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xmpppushblazeds

Difference among Comet servers and XMPP servers

In my next planned project I suppose to implement an online classroom website in which I want to share a black board (Say a simple text area) among the Tutor and the participating online students {These all are logined through the website}. Whatever the text Tutor writes over the Black board has to be seen by the other participants in Real-time.

I want to use Java as my development platform.

To implement this I started googling on PUSH technology. I read that XMPP implementation servers and XMPP libraries can be used to implement near-realtime applications like collaberative applications/mutiparty games/IM applications etc., But I also read about BlazeDS usage for real-time and low-lattency web applications.

My questions are,

  1. what is the difference among these XMPP java based implementation and BlazeDS? Is not both the techs final goal is to achieve low-lattency web apps using PUSH technology?

  2. What is the difference among Comet servers and XMPP Servers? Do they just differ in the way they implement the PUSH technology or any thing else?

I am confused. Please someone explain me these little more so that I will know what I do before I do the things and where to start on next in my project.

Thanks

Solution

  • To answer your first question: No, XMPP's goal is not simply to "achieve low-latency web apps using PUSH technology". XMPP far pre-dates the "realtime web", and is a much more extensive platform than basic comet/push servers.

    Features in XMPP that won't typically be in plain push servers include:

    • Support for non-web clients (including existing desktop clients)
    • A choice of authentication methods from strong credential-based mechanisms such as SCRAM-SHA-1 to temporary anonymous accounts
    • Support for federation (communication with other XMPP servers)
    • Lots of chat-centric capabilities available (contact lists, offline messaging, file transfers) - this can be a bonus or worthless, but most features like these can be disabled in some XMPP servers.

    If you are just looking for a component to push messages to website visitors in realtime, and you're using Java which BlazeDS integrates tightly with, then BlazeDS is probably your best choice.

    If your push system is part of a larger realtime platform which may involve multiple clients (including non-web for example), multiple languages, and even possibly multiple servers (e.g. you could allow users to use existing XMPP accounts to receive updates) then XMPP is more than likely worth looking into.