[OSM-talk] tiles at home 404 handler, and assumed seas

[OJW]

Various people have requested that unknown locations (places without any 
rendered map tiles, that haven't been specifically marked as land or sea) 
should be blue, on the assumption that:
* there is more sea than land
* the amount of unmapped land will reduce over time
* renderers are more likely to discover and mark blank-land areas than they 
are to inform the server about blank-sea areas.

(the latest rendering client, "Headingley", can tell the server about blank 
land or sea tiles, which get stored in a database instead of being saved as 
images.  This database could later be exported as a binary file, if people 
want to suggest efficient ways of doing so)

So now, areas without any data are being returned as "404 assumed sea" images.  
This has the side-effect that some inland locations without any map data will 
also be blue.

I believe (can some 'close-area' developers confirm this?) that these areas 
will automatically be marked as "blank land" next time they're re-rendered, 
making the maps white again inland.

So if there's a particularly jarring area of assumed-sea on your maps, try 
requesting a re-render [1].

Tiles at home requests queue has been restarted, and currently has a backlog of 
about 5000 tilesets (looks like about 2 days' worth if you extrapolate the 
curves on [2]).

Regards,

OJW

p.s. some caches have cached error messages from when the system above was 
still being developed, so choose "tiles at home (direct)" on informationfreeway 
to be sure you're looking at the dev server.

[1] http://informationfreeway.org/ or 
http://wiki.openstreetmap.org/index.php/Tiles%40home/APIs#Requesting_updates
[2] 
http://munin.openstreetmap.org/openstreetmap/dev.openstreetmap-tilesathome.html