[prev in list] [next in list] [prev in thread] [next in thread] 

List:       timekeepers-dev
Subject:    [time-dev] Updates on the new DNS
From:       gfk () logidac ! com (Guillaume Filion)
Date:       2007-06-30 17:19:58
Message-ID: 468690BE.8070202 () logidac ! com
[Download RAW message or body]

Simon Lyall a ?crit :
> All we need to know is roughly which servers are probably closer and to
> spread the load out a lot. Even for a large country like the US we could
> chop it into 100 random sections, put a couple of servers in each and just
> distribute all US based queries evenly between them without anybody
> noticing.

I'm already doing this in the way I store the servers in the CDB file.
The world is divided in 64800 sections (360 degs of longitude x 180 degs
of latitude). When a client sends a query, I lookup
$hash->{round(client->lat)}->{round(client->lon)} and it gives me the
list of servers in that section. If that section is empty, I do a
"spiral-search" around it until I find enough servers.

> Do we really need *very* good location information? Most of the users
> for this information will use it for targetting advertising, etc and
> need very good data.
> [...]
> Right now people easily get a server on the other side of the world so a
> "vague effort" to give a close on is probably good enough

The thing that bums me with GeoCity Lite is that it returns a default
value for each country when it doesn't have precise data for an IP. The
problem is that with big countries like the USA or Canada that default
value is in the middle of the country, which is likely to be thousands
of Km away from the real position.

A while ago, I hacked a GeoIP-blacklist that would recognize these
bogus/default returns and try another service. But that's the kind of
half-backed solution that I'd like to avoid by finding a "real" GeoIP
service. :-)

I'll see if I can convince MaxMind et al. to sponsor our project. If
that doesn't work, Ryan Malayter has proposed an interesting solution in
the wiki (http://www.socialtext.net/ntp/index.cgi?dns). That would be to
 return a random server for that country when we get the default
position. That would be as precise as the actual system, but at least
users wouldn't need to specify their zone.

Cheers,
GFK's
-- 
Guillaume Filion
http://guillaume.filion.org/

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 250 bytes
Desc: OpenPGP digital signature
Url : http://fortytwo.ch/mailman/pipermail/timekeepers-dev/attachments/20070630/70ac09f0/attachment.pgp 

[prev in list] [next in list] [prev in thread] [next in thread]