On Thu, Jan 22, 2009 at 10:26 AM, Steve Hill <st...@nexusuk.org> wrote: > On Wed, 21 Jan 2009, Chris Andrew wrote: > >> I notice that people often mention the delay in map edits being >> applied and made _live_. > > On a related note... > > For OpenPisteMap, I apply the diffs to the PostGIS DB every minute, so it > only lags behind the live data by a few minutes. However, it doesn't > currently automatically expire any tiles from the cache, so it won't > re-render a tile after the data has been changed.
this might be helpful http://svn.openstreetmap.org/applications/utils/export/tile_expiry/ > I'm currently working on modifying osm2pgsql to create a list of tiles > that have been changed as it applies the diffs so that they can be removed > from the cache (and thus re-rendered on the fly when someone requests > them). the above script expires meta-tiles with minutely updates. see the blog post here http://blog.cloudmade.com/2009/01/23/nearly-live-tiles/ and the tile server itself http://matt.sandbox.cloudmade.com/ >> With the OSM community growing by the day, this problem can only get >> bigger. Does anyone know whether anyone has consider using a >> distributed client [1] such as BOINC [2] to do the _number crunching_? > > From my experience, the number crunching doesn't really seem to be the > limiting factor - database I/O is the biggest overhead for OpenPisteMap > (although that may be partly down to the massive amount of SRTM contours > data it has to handle while rendering each tile). +1 this is one case where one big raid array is much better than many distributed disks. cheers, matt _______________________________________________ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb