Hi Jason, everyone,
Jason Salas (mobile) a écrit :
Hi Bill/all,
I think in all fairness in regards to load balancing XMPP traffic, most of the strategies to date are custom-built and not formally spec'ed out or officially documented (if I'm in error, somone please point it out). Mickael's company does such custom solutions for enterprise-level IM apps.
A roadblock I'm running into in getting local telecomm carriers and cable providers (in Guam) to warm up to XMPP systems is getting them to stop thinking of network management in terms of web servers. Push/presence/rosters/PubSub is a completely different animal than http, as you effectively pointed out.
The challenges are different, so I'm with you that in lieu of a model for load
balancing we get some case studies. Blaine from Twitter's told me that
clustering should happen at around the 5,000-user level in rosters, at the
latest.
I also foresee the web community crying out for BOSH, as they become more and more aware of it, to include some sort of XMPP variant of a web caching facility, if applicable. Good point made about this here: http://mail.jabber.org/pipermail/bosh/2008-July/000013.html
This further proves your point about a different platform with different mechanics to achieve a common goal.
Jas
As Bill and yourself highlight, PubSub is a different beast but so are
many of other XMPP extensions. Unfortunately for now each XMPP sever
implementation can be seen as a large box where every extensions are
treated the same when many would require different dispatch/storage
strategies. IM is rather straightforward in this regards and has been
efficient for sometime in all implementations but, if we take PubSub,
most are doing rather poorly (both on the way the respect the
specification and their internal algorithms). Is it an issue with the
protocol or with implementations? I have a feeling there is a bit of both.
Today, I would feel more confident about leveraging AtomPub to perform
PubSb operations than the PubSub protocol itself. I'm not downplaying
the spec and I'm really excited about it but it's been so far a
frustrating experience.
- Sylvain
