In T269984 we see that a gracefully degraded map is produced when a geojson group cannot be found. These images should be considered a temporary failure, and served with headers to prevent standard 1-month caching. The image will heal once the group becomes available.
However, we should still guard against DDOS in case the geojson mapdata uplink breaks and many images can't be served with their overlays. Maybe degraded failures get a 1-hour cache expiry?
| Subject | Repo | Branch | Lines +/- | |
|---|---|---|---|---|
| [WIP] Match cache headers to response | mediawiki/extensions/Kartographer | master | +30 -1 |
Note this is very closely related to T295050#7489619, but kind of the opposite: Here we want less aggressive caching. This here is also on another layer, in Varnish.
We pulled this into our current WMDE-TechWish-Sprint-2022-02-02 to move this forward, investigate, and come up with concrete proposals. But it doesn't need to be 100% resolved in this sprint.
Change 779520 had a related patch set uploaded (by Awight; author: Awight):
[mediawiki/extensions/Kartographer@master] [WIP] Match cache headers to response
However, we should still guard against DDOS in case the geojson mapdata uplink breaks and many images can't be served with their overlays. Maybe degraded failures get a 1-hour cache expiry?
In T301341 we're discussing preventing any caching on error—these decisions should probably be aligned.