection(); or use .then(), as these functions return promises now from Mongoose 5.

Answer 2

The issue on model.find() error: Operation products.find() buffering timed out after 10000ms" was resolved by removing the node_module folder, *.json files and reinstalling the mongoose module.

The issue on the warnings was resolved by following this instructions https://mongoosejs.com/docs/deprecations.html

Answer 3

Well, I encountered the same problem and had very similar code. I got the same error when sending a get request while testing.

Eventually, I found the solution that my localhost DB wasn't running at that moment. Though it's a foolish error, but I had a hard time finding it.

Answer 4

This error poped becuase you are trying to access models before creating the connection with the database

Always link your mongodbconnection file (if you have created) in app.js by

 var mongoose = require('./mongoconnection');

or just keep mongodb connection code in app.js