[mapserver-users] MapCahe question -- Caching the first couple ofzoom levels

[Eichner, Andreas - SID-NLKM]

Hi James,

> like to cache the first couple of zoom levels of a very large set of
USDA
> NAIP imagery.  I've tried using the minzoom and maxzoom tags in the
> tileset,
> like this:
> <grid restricted_extent="-180 -90 180 90" minzoom="1"
> maxzoom="6">WGS84</grid>
> but once I zoom below the maxzoom value I get no imagery.

This isn't what minzoom/maxzoom are for. These switches are used in
cases where your data doesn't cover the whole grid or has a resolution
that makes it useless in high zoom levels. With them you can prevent
your cache from being filled with useless tiles.

>  I would like it
> to send the request to the source if it is beyond the maxzoom value.
Is
> there a way to do this?

Surely not. I think you misunderstood what a cache is and how it works.
You should use mapcache_seed in delete mode to throttle the cache size.
Of course it would be great if mapcache would itself gather statistics
and control the cache but that would introduce overhead and serious
problems with some cache types (especially the popular "disk" type).