Mongoose doesn't create new collection

The reason is, mongoose only auto-creates collections on startup that have indexes in them. Your User collection has a unique index in it, the Job collection does not. I've just had the same problem today.

// example code to test
var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/test');

mongoose.model('Test', {
    author: {
    type: String,
    index: true
    }
});

Mongoose won't create the jobs collection for the model until the first document of that model is saved.

Job.create({category: 1, title: 'Minion"}, function(err, doc) {
    // At this point the jobs collection is created.
});

First thing to consider is if you have set the autoIndex property on your connection String to True/False;

By default autoIndex property is set to True, mongoose will automatically build indexes defined in your schema when it connects. This is great for development, but not ideal for large production deployments, because index builds can cause performance degradation. If this is the case and collections are still not being created in your database the problem might be something else and not related with indexes.

If you have set autoIndex to false, mongoose will not automatically build indexes for any model associated with this connection i.e. it will not create the collections. In such scenarios you have to manually call model.ensureIndexes(); usually people call this at the same place where they define the models or inside their controllers which in my opinion is bad for production as it does the same thing autoIndex true except this time we are doing it explicitly.

What i recommend is creating a separate node.js process to run ensureIndexes on explicitly and separate it from our main application node.js process.

The first advantage of this approach is i can choose to which models i want to run ensureIndexes() and the second one it doesn't run on startup of the application and degrade my application performance rather i run it on demand.

Below is sample of the code i use to run ensureIndexes on demand.

import mongoose from 'mongoose';
var readline =  require('readline');

//importing models i want 

import category from '../V1/category/model';
import company from '../V1/company/model';
import country from '../V1/country/model';
import item from '../V1/item/model';


//Connection string options

let options = {useMongoClient:true,
autoIndex:false, autoReconnect:true, promiseLibrary:global.Promise};  

//connecting
let dbConnection = mongoose.createConnection('mongodb://localhost:1298/testDB', options);

 //connection is open
 dbConnection.once('open', function () {

        dbConnection.modelNames()
                    .forEach(name => {
            console.log(`model name ${name}`);                                        
            dbConnection.model(name).ensureIndexes((err)=> {
                if(err) throw new Error(err);              
            });

            dbConnection.model(name).on('index',function(err){                
                if (err) throw new Error(err); 
            });                                      
        });

        console.log("****** Index Creation was Successful *******");
        var rl = readline.createInterface({input:process.stdin,output:process.stdout});        
        rl.question("Press any key to close",function(answer){
            process.exit(0);
        });                                   
    });