[Qgis-user] Speed up loading a project, by postponing fetching WFS features

[Stewart Holt]

I have for years noticed the same thing. I also have about 30 WMS and WMTS
layers which are mostly USGS National Map product layers and a few ESRI.
When QGIS starts, I see in the status bar, each layer that is loaded. It
rips through my shapefiles and then takes quite a bit of time to "load" the
WMS/WMTS layers. Only about 2 of these layers are checkmarked to be
displayed at any given time. QGIS apparently does some initialization on
these layers, even if they are not to be initially displayed. While it is
valuable to get a full check of the availability of layers on startup, it
would be much faster to either lazy initialize these as needed or to spread
it out over my 24 cores to do it in parallel. Occasionally some or all of
the layers are not available for periods of time. When this happens, it
really takes a long time to startup. I have set the network timeout from
the default (1 minute?) to 15 seconds to make that situation less painful.
I think the delay is caused by the time it takes for the WMS service to
respond, not processing time. My internet connection is 1 Gbps.

I think one of the best solutions would be to load the network based layers
marked to be displayed, then make the map canvas available for use and
either continue to load the remaining layers in the background or lazy
initialize them as needed. I wonder how many others face this situation and
if there would be sufficient interest to submit a request for an
enhancement.

Thanks,

Stewart Holt
Georgia Appalachian Trail Club GIS


On Fri, Jul 19, 2024 at 5:04 AM Thomas Larsen Wessel via QGIS-User <
qgis-user at lists.osgeo.org> wrote:

> I have a project with roughly 30 WFS layers. Most of the layers are
> disabled by default, and I rarely have more than 10 of those layers enabled
> in any session.
>
> But as far as I can tell, it loads all data from all WFS layers, no matter
> if the layers are enabled or not. Am I right?
>
> Does this happen in sequence or in parallel?
>
> It takes 100 seconds from clicking open, until the GUI updates to show the
> loaded project (for the above mentioned project with 30 WFS layers). I
> believe the Internet connection is the bottleneck. Often I'm on a cell
> phone connection, and the load time is much worse.
>
> Is there anything I can do to make it not load all WFS data right away? Eg
> not load features from any disabled layer, until I actually need it?
>
> Sincerely, Thomas
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