Data updated but tiles still show last week

• Response headers show Age: 2412 and X-Cache: Hit from geowebcache.
• Zoom 14 is half new and half old with a visible break at the tile boundary.
• Low zoom levels are fresh while high levels still show the previous roads.

1. Request the same tile with a random query parameter and diff the two images to bypass the cache.
2. Read Age and X-Cache to identify whether GWC, the CDN or the browser served the stale copy.
3. Check whether the seeding job for that zoom range actually ran and covered the whole extent.
4. Check whether only some zoom levels were re-seeded.
5. Check CDN and browser Cache-Control separately, since different regions may see different versions.

Truncate the layer through the GWC REST API with a seedRequest containing type truncate over zoomStart 0 and zoomStop 18, or add a data version to the tile path such as /tiles/roads/v20261029/{z}/{x}/{y}.png so a new URL is a new cache key. For frequently changing layers set expireCache and expireClients to 60 seconds or serve them as dynamic WMS.

HTTP/1.1 200 OK
Cache-Control: max-age=3600
Age: 2412
X-Cache: Hit from geowebcache

curl -s -o /tmp/t1.png "https://gis.example.cn/geoserver/gwc/service/wmts?SERVICE=WMTS&REQUEST=GetTile&LAYER=workspace:roads&STYLE=&TILEMATRIXSET=EPSG:900913&TILEMATRIX=EPSG:900913:14&TILEROW=2418&TILECOL=10521&FORMAT=image/png"
curl -s -o /tmp/t2.png "https://gis.example.cn/geoserver/gwc/service/wmts?...&_=1700000000"
md5sum /tmp/t1.png /tmp/t2.png

• Clearing only GeoWebCache while the CDN edge and the user's browser still hold the old tiles.
• Waiting for max-age to expire instead of truncating, so traffic keeps hitting stale tiles for the whole cache lifetime.