Hi,
I’m a bit confused and have a couple of questions to ask about GWC. My setup is geoserver 2.7.0 and I’m using the GWC bundled with that but using gwc endpoint rather than having the wms service auto-integrated. I’m doing this as I do not want any request been made direct to the WMS, everything must go through the cache so only my gwc endpoint is exposed on the proxy server.
The layers (actually layer groups should that make a difference) are setup in GWC using 3 gridsets:
900913 256x256 png (the built in one)
3875 512x512 png
27700 256x256 png
The first oddity I have found in the past is that after running for a while gwc seems to forget the fact that 900913 == 3875 for non-built in gridsets, hence the 512x512 cache we use for hi-res displays uses an ESPG of 3875, I used to use 900913 but after a few days of running it would start moaning about the client using 3875/512x512 as the srs saying it is not suitable. Worked fine ever since I switched it over to 3875. I can live with this so not really an issue for me to worry about.
My next oddity is the one that has me worried and seems concerned with default values for filters.
To support hi-res and normal res images on the first two gridsets above I have filter using FORMAT_OPTIONS as defined below
FORMAT_OPTIONS
dpi:90
dpi:90
dpi:180
Our main clients explicitly set the format options as required, however another client does not, I had expected that by providing a default that would be taken care off. We do get images from GWC which I guess is the important thing, however GWC appears to maintaining a separate image cache for requests that do not contain a FORMAT_OPTIONS parameter. Is this what people would expect, I assumed that a default value would contribute to which set of cached images were used.
My seeding process is done using dpi:90 and dpi:180, this suggests I should also be doing one without any options. This would seem a shame as my disk cache now uses half as much space with one third a duplicate.
Am I missing something obvious in the config or is this expected behaviour?
Kind Regards, Vic
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Victor Kirk
Senior Software Engineer
Cubic Transportation Systems (ITMS) Ltd
+44 1642 636894
Joint Winner, Operational and Technical Excellence, Contactless Bankcard Payment UITP (International Association of Public Transport) Awards 2015 Joint Winner, Best New Innovative Practice-Partnership Deployment, Ventra ITS-America Awards 2015 http://www.cubic.com/Transportation/About-CTS/Awards |
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