[mapserver-dev] News on MapServer SLD and MapCache

[Jeff McKenna]

Salut Jérome,

Great idea to create a MapCache performance wiki page, or a section on 
the wiki for MapCache performance tips, where users can place their 
notes and hints to increase performance.  I find this works well, you/we 
just have to send reminders to the -users list to keep the page updated.

I personally like the use of RFC documents, mostly because users can 
read the exact logic behind the improvements (and often the best 
documentation for the feature exists at the RFC level).  RFCs also 
include example syntax, which users also like to see.  (sometimes our 
official docs are more precise and lack space for longer examples)

I'm having a hard time understanding how a dimension value would be a 
security concern, but I'm sure that others will have better feedback 
here for you.

Thanks for your effort on MapCache Jérome!

-jeff



On 2019-12-17 5:18 AM, jbo-ads wrote:
> Hi all,
> 
> I would like to apologize for not having been active on MapServer SLD 
> these months. I am busy on more urgent activities from my client, mainly 
> related to MapCache performance. I hope to deliver a synthesis on the 
> form of a wiki page (which to my surprise has not been initiated yet on 
> MapCache).
> 
> On this side, I am fixing some bugs and adding configurable features to 
> better control how MapCache retrieves and assembles tiles from its 
> caches depending on each situation.
> 
> I am also developing feature requests that arise in the broader context 
> of these activities.
> 
> The first one is about a cache structure involving multi-SQLite caches 
> organized in multiple pyramids: one single pyramid from zoom levels 0 to 
> 7, then as many pyramids as tiles at zoom level 8. Each of these 
> pyramids starts with one tile at zoom level 8, then four tiles at zoom 
> level 9 and so on. Of course the top zoom level value is configurable. I 
> like to name this cache structure "Z-top". My question is: Do you think 
> it deserves a RFC?
> 
> The second one is about allowed values in MapCache implementation of 
> WMS/WMTS dimensions. Currently, dimensions values are sanitized so that 
> '.' (dot) and '/' (slash) characters are replaced by '#' (is it sharp or 
> hash in english?). However my client (and others I've heard of) would 
> like to use file paths as dimension values in order to store cache 
> locations without being constrained to put them all in a single 
> directory. I feel a bit reluctant about this because I suspect this 
> change would introduce a security hole in MapCache, by potentially 
> giving access to server's filesystem. I would like to open the 
> discussion with you about how to provide this feature without 
> compromising security.
> 
> Jérome.
> 
>