mongoose to mlab connection issues : UnhandledPromiseRejectionWarning: Unhandled promise rejection

问题

const express = require('express');
const app = express();
const mongoose = require('mongoose');
require('./models/users');
require('./services/passport');
const authRoutes = require('./routes/authRoutes');
const Keys = require('./config/dev');

authRoutes(app);

mongoose.connect(Keys.MONGOOSE_URI);

const port = process.env.PORT || 5000;
app.listen(port);

I have a node express application and I trying to connect to mlab db using mongoose. I am getting following exception:

UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): MongoNetworkError: failed to connect to server [ds111598.mlab.com:11598] otworkError: connect ECONNREFUSED 35.168.9.109:11598]

Tech stack I am using:

"mongoose": "^4.11.1",
node: 6.11.1
npm: 4.6.1

I have tried using the latest mongoose version as well but still the same issue. I am stuck because of this. Can anybody help in this?

Thanks

回答1:

If you are under corporate proxy, you must have to come out else you can check my code.

 const options = {
    useMongoClient: true,
    autoIndex: false, // Don't build indexes
    reconnectTries: 100, // Never stop trying to reconnect
    reconnectInterval: 500, // Reconnect every 500ms
    poolSize: 10, // Maintain up to 10 socket connections
    // If not connected, return errors immediately rather than waiting for reconnect
    bufferMaxEntries: 0
  };
mongoose.connect('mongodb://user:xxxxxx@dsxxxx.mlab.com:667799/DB_NAME',options).then(
  ()=>{
    console.log("connected to mongoDB")},
 (err)=>{
     console.log("err",err);
}

)

回答2:

SOLUTION

I just ran into this same problem, and spent several minutes trying to debug and get a successful workaround.

But very easily I was able to solved it.

The issue for getting authentication error is because one does not have yet created a user on mlab that would be connected to mongo remotely.

Creating a db successfully on mlab is not the last step before reverting back to text editor to connect to mongo via provided url on mlab page.

ONE HAS TO CREATE A USER UNDER 'USERS' tab on mlab which is located on database's details page.

Add the credentials then to create a user, and then finally add these credentials in the mlab-provided mongo url.

And walla! YOU ARE CONNECTED.

回答3:

Create a new User and more importantly, ensure that password for the user contains only Alphanumeric. No special characters like . # , e.t.c

回答4:

I solved this issue by not using a '.' in the db username. This isn't clear but it fixed my issue.

来源：https://stackoverflow.com/questions/48418636/mongoose-to-mlab-connection-issues-unhandledpromiserejectionwarning-unhandled

标签

node.js

mongodb

express

mongoose

mlab