Bug report #6941

WMS requests exceeding extents

Added by Jonathan Moules over 11 years ago. Updated over 5 years ago.

Category:Web Services clients/WMS
Affected QGIS version:1.8.0 Regression?:No
Operating System: Easy fix?:No
Pull Request or Patch supplied:No Resolution:not reproducable
Crashes QGIS or corrupts data:No Copied to github as #:16054


After some deliberation and investigation, I think this is a QGIS bug rather than GeoServer.
I have a WMS 1.3.0 layer being served by a GeoServer 2.2.2 install.

I start with a blank project and add a layer (this is so QGIS doesn't automatically pan to the WMS). I then make sure I am looking away from whereever the WMS layer will be added.
I then add the WMS layer.
At this point, QGIS locks up for about 30 seconds using 100% of the CPU.

Looking at the Geoserver logs, it seems that QGIS has made a request to the WMS and GeoServer is trying to serve it. The delay is GeoServer rendering a map with ~50,000 elements.
The bug is: the WMS can't possibly on the screen when I add it, the bounding boxes don't merge.
I'm viewing:
bottom left: 409355,378801
top right: 420152,384476

The bounding box of the layer as declared in GeoServer (and the GetCapabilities) is:

<BoundingBox CRS="EPSG:27700" minx="265000.0" miny="270000.0" maxx="285000.0" maxy="385000.0"/>

The request QGIS has made to geoserver is:

2013-01-03 17:37:08,553 DEBUG [org.geotools.jdbc] - Setting parameter 1 as MDSYS.SDO_GEOMETRY(2003,27700,NULL,MDSYS.SDO_ELEM_INFO_ARRAY(1,1003,3),MDSYS.SDO_ORDINATE_ARRAY(260137.473441875,262244.437679375,289324.518804125,392778.766678625))

Because the layer extent is declared in the GetCapabilities, QGIS should know not to request a map, let alone one of the entire area. ArcGIS doesn't make a request in these circumstances.

This even happens if I do it the other way - super zoomed in.
I'm viewing:
Bottom left: 278510,378502
Top Right: 278676,378568
Which is an area about 1.5hectares - zoomed to 1:380. This does include a small portion of the WMS area < 1%.

But QGIS is doing the exact same thing (or is inducing GeoServer to), requesting:


As you can see, its identical to the first bounding box requested when off the map. When I run this through Oracle its actually selecting every single feature!

This may be GeoServer, but as it doesn't happen with ArcGIS I'm inclined to suspect its QGIS.
I've attached the entire relevant part of the GeoServer logs. All of that happens between clicking "add" and the layer being added for the second example above.

geoserver_logs.txt Magnifier (4.57 KB) Jonathan Moules, 2013-01-03 10:27 AM


#1 Updated by Jürgen Fischer over 11 years ago

  • Subject changed from Bug - Adding WMS to WMS requests exceeding extents

#2 Updated by Giovanni Manghi almost 11 years ago

  • Priority changed from High to Normal

#3 Updated by Giovanni Manghi almost 7 years ago

  • Easy fix? set to No
  • Regression? set to No

#4 Updated by Giovanni Manghi about 6 years ago

  • Status changed from Open to Feedback

Please test with a recent QGIS release (2.18 or 3), if the issue/request is still valid change the affected version accordingly, if is fixed/implemented then close the ticket. Thanks!

#5 Updated by Giovanni Manghi over 5 years ago

  • Resolution set to not reproducable
  • Status changed from Feedback to Closed
  • Description updated (diff)

Closing for lack of feedback.

Also available in: Atom PDF