What's the current status of the DB server?

I'm hacking the SlippyMap extension and it would be useful to work on one of the hard parts soon. I.e. how we want to generate a static map image from the database and having a working OSM -> OSM DB -> Mapnik DB -> Tileserver is required for that.

We'll have to figure out what's the best way to do this. One option would be to merely use this:

http://svn.openstreetmap.org/sites/tile.openstreetmap.org/cgi-bin/export

It's very resource intensive to render like that but perhaps we can stick a cache in front of it (with an expiry of e.g. 1 week) and get away with it.

Another option is to use something like this:

http://dev.openstreetmap.org/~ojw/StaticMap/

That's a script that generates a static map by assembling tiles. It has some neat features like adding a marker to the final image which we might want to adopt.

But we can use the cgi-bin/export script and just post-process its output to get the same results.

But generating a lot of tiles *first* and then generating static map images is something I'm not at all convinced is a good idea. You'd have to deal with all sorts of uncomfortable cases like the tiles you want to use not existing at the moment you're generating the map.

Besides, unlike OSM Wikimedia's primary application (at least for now) is going to be biased towards static maps as opposed to tiles. The opposite of what OSM itself is doing really.

Note that we can use the cgi-bin/export script and just post-process its output to get the same results.

Daniel suggested that perhaps we could just stick our generated maps in the thumbnail cache. This is a very interesting idea and something I'll have to look at further.

It's simple, and we automatically have a per-project namespace so we can do per-project renderings, i.e. German tiles for dewiki, English for enwiki, as determined by name:CODE tags in the OSM DB.

However we end up generating things we're going to have to cache them somehow, and do cache expiry. The latter being the hard part.

I'm not at all convinced that coming up with some elaborate caching system that can automatically expire our generated tiles once the OSM data they're generated from changes, that would require all sorts of complexity.

Instead it might be much easier just to assume that everything we generate can be put in the cache for a set amount of time, and after that period we'll have some method of automatically expiring everything.

What do you think?

Oh, and here's the new buglist: http://tinyurl.com/kuv9v8

Please add stuff that needs to be worked on.