GeoServer caching request not aligned to grid(s) using different EPSG

Question

First up I've found several other posts on the same topic but neither seem to resolve my problem.

I am trying to create a geowebcache using the embedded geowebcache in Geoserver version 2.11.2

I have been working with two layers both have same problem. I've set the layers up in Geoserver using the extents computed from the SRS bounds. I have set up gridsets and seeded the tilecache. I can see this has been successful from the Tilecache preview in Geoserver.

If I then call the WMS from QGIS then the tile cache is not used (and is very slow as a result).

If I use curl to test the request using a URL I pulled from the layer preview in Geoserver I get the following result of misaglined grids:

geowebcache-cache-result:MISS geowebcache-miss-reason: request not aligned to grid(s) 'EPSG:27700'

The first layer I've worked with uses EPSG:27700

Gridset config is as follows:

The curl request uses:

C:>"C:\Program Files\cURL\bin\curl" "http://host/geoserver/ws/wms?service=WMS&version=1.1.0&request=GetMap&layers=ws:Aerial%20Imagery%202016&styles=&bbox=383000.0,380999.999998459,400999.999998448,395999.999999761&width=768&height=640&srs=EPSG:27700&TILED=true&FORMAT=image%2Fjpeg" -w content_type -v >nul

The second layer is actually one of the sample layers and sample gridsets that come as part of the Geoserver. I've used this as test to exclude any variables I may have introduced. However I get the same result.

Layer users EPSG:4326

The Gridset is:

The curl request is: C:>"C:\Program Files\cURL\bin\curl" "http://host/geoserver/nurc/wms?service=WMS&version=1.1.0&request=GetMap&layers=nurc:Img_Sample&styles=&bbox=-130.85168,20.7052,-62.0054,54.1141&width=768&height=372&srs=EPSG:4326&TILED=true&FORMAT=image%2Fjpeg" -w content_type -v>nul

Answer 1

It's easier to look at the second request, and it's clearly misaligned. In the 4326 gridset the longitude tile borders per zoom level are:

• zoom level 0: -180, 0, 180 (180 degrees tile)
• zoom level 1: -180, -90, 0, 90, 180 (90 degrees tiles)
• zoom level 2: -180, -135, -45, 0, 45, 90, 135, 180 (45 degrees tiles)

Now you have there a request going from "-130.851" to "-62.0054"... it's a 68-ish degree tile that does not fit anywhere.

If you are using WMS from QGIS the likeliness of hitting a cached tile is basically zero, you should be using a tile oriented protocol like WMTS instead.