Re: [alto] How Data Center Virtualization influence ALTO mechanism.

[Enrico Marocco <[e-mail]>]

On 10/12/10 9:17 AM, Lars Eggert wrote:
>> IP-based, Vms are closer to DC-A. Physically, these VMs are much
>> closer to hosts in DC-B. However things are not so easy, especially
>> considering how these VMs are routed. Current ALTO may give wrong
>> cost ranking.
> 
> If you're moving VMs around in the topology, you'll have to update
> the announced ALTO information as you do that.

According to a presentation I saw last year, this is actually what
happens in Facebook's server farms, where BitTorrent and a customized
locality-aware tracker are used to distribute software updates
minimizing inter-rack traffic. Whenever the topology changes -- and I
guess that happens quite often -- the updated information is directly
loaded into the tracker. I don't remember how the update mechanism works
in that specific case, but I guess that could be quite effectively
automated with some kind of integration between the ALTO-like service
and some IGP database.

I can't find a pointer to that presentation, but an article and a video
explaining how software update works in Facebook is available on
TorrentFreak:
http://torrentfreak.com/facebook-uses-bittorrent-and-they-love-it-100625/

-- 
Ciao,
Enrico