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

2009-03-10 Thread Reuben K. Caron

Daniel Drake wrote:

2009/3/9 Bryan Berry br...@olenepal.org:
  

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?



Have only had a chance to test numbers on Linksys WRT54Gsomething
routers, which stop accepting new connections after 33 users. yay.
  

Have you tried loading a different firmware on these, dd-wrt?
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Re: [Server-devel] Serving 400+ students w/ a single central XS - ejabberd nightmare?

2009-03-10 Thread Rangan Srikhanta
Folks,

 

Here at OLPC AU, we are using Linksys WRT54GLs using DD-WRT and configuring
the routers to act as an AP according to the following instructions.
http://www.dd-wrt.com/wiki/index.php/Wireless_Access_Point 

 

I found I could turn the WRT54GL into the required AP mode in 10minutes,
using an XO. 

 

In our first round of deployments we will be only using WRT54GLs, and after
speaking to Dev, will be working on 1 for every 25. 

 

Thx,

 

Rangan

 

From: server-devel-boun...@lists.laptop.org
[mailto:server-devel-boun...@lists.laptop.org] On Behalf Of Reuben K. Caron
Sent: Tuesday, 10 March 2009 11:29 PM
To: Daniel Drake
Cc: server-devel
Subject: Re: [Server-devel] Serving 400+ students w/ a single central XS -
ejabberd nightmare?

 

Daniel Drake wrote: 

2009/3/9 Bryan Berry  mailto:br...@olenepal.org br...@olenepal.org:
  

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?


 
Have only had a chance to test numbers on Linksys WRT54Gsomething
routers, which stop accepting new connections after 33 users. yay.
  

Have you tried loading a different firmware on these, dd-wrt?

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

2009-03-10 Thread Dev Mohanty
Rangan,

I remember the Linksys routers used to drop connection, as soon as 33-34
clients were logged in, and as Bryan
mentioned we got much better perfomance with the readily available
Taiwanese brand
of APs. With a Linksys 25 odd clients works just fine though with heavy
traffic.

With the Linksys WRT54G /L/S variants, its important to note the version (eg
5.1/ v6/ v8) and chip used (Atheros/ Broadcom) as
only certain versions support full funtionality, with opensourced firware.

Here's a good table to refer to:
http://www.dd-wrt.com/wiki/index.php/Supported_Devices

Cheers,
Dev


On 3/10/09, Rangan Srikhanta ran...@laptop.org.au wrote:

 Folks,



 Here at OLPC AU, we are using Linksys WRT54GLs using DD-WRT and configuring
 the routers to act as an AP according to the following instructions.
 http://www.dd-wrt.com/wiki/index.php/Wireless_Access_Point



 I found I could turn the WRT54GL into the required AP mode in 10minutes,
 using an XO.



 In our first round of deployments we will be only using WRT54GLs, and after
 speaking to Dev, will be working on 1 for every 25.



 Thx,



 Rangan



 *From:* server-devel-boun...@lists.laptop.org [mailto:
 server-devel-boun...@lists.laptop.org] *On Behalf Of *Reuben K. Caron
 *Sent:* Tuesday, 10 March 2009 11:29 PM
 *To:* Daniel Drake
 *Cc:* server-devel
 *Subject:* Re: [Server-devel] Serving 400+ students w/ a single central XS
 - ejabberd nightmare?



 Daniel Drake wrote:

 2009/3/9 Bryan Berry br...@olenepal.org br...@olenepal.org:



 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?





 Have only had a chance to test numbers on Linksys WRT54Gsomething

 routers, which stop accepting new connections after 33 users. yay.



 Have you tried loading a different firmware on these, dd-wrt?

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

2009-03-10 Thread Sameer Verma
On Tue, Mar 10, 2009 at 6:14 AM, Daniel Drake d...@laptop.org wrote:
 2009/3/10 Reuben K. Caron reu...@laptop.org:
 Have you tried loading a different firmware on these, dd-wrt?

 No, but there are regulatory issues there and we won't be using them
 in the schools...only used them because it was the only thing
 available to run tests with.

 The exact model is Linksys WRT54Gv8. You'd think that after 8
 revisions and several years of developing these APs might support 34
 users, WDS, or running as a STA. nope!


There's a reason why Cisco bought them. Upgrade path! Squeeze from
below, pull from above. http://www.linksystocisco.com/

Sameer

 Daniel
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[Server-devel] notes on scaling ejabberd for the XO's

2009-03-10 Thread Bryan Berry
Here are some notes from a short IRC conversation I had w/ Rob Mcqueen,
the lead developer of Telepathy

transcript of conversation on #sugar
bemasc: bernie: I am concerned about the fact that in the default
schoolserver set up all users are in one giant shared roster
Robot101 RESOLVED, ALREADYFIXED (but not in any deployments, or in the
UI)
BryanWB and the resulting chatter slows down the XO/Sugar
considerably?
Robot101 yes
 Robot101 rwh
 the latest versions of sugar and telepathy support using an XMPP
component called gadget
 instead of the shared roster
BryanWB Robot101: so gadget fixes this?
Robot101 yup
 Robot101 rwh
 you only receive push notifications about a) what Sugar has searched
for/displaying on the neighborhood view, or b) your friends
-- hgcphoenix (n=hc...@124.107.253.193) has joined #sugar
BryanWB Robot101: neat, and does it work together w/ the XS? 
 Robot101: which version of sugar is it in?
-- hgcphoenix (n=hc...@124.107.253.193) has left #sugar
Robot101 they went off on a complete tangent trying to hack shared
rosters to have less mutually visible sets of people
 we thought of that but also decided it was the bong, so we fixed it
properly with gadget.
BryanWB Robot101: what is the testing status of gadget?
Robot101 it's deployed on jabber.sugarlabs.org (which is on
collabora.co.uk)
 seems to work fine, ejabberd seems to gradually leak memory though,
which isn't too great
 maybe a little much CPU usage on gadget, but nothing you couldn't
profile
 and I'm not familiar enough with the sugar release cycle to say where
the support went in
 Robot101 rwh
 eu daytime is better to find the Sugar devs and the Collaborans who
worked on Gadget
 (cassidy, daf)
BryanWB Robot101: ok, will talk w/ them later today
Robot101 gadget was always our plan, it just took us a while to get to
it
BryanWB Robot101: by the way last year we tested ejabberd by streaming
your video talk on Telepathy to 80 XO's
bemasc Robot101: I believe martin dropped the shared roster, and
inside is simply using moodle to set all rosters directly.
 s/inside/instead/
 bemasc bernie benzea
Robot101 bemasc: so it's still shared as in server-enforced mutual
visibility, just in smaller groups.
bemasc right, but from ejabberd's perspective, it's individual rosters
Robot101 that's exactly how shared rosters always work
Robot101 the client thread gets a copy of the same roster at sign in
bemasc oh? I thought there was a patch to ejabberd required.
Robot101 yes, he's patched it to source the shared roster from moodle,
I'd imagine
bemasc martin seemed to say that he could use a totally stock ejabberd
Robot101 oh, right. sql query or something. our patches were just
extending the built-in shared roster to a) work properly (deal with
dynamic additions and removals) and b) support a group of online users
rather than everyone


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

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

2009-03-10 Thread John Watlington

If you aren't going to place school servers in the actual schools,  
and insist on
centralizing them, the hardware recommended by Sameer is a good idea.

My argument has always been that you want local web caching and content,
and that an XS shouldn't be that much more expensive than the above  
hardware.
If you are willing to guarantee constant connectivity to a central  
office to support
centralized servers, remotely maintaining the servers in the schools  
shouldn't be a problem.

Cheers,
wad

On Mar 10, 2009, at 1:57 PM, Sameer Verma wrote:

 On Tue, Mar 10, 2009 at 3:12 AM, Bryan Berry br...@olenepal.org  
 wrote:
 On Mon, 2009-03-09 at 21:51 -0700, Sameer Verma wrote:
 On Mon, Mar 9, 2009 at 7:04 PM, Bryan Berry br...@olenepal.org  
 wrote:
 On Tue, 2009-03-10 at 09:58 +1300, Martin Langhoff wrote:
 On Mon, Mar 9, 2009 at 12:11 AM, Bryan Berry  
 br...@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?


 What if you had a small footprint box (like a soekris or  
 routerboard)
 at the school that talks to APs on one end via a switch, and does
 tunneling back to XS in a central location? That way you would  
 have a
 fairly dumb tunnel unit at school (literally plug-and-play) and XS
 management back at your central shop.

 Sameer

 Thanks for the suggestion Sameer.

 I don't really understand what benifits the soekris or routerboard  
 adds
 in this situation? Can u pls explain further?


 The Soekris unit (say Soekris 4501 http://www.soekris.com/net4501.htm)
 would sit at the school location talking to the APs via a switch on
 one end and create a tunnel on the other end to your XS farm. The
 tunnel runs over a VPN from school to XS farm. Both Soekris and
 Routerboard have miniPCI slots that will take hardware accelerators
 for VPN such as this one: http://www.soekris.com/vpn1401.htm so it is
 possible to run VPNs on these boards.

 Soekris units are almost zero maintenance (no moving parts etc.) and
 can also double up as APs. One thing to note: the hw VPN accelerator
 support under Linux isn't very robust. I've used it with BSD
 (http://m0n0.ch/wall/) and it works well. It will do IPSec VPN
 tunnels. http://m0n0.ch/wall/features.php

 With a zero maintenance small footprint unit at the school (will run
 with 12 V as well) and XS units at your school server farm you can
 maintain the XS units locally and keep the school network running via
 the VPN.

 The last time I suggested this, the -1 reasoning was that you would
 need a good connection between the school and the XS farm.
 http://lists.laptop.org/pipermail/server-devel/2008-October/ 
 002244.html

 Sameer
 -- 
 Dr. Sameer Verma, Ph.D.
 Associate Professor of Information Systems
 San Francisco State University
 San Francisco CA 94132 USA
 http://verma.sfsu.edu/
 http://opensource.sfsu.edu/ole-nepal- 
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