MongoDB: Waiting for available socket hanging - node.js

Question

So I am using Mongoose's findOneAndUpdate to update a key value in a document. I am needing to increment that number by one. If it's not in there it should create a new document. It's in a post route in Node.
I have information going to the post route on a button click. My app requires users to click a button multiple times in succession and i'm getting a Waiting for available sockets... at the bottom of my browser and everything hangs.
I am just doing this on my localhost. At the end of the request once everything "unhangs" I get the following error in my console:
POST http://localhost:3000/api/songsqueued net::ERR_EMPTY_RESPONSE
This is the post route i'm working with:
router.post('/api/songsqueued', function(req, res){
Song.findOneAndUpdate({songId: req.body.songId}, { $inc:{queueTimes: 1} },
function(err, song){
if (err) {
return console.log("Error: " + err)
}
if(song){
song.queueTimes += 1;
song.save(function(err){
if(err){
console.log(err)
} else {
console.log("updated fam")
}
});
} else {
var song = new Song();
song.artistName = req.body.artistName;
song.titleName = req.body.titleName;
song.songId = req.body.songId;
song.songImg = req.body.songImg;
song.save(function(err) {
if (err) {
console.log("Error: " + err)
} else {
console.log("created fam")
}
})
console.log(song);
return res.json({message: "SongCreated"})
}
})
})
Any ideas on how to remedy this?

Answer 1

Your node server needs to send a response to the client in order for the response to complete. If you don't send a response, the connection will timeout and you get the socket hangup. Make sure that you send a response for each condition:
if (err) {
return res.status(500).end("some error message");
}
else if (song) {
return res.status(200).end("updated");
}
else {
return res.status(201).end("created");
}