On Nov 1, 2010, at 4:14 AM, John Mitchell wrote: > Dane, > > Regarding your response: > > ------------------------------------------------------------------------------------------------- > > Good question. You mean WMS vs Tiles rendered on the fly and not cached? I > don't know, and its hard to say how you could test that correctly, because > most tiled implementations are rendering metatiles. But, I'll certainly keep > it in mind for the future. > > -------------------------------------------------------------------------------------------------- > > Actually I mean the performance of WMS tiled rendering vs. how > openstreetmap.org does tiled rendering (mod_tile) or does it all come back to > mapnik which all of these use to do the rendering.
Ah, I see. > The reason why I ask is that I have heard in the past that WMS rendering is > more expensive than mod_tile/openstreetmap.org protocol rendering. Yes. mod_tile avoids the http overhead, has the ability to render in multiple threads, and can render metatiles (which is more efficient overall). > > I currently have geowebcache on top of apache/ogcserver/mapnik which outputs > as tiled WMS and only has to render for non-cached areas and I am thinking > about in the future possibly switching to using mod_tile/mapnik which outputs > as tiled non-WMS format and I believe also only have to render for non-cached > areas. Correct. > I am wondering if using mod_tile is more efficient than tiled WMS. Yes, I would strongly presume so. > The reason why I went with ogcserver as tiled WMS was that some of our > customers required it to be WMS but that may be changing in the future, so I > would have the option to output as tiled non-WMS in the future, but I want to > see if it's worth my time to switch over to mod_tile/mapnik. I think if you don't have to support arbitrary WMS requests, then just rendering and caching on-demand (meta)tiles will be more efficient. > > Another reason that I did not try mod_tile/mapnik is that effort for the > initial configuration of mod_tile seemed overwhelming, It certainly is not a trivial setup. And, only works on linux/mac osx - you were on windows last I remember? > but I noticed that you have set up scripts (link below) to install mapnik, > osm2pgsql yes. > and mod_tile no, not mod_tile sorry. I have been meaning to get complete docs updated for the foss4g workshop on mod_tile (also mod_tile + tirex), but I've been short on free time and even when I do they will only be for linux/mac osx. > within Ubuntu linux which appears to make it easier to install mod_tile than > the openstreetmap.org documentation. > Actually my hope is to update both the official readme and those foss4g step-by-step notes. > http://bitbucket.org/springmeyer/osm-rendering-workshop/src/c74fa9e14020/installing.rst > Btw, those are the sources, but the HTML is here: http://dbsgeo.com/foss4g2010/html/ > > John > > > > > > Thanks, > > John >
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