[Server-devel] Serving 400+ students w/ a single central XS - ejabberd nightmare?

[Bryan Berry]

On Tue, 2009-03-10 at 09:58 +1300, Martin Langhoff wrote:
> On Mon, Mar 9, 2009 at 12:11 AM, Bryan Berry <bryan at olenepal.org> wrote:
> > I am worried about the XO's and not the XS.
> 
> Now you're starting to see what I've seen :-/ I also worry about your
> APs and networking infra -- to support 400 active users you'll want at
> least 8 APs. In more realistic terms, you'll probably need 12,
> assuming a reasonably balanced load.

We will have roughly 8+ AP's. We have found that off-the-shelf AP's can
handle around 60-70 users.  But that doesn't still doesn't solve the
problem of the XO's getting bogged down by tons of ejabberd chatter.

DSD: do you have any ideas about this?

We are looking at about 100-150 students per school and connecting 3-4
schools to a central XS. 

> As I mentioned before... I am working on xs-0.6, with the
> moodle-ejabberd magic.

That's great, but our pilot starts in a month but that doesn't fit our
timeline. I don't want to send out a completely new, untested XS into
rural parts of Nepal.

Do you have any other suggestions fo us?

> > This dell server has a dual-core Xeon 3.0 GHz processor and 2 GB RAM.
> > RAM was fine, beam only used 450 MB according to ps_mem.py
> 
> Well, that's 1/4 of your RAM. You need to budget for apache/php,
> postgres, and squid. Right now the main problem is Squid.

That was 450 MB during account creation. It dropped significantly
thereafter. I didn't provide much server stats last time because the XS
resource usage isn't a critical problem.

> Thanks for the list below. Quite a few are about stuff I can't help
> with (roof leaks, power cords...) the others, I'm working on...

That's the whole point of why I am telling you about such problems and
how they make a centralized XS easier for us to maintain.


-- 
Bryan W. Berry
Technology Director
OLE Nepal, http://www.olenepal.org