[OSM-talk] Mapnik rendering update

[Jon Burgess]

On Fri, 2008-01-25 at 17:49 +0000, Thomas Wood wrote:
> I believe the mapnik tile server has been a little overloaded recently
> - queuing of new tiles was disabled for a time.
> 
> Rerender on ifw is for osmarender only (and isn't really required
> much, now that changed-tiles is being run to pick up data changes)
> 
> On Jan 25, 2008 5:36 PM, Gervase Markham <gerv-gmane at gerv.net> wrote:
> > Anyone know why Mapnik still hasn't rendered the data I put here:
> > http://www.openstreetmap.org/?lat=54.6134&lon=-2.6175&zoom=12&layers=B0FT
> > over a week ago? Osmarender has it fine.
> >
> > I've tried using the "rerender" command on informationfreeway. (Is that
> > Osmarender only?) I've tried "waiting until next Wednesday" and then
> > waiting a bit longer. I've tried going to the individual tile URL and
> > appending "/dirty"; "/status" then saying it's awaiting rerender, and
> > later it says it no longer is (so presumably it's been done) but yet, no
> > change :-(
> >
> > Sorry if I'm being thick. What am I missing?
> >

There is a major update to the way tiles are rendered occurring at the
moment, let me explain...

As Thomas mentions the rendering on the tile server has been overloaded
recently. I've been working on developing an improved version of the
software rendering framework called mod_tile for a few months and I took
the plunge this week to install and run it on tile. 

The old system used a Mysql database to store the tiles, the new one
uses the filesystem. I am currently running the list of 30M tiles from
the MySQL database through the new mod_tile rendering engine to build up
the new tiles from scratch. Right now all the tiles you are seeing are
coming from the MySQL DB. 

The tiles are still being rendered with the Mapnik renderer so the new
map will look the same as the old one. Many major changes have been made
to the other parts of the rendering setup to massively improve the
overall rendering speed.

Once this first pass of the rendering is complete the mod_tile setup
will have all the existing tiles fully rendered with the current planet
dump and current map style. At that point I will switch over the URLs on
the server to make the new tiles live.

The new system has already rendered 5M tiles in just under 24 hours.
This covers all of zooms 0 - 12 and about halfway through zoom 13. At
the current rate all the old 30M tiles will be rendered by about
Wednesday next week. 

Given how well things are progressing with the rendering I don't want to
attempt any hybrid schemes to mix the new and old tiles or transfer the
old tiles from the database to the filesystem.

The new rendering rate is about 5 times faster than the old setup and
allow us to be able to keep the tiles more up to date in future. The
weekly import of the planet dump data will still be a limitation for the
foreseeable future, but you should see updates appearing on the map much
sooner after the Wednesday each week.

Hopefully you can all live with a few more days delay in the updates
before you get a nice new set of tiles with faster updates in future.

	Jon