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

[Stephen Woodbridge]

On 11/25/2013 4:39 PM, Rahkonen Jukka wrote:
>
> Eichner, Andreas wrote:
>
>> Hi James,
>
>>> 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).
>
> I wouldn't be so strict. Caching only at small scale and passing requests at large scales directly towards the backend WMS is a reasonable scenario. At least we are happy with doing that with GeoWebCache and we would do the same with MapCache if it was possible. We have some frequently updated, heavy-to-render vector layers and instead of playing a game with building optimized, simplified, scale dependent group layers it is sometimes relaxing to cache the small scale tiles and let queries at large scale go directly to WMS without caching the tiles at all. Details do not show at small scales so it is not so important to refresh the cache very often. At large scales we can trust that data comes always fresh from the WMS.
>
> I am not here for advertizing GWC but sometimes it is useful to make comparisons. GWC has also implemented disk quota system -- the only supported cache type for GWC, unfortunately (one of the reasons why I use also MapCache) http://geowebcache.org/docs/current/configuration/diskquotas.html
>
> -Jukka Rahkonen-

Jukka's correct this would be a nice enhancement to mapcache. Can 
someone create an enhancement request for these features so they do not 
get lost.

Thanks,
   -Steve W