TCP socket handling for multiplayer game on NodeJS - node.js

Question

I have a multiplayer game where my server uses nodejs and TCPSocket (net.createServer) to communicate with a client.
I have thousands of clients connecting to the server and many people are complaining that they are constantly being disconnected from the server.
Here is how my server handles the connections now:
Init:
var net = require("net");
server = net.createServer(function(socket) {
socket.setTimeout(15000);
socket.setKeepAlive(true);
socket.myBuffer = "";
socket.msgsQue = [];
socket.on("data", onData);
socket.on("error", onError);
socket.on("end", onClientDisconnect);
socket.on("timeout", onClientDisconnect);
});
server.listen(port);
Sending to client:
var stringData = JSON.stringify({name:event, message:data});
if (!this.socket.msgsQue || typeof this.socket.msgsQue == "undefined")
this.socket.msgsQue = [];
this.socket.msgsQue.unshift(stringData);
var i = this.socket.msgsQue.length;
while(i--) {
if (this.socket.writable) {
var elem = this.socket.msgsQue[i];
this.socket.write(elem+"\0");
this.socket.msgsQue.splice(i, 1);
} else {
//Unable to write at index "i"
break;//will send the rest on the next attempt
}
}
When disconnected
var onClientDisconnect = function() {
this.myBuffer = "";
delete this.myBuffer;
this.msgsQue = [];
delete this.msgsQue;
this.destroy();
}
Receiving from client
var onData = function(data) {
if (!data || !data.toString()) return;
var raw = data.toString();
this.myBuffer += raw;
var d_index = this.myBuffer.indexOf('\0'); // Find the delimiter
// While loop to keep going until no delimiter can be found
var string;
while (d_index > -1) {
// Create string up until the delimiter
string = this.myBuffer.substring(0,d_index);
// Cuts off the processed chunk
this.myBuffer = this.myBuffer.substring(d_index+1);
onMessage(string, this);//handle
// Find the new delimiter
d_index = this.myBuffer.indexOf('\0');
}
}
A problem I notice is that msgsQue becomes huge because the socket is not writable, but disconnect handler is not fired (or hired later..)
Can you give me some advises on how to optimize this ?
I noticed that sometimes I get disconnected, but I can ping the server, so it is definitely a server-related problem. Can it be because of high load on the server itself?
(I do not want to use socket.io because the last year I had many problems with it like memory leaking, freezing the server app, no support, etc..)