Mongoose Trying to open unclosed connection - node.js

Question

This is a simplified version of the problem, but basically I'm trying to open 2 mongodb connections with mongoose and it's giving me "Trying to open unclosed connection." error.
Code sample:
var db1 = require('mongoose');
db1.connect('my.db.ip.address', 'my-db');
var db2 = require('mongoose');
db2.connect('my.db.ip.address', 'my-db');
db2.connection.close();
db1.connection.close();
Any idea how to make it work?

Answer 1

connect() opens the default connection to the db. Since you want two different connections, use createConnection().
API link: http://mongoosejs.com/docs/api.html#index_Mongoose-createConnection

Answer 2

To add on Raghuveer answer :
I would also mention that instead of using mongoose directly (you are probably using it this way you end up on this post) :
require('mongoose').model(...);
You would use the returned connection :
var db = require('mongoose').connect('xxx', 'yyy');
db.model(...);

Answer 3

I get this issue while running my tests.
This is what I did to solve it.
//- in my app.js file.
try {
mongoose.connect('mongodb://localhost/userApi2'); //- starting a db connection
}catch(err) {
mongoose.createConnection('mongodb://localhost/userApi2'); //- starting another db connection
}

Answer 4

I had this problem doing unit test with mocha.
The problem came when I added a second test because beforeEach is called twice.
I've solved this with this code:
const mongoose = require('mongoose');
describe('Your test suite', () => {
beforeEach( () => {
if (mongoose.connection.db) {
return; // or done();
} else {
// connect to mongodb
});
describe('GET /some-path', () => {
it('It should...', () => {
});
});
describe('POST /some-path', () => {
it('It should...', () => {
});
});
});
Hope it helps you!

Answer 5

You are attempting to open the default connection ( which is not yet closed ) a 2nd time.
do the following instead
var db = require('mongoose'); //note only one 'require' needed.
var connectionToDb1 = db.createConnection('my.db1.ip.address', 'my-db1');
var connectionToDb2 = db.createConnection('my.db2.ip.address', 'my-db2');

Answer 6

Using mongoose.disconnect(fn):
mongoose.disconnect(() => {
// here it would be possible "reset" models to fix
// OverwriteModelError errors
mongoose.models = {};
// here comes your logic like registering Hapi plugins
server.register(somePlugin, callback);
});
I found this question typing the error message and despite my problem is a bit different I believe it could be useful for those using Hapi. More specifically Hapi + rest-hapi + mocha.
When running mocha with --watch option I was facing both: OverwriteModelError and Error: Trying to open unclosed connection errors.

Answer 7

Simple Solution -
Use mongoose.createConnection() instead of mongoose.connect()
Its occurs because of version issue