-----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. I agree that it is far harder to find help and resources online about scaling XMPP. If my small website gets popular, there are lots of good presentations and examples explaining the tools and techniques needed to scale up and out (memcached, load balancers, scaling databases, sharding and partitioning, CDNs etc). 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. RJ
