[QGIS-Developer] QGIS WMS provider firing too many requests !?

[Richard Duivenvoorde]

Hi,

As a vivid WMS user/debugger, I see that QGIS is firing 9 requests per 'view-extent' currently.

I'm aware of cache etc etc... but... especially when using temporal filters for example, do others agree with me that this is more or less useless?
I'm also aware that a lot of WMS are actually just WMS interfaces in front of a cached WMTS, but still.

- some (governmental) services nowadays are still free for fair use, but: firing 9 times the actual requests costs resources/energy/maybe money
- before the WMTS I ran WMS services sometimes with pretty heavy styling, so on higher zoomlevels you do NOT want your clients to fire 9 requests, and just effectively use 1 ...

So in short: should I try to add some kind of (hidden?) option to minimize the number of requests?

To test a wms of all municipalities of NL:

https://geodata.nationaalgeoregister.nl/bestuurlijkegrenzen/ows?SERVICE=WMS
(layer 'gemeenten', EPSG:28992)
And look in F12/debugging window the number of GetMap requests fired when zoomed in...

I copied/created polgyons of the requests, and (see screenie) indeed looking at the center 'tile', the 8 surrounding requests are also fired....

Currently looking into this.

Regards,

Richard Duivenvoorde


 
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