[OSM-talk] instant rendering of new tiles in mapnik layer

[Robert (Jamie) Munro]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Jon Burgess wrote:
> I've just made some changes to the Mapnik layer tile server to generate
> missing tiles on-the-fly. In most cases you should not see the 404 'more
> tiles coming soon' tile being returned. 

Fantastic! This seems to work really well for me. The tiles that are
being rendered are obviously slower than the ones that are already
rendered, but still perfectly usable.

> This extra load may adversely effect the performance of tile so I have
> placed some bounds on the maximum number of outstanding tiles. If this
> limit is hit you will get the old 'more coming soon' tile again. This
> might happen right now if you all rush at once to examine those zoom 18
> tiles!
> 
> The data used to render the tiles is still from the latest planet.osm
> dump so please do not expect any data that you have uploaded since
> Wednesday to appear until after the next planet dump.
> 
> Re-rendering of existing tile is still done as a background process so
> you may see stale data immediately after a new planet dump. I may extend
> the live rendering to include these tiles too if the current setup works
> well.

Ideally you should serve an old tile if the server is busy, but render a
new one if  the outstanding tiles number is low (a lot less than what
you use for the 'more coming soon' tile, so that new tiles take priority
over re-renders).

You might want to do something like flush out all tiles that haven't
been rendered for a month or something so that things don't get really
old with the above system, and to stop the disc filling with level 18
tiles of obscure places that one person visited once by mistake and no
one will ever look at again :-)

Having the whole world visible is a fantastic breakthrough (albeit a
week out of date). Thanks very much Jon.

Now all we need is a more frequent planet dump (or a more direct way to
get data into PostGIS)...

Robert (Jamie) Munro

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.6 (Darwin)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFGUOKbz+aYVHdncI0RAnTfAKDO4yefMx06N2r7FFTqBLQlgD00lQCdFT5l
OmqajDX/GQ4dUtq0uYZb+gg=
=+aNP
-----END PGP SIGNATURE-----