Just FYI, I poked through some of the code, and we're using external libraries to do stream-compressing right to stdout for things like WMS or mode=map, the result being we have no idea what the content-length is at the time of header writing, and no easy way to change the procedure.
P On Wed, Sep 17, 2008 at 11:36 AM, Paul Ramsey <[EMAIL PROTECTED]> wrote: > Intriguing stuff! > > I found this generic-ish article about perl: > http://www.perlmonks.org/?node_id=83791 > > The implication is that unless/until Mapserver starts sending > Content-Length along with returned images, browsers won't do > keep-alive for us. > > More performance! > > P. > > On Wed, Sep 17, 2008 at 10:26 AM, Jim Klassen > <[EMAIL PROTECTED]> wrote: >> I have found there is a fairly large overhead inherent in the HTTP request >> (per tile) especially if the network round trip times are an issue. Using >> HTTP keep-alive helped a lot with this. >> >> Awhile ago we did some tests at the city when we were looking to go to a >> tiled interface. What we found was along the lines of a 100x100px tile >> request takes much more than 1/4 of the time of a 200x200px request so the >> overall map load time was slowed by using more tiles when getting the tiles >> from mapserver. This would probably be different if we had used a tilecache. >> In the end we found not tiling (a.k.a. 1 tile per map) worked best for us >> from a speed/flexibility focus. >> >> JimK >> >>>>> "Paul Ramsey" <[EMAIL PROTECTED]> 09/17/08 11:14 AM >>> >> John, >> >> The idea that CGI is naturally a much slower situation than a >> long-running process is a bit of a red herring in the case of >> Mapserver, and I say that as someone who is anal retentive about these >> things. Unless your Mapserver installation has some naturally latent >> components (database connections, primarily) you'll find that moving >> from CGI to FastCGI is worth about 15ms per request. >> >> On Wed, Sep 17, 2008 at 8:40 AM, John Westwood <[EMAIL PROTECTED]> wrote: >> >>> The reason I am trying to get MapServer to work with fast_cgi is because I >>> am experiencing poor performance with OpenLayers. I believe that OpenLayers >>> starts a new MapServer instance for each tile request, thus causing an >>> unnecessary overhead. Am I correct? >> >> Yes and no. If you are experiencing noticeably poor performance (you >> can actually *see* it being slow) the only place that the CGI overhead >> could be the cause is if you're connecting to Oracle or SDE for some >> of your layers. If that's not the case, look elsewhere first, the very >> small gains you will receive from moving to FastCGI will not change >> your underlying problem. >> >> Paul >> _______________________________________________ >> mapserver-users mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/mapserver-users >> >> > _______________________________________________ mapserver-users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/mapserver-users
