i have created an notification server, which is application specific, now am preparing an application independent server to send notification to the clients using that application for synchronizing purpose, am not asking code and all, will you give me suggestion on this. What is the basic need for an development of application independent component?
Checkout how XMPP works, you will get an idea how can you do the same with Sockets. Try implementing an JSON based XMPP server with nodeJS that works with sockets/webSockets.
Although it is not a push-notification service and more of an XML based messaging protocol. Which is quite similar to the kind of scenario you would want an application independent push notification server for.
The best thing to do is to create a message queue (pub-sub) that different applications can connect to easily.
If your app isn't that big you can create a TCP server and send information to everybody connected. If you need to scale your app you can use something like Redis, ZeroMQ, RabbitMQ etc.
You can checkout my Twitter Steam application to see how I achieve that: