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I have edited a part of the coastline. The tags look good to me but the Mapnik map still uses the old coastline. Is there something else to do?

asked 16 Jul '10, 22:40

ChrisH's gravatar image

ChrisH
3.8k124061
accept rate: 13%

edited 04 Jul '11, 16:50

katpatuka's gravatar image

katpatuka
756101930

-1

Does the same timing apply to railway lines modifications, before one can see them in the main map?

(28 Apr '11, 07:53) averageman
4

No. coastlines are a special case. Other features render in the usual time frame, so if they don't appear within a day, check that your browser cache has been refreshed and then check that your tags don't have any errors.

(28 Apr '11, 15:03) ChrisH

As explained on the OSM Wiki, the coastlines used by the main Mapnik map come from shapefiles which are generated every few weeks. This means you will have to wait a while for your changes to become visible.

The reason for this is that building the landmass polygons from coastlines is a relatively complex operation, and tile rendering performance would degrade massively if one would attempt to do this "on the fly" when tiles are rendered.

If you want to find out when the coastline was last processed, check the time stamp on the file http://tile.openstreetmap.org/shoreline_300.tar.bz2 file, for example by typing, on a Linux system,

wget --server-response --spider http://tile.openstreetmap.org/shoreline_300.tar.bz2

Then check the Last-Modified header in the response:

HTTP/1.0 200 OK
Date: Fri, 15 Oct 2010 17:27:52 GMT
Server: Apache/2.2.8 (Ubuntu)
***Last-Modified: Fri, 24 Sep 2010 23:44:09 GMT***
ETag: "2ae2f4-2f4e0e1-49109f476c440"
Accept-Ranges: bytes
Content-Length: 49602785
Content-Type: application/x-bzip2
[...]

Note that even after the coastline has been processed into a shape file, that will only show up on the map when the relevant tiles have been re-rendered.

link

answered 16 Jul '10, 22:52

Frederik%20Ramm's gravatar image

Frederik Ramm
38.2k48372605
accept rate: 22%

edited 05 Feb '11, 00:02

Well Frederik, when I asked this question four months ago,

https://help.openstreetmap.org/questions/20936/how-long-will-it-take-for-my-coastline-edits-to-show-up

you directed me to this answer. Problem is, my coastline edits have still not shown up at any zoom level.

At what point should we begin to suspect a problem causing tiles to take an inordinately long time to re-render?

(14 Jul '13, 01:36) gpspilot1
1

@gpspilot1: Simply looking up the last modified date of the coast line (with the command Frederik suggests) results in: "Last-Modified: Thu, 07 Feb 2013". The last coast line update was on 7th February 2013. Same day for the processed_p.tar.bz2 which is used for higher zoom levels according to the wiki page.

(14 Jul '13, 03:22) aseerel4c26

This is a frequently repeated question. Unfortunately, the referred answers are several years old and this may slightly be confusing. What we/I know today is that the vector Planet_land/_sea, scale/zoom levels, (none-trivial)tiles generation and the change detection could be done in several hours. But what we/I don't know is how to help, even if we/I want to help. Thanks!

(14 Jul '13, 07:40) sanser
1

Updates are now daily.

(24 Sep '13, 20:07) Firefishy

Note also that on the highest zoom levels the new coastline may show up only months later. You can see an example of this (at least as of writing this) at http://www.openstreetmap.org/?lat=18.108985&lon=-73.943095&zoom=18&layers=M vs. http://www.openstreetmap.org/?lat=18.108985&lon=-73.943095&zoom=17&layers=M -- The zoom level 18 still doesn't show my editing of the coastline even though it's been nearly half a year from editing and I've viewed the location (with zoom 18) a number of times after (which to my understanding is sometimes needed for new tiles to be created).

Maybe someone can clarify this but it really can take months for the higher level modifications to render.

Patience.

link

answered 28 Apr '11, 01:44

jaakkoh's gravatar image

jaakkoh
3733711
accept rate: 0%

Coastlines are now updated daily.

Check http://tile.openstreetmap.org/cgi-bin/debug to see when the file land-polygons-split-3857.zip (coastlines) was last updated.

link
This answer is marked "community wiki".

answered 24 Sep '13, 20:06

Firefishy's gravatar image

Firefishy
1.0k52847
accept rate: 30%

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Asked: 16 Jul '10, 22:40

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Last updated: 24 Sep '13, 20:07

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