On Tue, Oct 20, 2009 at 04:25:01PM +0300, Adrian Popa wrote: > Thank you, > > I'll try with mod_python. > > Another small question - is there any notable speed difference between > using tilecache (let's say through mod_python) to serve some pre-cached > tiles and using OpenLayers.Layer.Tilecache to serve the same pre-cached > tiles?
Some. The key difference is that serving pre-cache tiles can be done on much lower resource webservers. mod_python can get bulky, but Layer.TC can read from a minimal webserver like lighthttpd, etc. that tileCache itself wouldn't want to be run on. > I'm thinking if I should pre-cache my whole map and use Layer.Tilecache > or if I can get away by using tilecache.py... You probably don't need to pre-cache your whole map. You will see a tremendous speedup switching to mod_python. > Has anyone done any benchmarks for these methods? If the speed > difference isn't that great, I wouldn't sacrifice the disk space... The speed difference is not quite nonexistent, but is negligable for anything but the most demanding use case (hundreds of users, etc.) > Thank you. > > Christopher Schmidt wrote: >> On Tue, Oct 20, 2009 at 09:43:35AM +0300, Adrian Popa wrote: >> >>> Hello Christopher, >>> >>> Thanks for your reply. >>> >>> I am using cgi mode (because it's been the easiest to setup). How do >>> you recommend I run tilecache? I don't want to precache my whole map >>> because most of the zoom levels (in some areas) don't give much >>> information. I could precache some zoom levels and let the details be >>> rendered on the fly, when needed... >>> >> >> Okay, using CGI is the problem. You can only get about 10 tiles/second >> with CGI, compared to hundreds with WSGI, mod_python, etc. So I recommend >> setting up mod_python or some other persistant server side process for >> serving the tiles, rathere than using CGI, which is much slower. >> >> >>> I'm not using metatiles (or at least I think I'm not using them)... I >>> don't really know what metatiles are and what they are supposed to >>> do. Maybe a point to the right documentation would be ok... >>> >> >> >> >> >>> The tile loading process goes like this - when I change my zoom the >>> center tiles are loaded pretty quickly (even if they haven't been >>> cached) - in about half a second, but the edges of my image take >>> about ~5 seconds to load. I thought it might be a limitation of my >>> browser - on how many connections it can keep - so I added a lot of >>> connections (20 per server) both on my browser and my web server >>> (20 processes listening). The speed limitation is visible even when >>> the tiles (for that area) have been cached. I thought that by >>> increasing the tile size the browser would make fewer requests and >>> the page would maybe load faster... >>> >>> Thanks, >>> Adrian >>> >>> >>> >>> Christopher Schmidt wrote: >>> >>>> On Mon, Oct 19, 2009 at 02:30:44PM +0300, Adrian Popa wrote: >>>> >>>>> Hello everyone, >>>>> >>>>> Just wondering - what would be a good tile size to be used for >>>>> tilecache, so that the client will not do a lot of queries to the >>>>> server (seems they take quite a while), and at the same time >>>>> would not load too much information that is not used (areas of >>>>> tiles which are outside the viewable area). >>>>> >>>>> My web clients use screen resolutions starting from 1200x1024 >>>>> (and usually run the page in full screen). >>>>> Right now I have tiles of 256x256 - which seem rather small and >>>>> take some time to load. >>>>> >>>> I would try to understand why they take some time to load. Are you using >>>> CGI mode? (Don't.) Are you not-precaching as much as you should? Are you >>>> using metatiles? Are you not using metatiles? etc. >>>> >>>> Also, some description of 'some time' -- hundreds of milliseconds, seconds, >>>> dozens of seconds -- would probably also be appropriate. >>>> >>>> >>>>> What tile sizes do you use? >>>>> >>>> 256x256. And so does Google Maps, which was doing this before most of us, >>>> and probably has a decent idea on how to make things work pretty well. >>>> >>>> -- Chris >>>> >>>> >>>>> Thanks, >>>>> >>>>> Adrian >>>>> >>>>> _______________________________________________ >>>>> Users mailing list >>>>> [email protected] >>>>> http://openlayers.org/mailman/listinfo/users >>>>> >>>> >>> >> >> > -- Christopher Schmidt MetaCarta _______________________________________________ Users mailing list [email protected] http://openlayers.org/mailman/listinfo/users
