How can I update old tiles with 000-default file?


I run my own tile server with mod_tile. Every 4 month I would like to update the database and I would like that users, whe request tiles push the server to render new tiles.

Playing with generated tiles by setting the date with touch to different dates I found out that the tiles must be alter then around 7 month to be rendered again.

This is confusing because the settings in 000-default file persuade me that tiles would be rendered anyways with the default settings (I left the other settings untouched, because it seems to me that they are not relevant):

ModTileCacheDurationMax 604800 (7 days)
ModTileCacheDurationMinimum 10800 (3 hours + 3 hours for “fuzzy”= 6 hours)
ModTileCacheDurationMediumZoom 13 86400 (1 days)
ModTileCacheDurationLowZoom 9 518400 (6 days)
ModTileCacheLastModifiedFactor 0.20

In that case I assume that tiles below zoomlevel 9 be rendered if they are older than 16,8 days (or a maximum age of 15,9 days below zoomlevel 13).

It didn’t worked as expected. I set the tiles using “touch -t” to one month older, then to 2 month … after 7 month the tiles were renewed. That’s much more than I expected by the explanation of the 000-default file.

In the 000-default file is something written about heuristics. Maybe they have something to do with that?

I hope that someone could explan me how to set the values to render e.g. tiles again at all zoomlevels which are older then half a year.


You update a database with osm data? Not a database with your tiles? (Because the tiles are just on the harddisk in their directories?).

So why don’t you manually delete all tiles from your harddisk right after updating the database?

I’m puzzled which calculation would lead to values 16,8 and 15,9.

But you are not showing here exactly how you did that for 1,2,3 … months or what that file instructed.

Not that I have any experience with mod_tile…

I found the solution by myself:

The tiles are re-rendered if they are older than the the timestamp of planit-import-complete (in /var/lib/mod_tile).

Thats all.

It seems to me that the settings I was suspecting before are just relevant for the client to load new tiles from server for the given time.