Re: [Server-devel] Almost-released: XS-0.5.2 -

[Sameer Verma]

On Fri, Mar 6, 2009 at 3:39 AM, Martin Langhoff
 wrote:
> In http://xs-dev.laptop.org/xs/other/ we have the build that I want to
> bless as XS-0.5.2 . I am giving it a quick test -- but it's 11.30pm on
> the Friday (nz time) and it's unlikely that I'll test it enough to be
> happy to name it the official XS-0.5.2 .  To complicate things, this
> weekend and coming week I'll be mostly away from the office for
> personal reasons.
>
> Even then -- it seems to be the best XS we had so far :-)
>
>  $ sha1sum OLPC-School-Server-0.5.2-i386.iso
>  01498d3ddbe19e26d3b4308c8729b828e455255c  OLPC-School-Server-0.5.2-i386.iso
>
> Once I am happy with it -- for example, because I got nice success
> reports from *you* -- we'll declare it official.
>
> cheers,
>
>
> m
> --
>  martin.langh...@gmail.com
>  mar...@laptop.org -- School Server Architect
>  - ask interesting questions
>  - don't get distracted with shiny stuff  - working code first
>  - http://wiki.laptop.org/go/User:Martinlanghoff
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Installs correctly on my Fujitsu P2120 laptop this time around! None
of the failure with yum, etc. Will test some more and write back.

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

[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   
> wrote:
>> On Mon, 2009-03-09 at 21:51 -0700, Sameer Verma wrote:
>>> On Mon, Mar 9, 2009 at 7:04 PM, Bryan Berry   
>>> wrote:
 On Tue, 2009-03-10 at 09:58 +1300, Martin Langhoff wrote:
> On Mon, Mar 9, 2009 at 12:11 AM, Bryan Berry  
>  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/ vpn.png>___
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[Server-devel] notes on scaling ejabberd for the XO's

[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
 RESOLVED, ALREADYFIXED (but not in any deployments, or in the
UI)
 and the resulting chatter slows down the XO/Sugar
considerably?
 yes
 Robot101 rwh
 the latest versions of sugar and telepathy support using an XMPP
component called gadget
 instead of the shared roster
 Robot101: so gadget fixes this?
 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
 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
 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.
 Robot101: what is the testing status of gadget?
 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)
 Robot101: ok, will talk w/ them later today
 gadget was always our plan, it just took us a while to get to
it
 Robot101: by the way last year we tested ejabberd by streaming
your video talk on Telepathy to 80 XO's
 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
 bemasc: so it's still shared as in server-enforced mutual
visibility, just in smaller groups.
 right, but from ejabberd's perspective, it's individual rosters
 that's exactly how shared rosters always work
 the client thread gets a copy of the same roster at sign in
 oh? I thought there was a patch to ejabberd required.
 yes, he's patched it to source the shared roster from moodle,
I'd imagine
 martin seemed to say that he could use a totally stock ejabberd
 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?

[Sameer Verma]

On Tue, Mar 10, 2009 at 3:12 AM, Bryan Berry  wrote:
> On Mon, 2009-03-09 at 21:51 -0700, Sameer Verma wrote:
>> On Mon, Mar 9, 2009 at 7:04 PM, Bryan Berry  wrote:
>> > On Tue, 2009-03-10 at 09:58 +1300, Martin Langhoff wrote:
>> >> On Mon, Mar 9, 2009 at 12:11 AM, Bryan Berry  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/
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Re: [Server-devel] Serving 400+ students w/ a single central XS - ejabberd nightmare?

[Sameer Verma]

On Tue, Mar 10, 2009 at 6:14 AM, Daniel Drake  wrote:
> 2009/3/10 Reuben K. Caron :
>> 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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Re: [Server-devel] Serving 400+ students w/ a single central XS - ejabberd nightmare?

[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  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  :
>
>
>
> 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?

[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   :
  

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?

[Daniel Drake]

2009/3/10 Reuben K. Caron :
> 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!

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

[Reuben K. Caron]

Daniel Drake wrote:

2009/3/9 Bryan Berry :
  

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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