On Fri, Nov 6, 2009 at 2:06 PM, River Tarnell river@loreley.flyingparchment.org.uk wrote:
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Peter Körner:
If we could set up mapnik on the login servers
is any set up required besides installing it?
Mapnik needs to be on the normal user servers (e.g. webserver) if users want to for example create custom OSM wallpaper images or something other than tiles.
Mapnik in its normal operation will connect to a PostgreSQL server defined in your stylesheet. If the user supplies cassini as the remote server and has appropriate permissions this should just work.
However if we're going to do on-demand rendering on the tileserver this user-supplied stylesheet will have to be moved over there. Alternatively if someone would implement something that did what renderd does in e.g. FastCGI this could be on a normal webserver. What renderd does is basically:
1. Get a GET request like /foo/18/136758/91112.png 2. Render the stylesheet cofigured for /foo/ at zoom level 18, tile 136758x91112 by calling out to mapnik 3. Put the rendered tile in a tile store 4. Serve it to the user 5. When the tile is requested next time skip step 1-3 (unless it's expired)
Tile expiry is relatively simple. Basically you can either just run a find(1) command in cron and remove everything older than N seconds. Or you can have osmosis compute a list of changed tiles every time it applies a diff and that can be piped into rm -rf.
(bah)
Anyway regarding installing it we need to have a pretty recent version of mapnik since the osmosis/osm2psql/mapnik chain is pretty bleeding edge. Currently OSM rendering only works with mapnik >6.0 (and maybe only 6.1?).
Put some HD-Space from ptolemy or from a store ;) into cassini
the current plan seems to be swapping cassini and ptolemy, so ptolemy (which has twice as much space) will become the OSM Toolserver.
Connect Postgresql with LDAP and open it read-only to the regular login- & webservers.
i don't think using LDAP is a good idea. it will encourage users to write their LDAP passwords into their tools, and it's not uncommon for people to expose these passwords due to programming errors. while LDAP passwords can't be used to log in, it seems better to use separate database passwords, like we do for MySQL.
Sounds nice. Should also be simpler so set up.
i can't comment on the OSM-specific tasks as i don't know much about that.
What are yours?
Marcin and i have agreed on a plan for ptolemy: it will become the OSM Toolserver, running PostgreSQL and Apache (for tiles), but with no user access. OSM tools will move to the regular Toolserver, and access ptolemy remotely. we are currently waiting on WMF approval to implement this.
Yay.