[ka-Map-users] Best Linux file system type for ka-map cache?

Attila Csipa plists at prometheus.org.yu
Tue Oct 23 14:19:27 EDT 2007

On Tuesday 23 October 2007 19:08:21 Stephen Woodbridge wrote:
> One of the easiest and fastest ways to do this is to just delete the
> files if you have a fully populated tile cache, and then create a 404
> handler that returns a standard blue/black/whatever tile if the
> requested tile is not found. This is easy to do with apache2.

I wasn't thinking about this as a handler for full caches or missing tiles, 
but rather as a separate non-file based cache for repeating tiles. Let's say 
you have areas on your map you do not have data for, these will usually turn 
up black, but then again, _at the same time_ you might also include large 
areas of water which will be blue. Depending on your config, you might end up 
with thousands of physically identical files, which only slow you down. The 
404 approach, while excellent as a quick hack, is tricky since you cannot 
have different colored tiles at the same time and does not apply to maps that 
generate their tiles on the fly. The original idea (if I got it right) is to 
have the same appearance of the map itself, with the same number of tiles 
from the aspect of the client, but without having redundant data/tiles on 
server side.

BTW An upgraded version of the 404 handler would be not to serve the image, 
but to do a redirection to a static image. This way, after loading the first 
tile, ALL black tiles will be loaded instantly (only the header need to be 
read from the http connection, the browser cache will handle the rest).

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