Stefan de Konink wrote: > Brett Henderson wrote: >> Anyway, happy to discuss. And I'd like to hear if there are better >> alternatives or if people think this is a bad idea. > > What about setting up a RSS with torrent files that seed the history? Perhaps it could form part of the solution. It is a good way of distributing large files that aren't updated at fast intervals (ie. the planet), so would be suited to distributing a single large history file or a large directory of history files.
I'm not sure if Bittorrent is a good way for distributing new daily files on a daily basis though. If I'm downloading changes I use the osmosis --read-change-interval task which reads the timestamp file on the planet server, reads the local timestamp file, then downloads all intermediate changes and merges them into a single change stream which then be applied to a local file or database. It can be launched from cron on a regular basis (every minute if necessary) to keep a local replicate up to date. It requires very little effort on the client side and is robust in making sure changes get applied in the correct order even in the face of networking problems. That would be very difficult to achieve with bittorrent and would add a lot of latency. So bittorrent could definitely be used as a way of people seeding their original database with historical data up to a point in time, but if they subsequently want to keep in sync with changes they may be better served by switching to direct changeset downloads. My suggestion would be to provide weekly merged changesets via bittorrent and make daily/hourly/minute? files available via direct download. What do you think? Brett _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
