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

Jon Burgess jburgess777 at googlemail.com
Mon May 21 19:34:13 BST 2007


On Mon, 2007-05-21 at 01:06 +0100, Robert (Jamie) Munro wrote:
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> Jon Burgess wrote:
> > 
> > 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).
> 

Yes, I think something like this should be possible.

> 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 :-)
> 

That already exists. All tiles older than 28 days get dropped.


> 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 week out of date).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)...
> 

An alternative may be to take the a similar approach to the t at h layer,
by grabbing the live OSM data for the tile and re-rendering from that.

This could be done in a new layer to ensure that any problems with this
do not break the existing setup.

	Jon






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