[Geoserver-users] Geoserver web cache won't show tiles

[Kaspars F. <la...@la...>]

Hi!

There is an issue with GeoServer Web Cache I've been battling with for some
time now. A year or two. The solution which always works, is to remove and
create the buggy layer in the Geoserver, and GWC issue is automagically
fixed.

So, we are generating PNG layers from PostGIS. EPSG:900913, using via
Leaflet as a WMS layer. As a last resort, I've manually entered the
bounding box (2285772.8938 7460253.9606 3177334.3918 8006931.5869), which
corresponds to covered territory with a small extension. Native SRS is
EPSG:3059.

Mostly layer works OK, but once in a while, it misses a tile. For example,
a feature is shown on one zoom level fine. However, when I zoom in, tiles
don't show that feature anymore. It affects some features, as others are
visible on all zoom levels.

Following request generates tile successfully:

service=WMS&request=GetMap&layers=test-layer&styles=&format=image%2Fpng&transparent=true&version=1.1.1&width=256&height=256&srs=EPSG%3A900913&bbox=2739503.0937407175,7866287.45488406,2778638.852222727,7905423.213366073

This one returns a blank tile with a GWC log entry of "INFO
[util.ResponseUtils] - Read 425 from blank PNG file (expected 425)."

https://kartet1.lmt.lv/geoserver/gwc/service/wms?&service=WMS&request=GetMap&layers=test-layer&styles=&format=image%2Fpng&transparent=true&version=1.1.1&width=256&height=256&srs=EPSG%3A900913&bbox=2759070.972981722,7885855.33412507,2778638.852222727,7905423.213366073

However, most of the blank tiles are generated without any entries in GWC
log file.

Truncating layer does not fix the issue (I can confirm that the layer
physically gets truncated and files are removed). It can be fixed only by
removing layer (or layer group) from GeoServer altogether and re-adding it
back again.

This was not a big issue when layers were mostly static. Now, however, it's
a pain, since they have to be regenerated nightly. So, if there I'm unable
to get to the bottom of this bug, only way would be to automate layer
deletion and recreation via GeoServer's REST API, which is not something
I'm looking forward to...



-- 
Kaspars
http://laacz.lv/