[Openstreetmap] Re: [Openstreetmap-dev] Cache the whole world.

[Erik Johansson]

On 2/16/06, Lars Aronsson <lars at aronsson.se> wrote:
> The 48 hours is the worst kind of compromise.  It's too long when
> updates are made, and it's too short when no updates are made.
> What we need is a way to invalidate the cache on updates.  Then
> the expiration time can be set to two weeks, months or years.
> I don't see any trac ticket for this need.  I was almost certain
> it had been suggested already.  Should I add a ticket?  Wasn't it
> mentioned that Squid has some API for this?

Yes squid has an API and the track number is #121 as you discovered. ;-)

The biggest problem is that no one has written a "this lat/lon belongs
to these tiles" tool.


The other problem with invalidating is that there are lots of zoom
levels. Why not disabling the Landsat for zoom 16,17,18, or completly?
I'm not even sure you need landsat for zoom 15.

Do we really need zoom level 16,17,18? Zoom 16 is a about the same as
the best from other maping services in Sweden. E.g. moving half a
screen in 16[1], will move the viewpoint by 0.013 and 0.04 degrees.
That's ~250 meters in Sweden, do we really need a better zoom?



[1]
If you need to test this use where things are cached:
http://www.openstreetmap.org/index.html?lat=59.30732358896654&lon=18.040325953125&zoom=14
http://kartor.eniro.se/query?what=map&mop=mc&streetname=liljeholmen%2C+stockholm&streetnumber=&city=&zipcode=&mapstate=5%3B1627310%3B6578463%3B0%3B1624449%3B6580751%3B1630173%3B6576176%3B&mapcomp=%3B%3B%3BLiljeholmen%3B%3B%3B11761%3BStockholm%3B%3B%3B%3B%3B1625907.0%3B6579084.0%3B0%3B0%3B0.0000%3B0.0000%3Bmaps_place.42254.21&search_word=&where=&header_code=&heading=&heading_group=&selected_header_code=&company_name=&dir_area=&geo_area=&district_code=&ns=&stq=0&ax=&pis=&click_id=&symbols=&layers=&map.x=251&map.y=217

--
/Erik