RJ wrote:
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of
Bill de hOra
Sent: 26 February 2009 09:56
To: XMPP and Social Networking, Two Great Tastes That Taste Great Together!
Subject: Re: [Social] Facebook and XMPP?
<snip>
I don't agree with the transport point - XMPP works at a higher level on
the stack. I think in many cases the requirement is to distribute lots
of packets to a lot of people. Distributing the same packet to a lot of
people sounds like pub/sub, which I'm fairly sure remains a challenge at
the scales we're talking about.
</snip>
I can't agree with that - I think the kind of people who might consider deploying a >>1M
user XMPP system would have no problem knocking together a custom pubsub system of the
same magnitude. I wrote a simple pubsub system using COMET/http and tested with 1M users;
it will run on less than $10k worth of hardware, which isn't unreasonable.
And I think this works because even though a comet clients hit a server
hard, you can leverage commodity web infrastructure. Plus comet clients
will drop and reconnect. Web load balancing technology (which is what
anything doing "social networking" is building on) afaict isn't geared
up for handling a lot of long lived connections - this makes
abstracting away your cluster from clients tougher. [BIG-IP LTM has a
voip extension, that makes me think XMPP can eventually have commodity
load balancing.]
What happens if you're running an XMPP server and you suddenly have massive
uptake?
You have to figure out a lot more on your own. For this reason, I worry that
the facebooks
of the world would prefer to build their own xmpp server rather than use
existing ones.
It's fun to build, and you'll have experts on hand. Livejournal did it with
djabberd.
Doesn't help the rest of us tho, because these implementations are rarely
published, and
if they are, usually without any decent documentation or community.
I think they'll be happy to use XMPP internally and for S2S. It's
supporting a lot of XMPP clients on the front end that's challenging.
Bill
