Hi Juliana, On 12 Mar 2011, at 00:20, Juliana wrote: > To know that that time has past Virtuoso reads HTTP headers and uses the > "Date", "ETag", "Expires", "Last-Modified", > "Cache-Control" and "Pragma: no-cache" fields to calculate when the resource > should be reloaded. > > The problem I'm having is that data is always got from cache, and I think > this happens because one or more of these tags are missing > in the http header of D2R response.
Here's the header of a typical D2R SPARQL response: HTTP/1.1 200 OK Date: Sat, 12 Mar 2011 18:12:58 GMT Server: Jetty(6.1.10) Cache-Control: no-cache Pragma: no-cache X-Joseki-Server: Joseki-3.2 Content-Type: application/sparql-results+xml So the only headers not present are ETag, Expires and Last-Modified. To send these headers one would have to know when the relevant records in the DB have been last changed, and when they are likely to change next (for Expires). D2R has no knowledge of that, so it can't set those headers. Note in particular the presence of the various no-cache values, which actually indicate that query responses should not be cached. So I'm not convinced that there's anything that we can change in D2R to resolve your issue. Best, Richard > So, what I would like to ask you is if there is a way to force that the > response given by D2R includes these properties in the header, > so that updated data can be got after the specified time has past. > > Thank you very much. > > Regards, > Juliana Quiñones > ------------------------------------------------------------------------------ > Colocation vs. Managed Hosting > A question and answer guide to determining the best fit > for your organization - today and in the future. > http://p.sf.net/sfu/internap-sfd2d_______________________________________________ > d2rq-map-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/d2rq-map-devel ------------------------------------------------------------------------------ Colocation vs. Managed Hosting A question and answer guide to determining the best fit for your organization - today and in the future. http://p.sf.net/sfu/internap-sfd2d _______________________________________________ d2rq-map-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/d2rq-map-devel
