[mapserver-dev] Cache-control in WMS Requests

[Sean Gillies]

Christopher Schmidt wrote:
> On Tue, Mar 18, 2008 at 10:43:50AM -0700, Paul Ramsey wrote:
>> For reasons of "user ease" having things like this configured in one
>> place is handy ("how do I improve my Openlayers performance?" "add
>> this one line"). I'm going to test this morning though, and see how
>> much difference this one header makes to browsers in terms of actual
>> caching behavior 
> 
> It should be significant, based on my experience.
> 
>> (they might ignore the header because the URL is "cgi-shaped", etc,
>> etc).
> 
> I've never had that problem.
> 
>> Unfortunately the rest of the headers that affect caching (last
>> modified, etag, etc) are probably off the table, since they can't be
>> tracked properly in a dynamic environment.
> 
> I'm not sure I agree with this. Perhaps by default you would want such
> tracking 'off', but certainly one could have a setting which says "use
> the last modified time of the mapfile for these things", and use the
> etag/last-modified for that. (Admittedly, it requires more work.) 
> 
> Regards,

Doesn't WMS have something "better" than ETag or Last-Modified? Update
sequence?

Sean