GeoWebCache is really a separate server that is embedded within GeoServer and it offers a different set of services from those offered directly by GeoServer from a separate endpoint.
GeoServer doesn't really know anything about how GWC handles a request. It just delegates certain requests to GeoWebCache, which then checks its cache and responds with that, or requests the image from GeoServer's WMS service. /geoserver/wms is the regular GeoServer WMS endpoint /geoserver/gwc/service/wms is the GeoWebCache WMS-C endpoint that serves tiles from the cache. There is a "Direct Integration Mode" setting which will cause requests to GeoServer's regular WMS endpoint that have "tiled=true" set to check if GWC can handle them, and if not they are handled normally. I don't recommend relying on this as it is far to easy to end up bypassing the cache without realizing it. I don't recommend turning this on as it just leads to silent changes in behaviour. GWC stores the exact rendered tiles it will respond with. If you tell it to cache PNG, it will store PNG images in the cache, and when you request a tile, it will just stream the tile straight from storage into the network connection. If you tell it to cache JPEG as well, it will store those as a separate set of files. If you tell it to use a different gridset to arrange the tiles, that's stored separately. If you want to cache multiple styles, those are cached separately. Tile protocols like WMTS, WMS-C, or TMS include information in their capabilities documents to tell clients how to make requests that align to the grid or you can just configure the client to align to the grid if it doesn't support configuration from a capabilities document. If they receive requests that don't match, they will generally respond with an error. There is an option called "full WMS" available for WMS-C which will cause it to fuse, crop, and rescale tiles from the cache to handle arbitrary WMS requests, but this is slower and doesn't look as good so it's usually not worth turning on. On 2019-05-22 1:06 p.m., Barry Carter wrote: > Hey you guys, > > I used a large gray image as a store, and then used tile caching to > make it display faster. Do the tile caches apply only to the gray > image? I'm guessing yes since the cached tiles are stored as > PNG/GIF/JPG and not GeoTiffs themselves, but wasn't sure. For example, > it's theoretically possible that GeoServer reads the gray tile and > changes the colormap before sending it to the client. > > Are cached tiles only used if the client requests tiled mode? I'm > again guessing yes, but it's possible that tile caches make it easier > to assemble images at lower zoom levels. However, it's possible > GeoServer uses the data directly when tiled mode is not requested. > > Suppose I create a tile cache using the PNG8 format. Can GeoServer > tell or force the client to only requests maps in this format? I > assume that, if the client requests JPG format, the tiles are of no > use to me (unless GeoServer does PNG8 to JPG conversion on the fly), > so I'd like the client to use the most efficient method. > > > > _______________________________________________ > Geoserver-users mailing list > > Please make sure you read the following two resources before posting > to this list: > - Earning your support instead of buying it, but Ian Turton: > http://www.ianturton.com/talks/foss4g.html#/ > - The GeoServer user list posting guidelines: > http://geoserver.org/comm/userlist-guidelines.html > > If you want to request a feature or an improvement, also see this: > https://github.com/geoserver/geoserver/wiki/Successfully-requesting-and-integrating-new-features-and-improvements-in-GeoServer > > > > [email protected] > https://lists.sourceforge.net/lists/listinfo/geoserver-users -- Kevin Michael Smith <[email protected]>
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_______________________________________________ Geoserver-users mailing list Please make sure you read the following two resources before posting to this list: - Earning your support instead of buying it, but Ian Turton: http://www.ianturton.com/talks/foss4g.html#/ - The GeoServer user list posting guidelines: http://geoserver.org/comm/userlist-guidelines.html If you want to request a feature or an improvement, also see this: https://github.com/geoserver/geoserver/wiki/Successfully-requesting-and-integrating-new-features-and-improvements-in-GeoServer [email protected] https://lists.sourceforge.net/lists/listinfo/geoserver-users
