On Fri, Nov 6, 2009 at 2:06 PM, River Tarnell
<river(a)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.