[OSM-talk] Old data being cached too long

[Matias D'Ambrosio]

On Saturday 18 October 2008 05:32:24 you wrote:
> I've just grabbed a mapnik tile at random, and these are the headers
> sent out with it:
>
> Date: Sat, 18 Oct 2008 07:20:05 GMT
> Server: Apache/2.2.4 (Ubuntu)
> Etag: "cb5563ba81dda2fd9bf27cba5a41164f"
> Content-Length: 7149
> Cache-Control: max-age=374906
> Expires: Wed, 22 Oct 2008 15:28:32 GMT
> Content-Type: image/png
>
> Therefore, an ISP's transparent proxy should fetch a new version (or
> the same one again) after 374906 seconds, or 4.33 days.
>
> Some ISP's ignore the cache times in their transparent proxies and
> therefore should be shouted at. Are any of the tiles you're viewing
> older than 4 days? Tiles at home tiles are every day, as I recall, and
> therefore three render cycles could be within the timescale?
>
 Yes, quite older, looks like some yelling is in order. Not that I have much 
hope for my ISP, I may have to have a script to reload all tiles in the area 
I'm interested once a week if they don't fix it.

> a T at H headers set:
> Date: Sat, 18 Oct 2008 07:27:36 GMT
> Server: Apache
> Cache-Control: max-age=10800
> Last-Modified: Fri, 17 Oct 2008 10:47:20 GMT
> Content-Length: 16457
> Content-Type: image/png
>
> Which should expire after 3 hours. Notably, this doesn't have a
> Expires: header, which means (theoretically) it could get kept longer
> as various levels of proxy/cache grab it from each other...
> Maybe this would help?
>
 I guess it should expire, but it doesn't affect me right now, I think. I 
mostly use mapnik, anyway.

> It should be that holding down control and pressing refresh in your
> browser should request a new version and not accept cached versions,
> but I don't know if this matters to javascript or ISP proxies...
>
 Me neither, in any case, it's not practical to refresh each tile.
 Thank you very much for the info, now it's time to call them.