[Tilesathome] Proposal: New T at H Server structure

[Johan Thelmén]

söndagen den 1 juni 2008 skrev Frederik Ramm:
> Hi,
> 
> > i have done quite some thinking lately how to speed up the tiles at home
> > upload. I've come up with an complete new structure of the server System.
> 
> There was a rather cool concept on the Wiki about a year ago where 
> we would distribute tiles using DNS, i.e. you would always find 
> the "responsible" server through DNS instead of through expensive 
> database lookups and HTTP redirects.

I have not given up on it. I'm just slow to implement it when I have no time for it.

> My personal thinking though is that we don't need a complex system 
> like that because as soon as chrschmidt gets the new disks, everything
> is going to run smoothly again.

There lots of things to improve that that a distributed system will solve.
But untill then, new disks will make it a bit better.

> A highly distributed concept, in my eyes, has one big drawback: We
> must assume that at any one time, a small percentage of tile servers
> will be down or slow. The usability of a map display is greatly
> reduced even if only one tile is missing. I would go so far as to say
> that a map consisting of 20 tiles, where one tile is a broken image,
> is a "failure". This means that if you get the tiles for one map
> display from 20 tile servers, then you have not a single point of
> failure, but 20 cascading single points of failure ;-)

I would have to prove you wrong at another time. With one server responsible to add and remove
and test the distributed servers will be able to detect when a server is failing, is slow
or lagging updates and will automaticly make a change in the DNS-zone to reflect this.

-- 
Johan Thelmén (jth & TeLLuS)
Falun Sweden