[Openstreetmap] tile cacheing

[Simon Hewison]

SteveC wrote:
> I was thinking of the opposite. We use squid for caching and there are
> some fairly powerful tools for removing things from the cache, so a cron
> job could wake up every ten minutes and look for whats changed in the
> database and kill the tiles in the cache that contain those changes.

That would work too. However, you wouldn't want to set the HTTP expiry 
time too far in advance, else client side caching (which you have no 
control over cache invalidation) would take over, and clients wouldn't 
see updated tiles without flushing their cache.

> First I want to replace mapserver and speed up tile generation and only
> render streets if the zoom level is sufficient...

"Sufficient".. I think we really need the tag/value stuff to determine 
how "important" a given street is at a given zoom level.

eg. Display motorways when zoomed out to approximately country level, 
then dual carriageways, then main roads, residential streets, country 
lanes, paths etc.

-- 
Simon Hewison