Opened 10 years ago

Closed 10 years ago

Last modified 10 years ago

#1520 closed enhancement (invalid)

Automatically invalidate Map tiles on Upload

Reported by: lonelypixel Owned by: cbro@…
Priority: major Milestone:
Component: merkaartor Version:
Keywords: Cc:

Description

When you make changes to the map data, you need to request the Slippy Map tiles of that region so that they'll be updated on the following Wednesday. And it seems that at least I am missing this very often and so the map won't reflect my changes or is even broken at the tile borders. Requesting the Map in every zoom level for the entire affected region is an unproductive task since you won't see your changes anyway yet.

My proposal is to have Merkaartor automatically invalidate the affected map tiles by downloading them once, for all zoom levels. Or maybe for all zoom levels from 5 on or so. IIRC, there are also some status URLs to find out whether a certain tile needs updating. This could be done when uploading the map data so that the map will always be rendered with fresh data next time. If uploading data for an area more than once within a session (not restarting Merkaartor), the tiles wouldn't need to be invalidated again. (Remember a list of downloaded tiles.)

Change History (4)

comment:1 Changed 10 years ago by Tom Hughes

Resolution: invalid
Status: newclosed

It is not true that you have to request tiles to get the rerendered. All tiles are rerendered every week.

Please do not add this feature to merkaartoor - it will just add needless load to the tile server and force it to spend time sending tiles that nobody will look at rather than rendering them.

comment:2 Changed 10 years ago by lonelypixel

Then why do I often see outdated tiles on the openstreetmap.org map?

See also the OSM Wiki for the tech details, which seem to apply, according to my observation.

http://wiki.openstreetmap.org/wiki/Slippy_Map#Mapnik_tile_rendering

Maybe the rendering process should be changed to avoid this situation?

comment:3 Changed 10 years ago by lonelypixel

PS: Here's an example. One zoom level deeper and the track in the middle is missing. I've added it last weekend and not browsed the map since then.

http://openstreetmap.org/?lat=49.57003&lon=11.17476&zoom=16&layers=B000FTF

comment:4 Changed 10 years ago by Tom Hughes

You would need to check with Jon Burgess, but I don't believe that description on the wiki is accurate.

As to your example, we're only about 24 hours into this weeks render so it may well not have rendered yet - rendering everything takes most of the week. Visiting the tile may have the effect of speeding that up because the server tries to rerender tiles on demand as people view them if it can. If it is too busy it will serve the old one though and the background rerender will eventually catch up with it.

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