[OSM-talk] tagging and rendering highways in the USA and elsewhere

[Martijn van Oosterhout]

On Sat, Apr 19, 2008 at 2:43 PM, Robert (Jamie) Munro <rjmunro at arjam.net> wrote:
>  Hopefully we won't need a separate tileserver for each rendering style -
>  1 server should be able to render more than one style at a time at
>  different URLs. I am led to believe that mod_tile cannot currently
>  render more than one style of tiles on a single apache installation - I
>  don't know what tilecache is capable of. It would be more efficient to
>  spread the load across multiple servers by odd/even tile numbers, or
>  possibly by odd/even zoom levels.

Tilecache can render as many layers as you want. I'm sure mod_til
could do the same with the appropriate hacking. The program is
diskspace. We're already calculating hundreds of GB for the current
map, doing that per country is going to be crazy, unless we are
donated a petabyte storage array.

Odd/even tiles is a waste, given metatiling renders an area larger
than the one you're viewing anyway. Doing it per zoom level might
work...

>  It is likely that a USA tileserver will be busy at different times from
>  a UK or Japan tile server, and it would be useful if they could share
>  the rendering loads between each at their own peak times.

AIUI we're limited by I/O not CPU, so we need to look at advanced
storage solutions. (And the appropriate performance improvements in
mapnik).

Have a nice day,
-- 
Martijn van Oosterhout <kleptog at gmail.com> http://svana.org/kleptog/