A couple of issues / tips we have found in this sort of scenario. 1) Edit your epsg file to contain only the projections you want - this can make a big difference - presumably because its doind a slow string search each time 2) If using OpenLayers (or google maps etc) - the tiling sends multiple requests to the WMS server. If you are using IE in particular - this restricts you to 2 concurent threads to any one server - mean9ing that your (say) 16 tile requests can only be processed 2 at a time. Firefox has a similar restriction by default - but you can override it. You can see this at work using Firefox with a tool like firebug.
We foun it was much much quicker if you can change yout application to request a single WMS tile for the whol map rather than individual 256x256 tiles. Obviously this may have implications if you were trying to cache tiles etc - but if not its massively quicker HTH James On Wed, Sep 17, 2008 at 4:40 PM, John Westwood <[EMAIL PROTECTED]> wrote: > Hi, > > I am trying to use fast_cgi with MapServer, specifically mod_fcgid on SLES > 10.2. > > I have mod_fcgid correctly set up within Apache because it works with another > FCGI application (IIPImage). > > I have successfully compiled MapServer 5.2 with fast_cgi support. I used this > page to help me: > http://mapserver.gis.umn.edu/docs/howto/fastcgi > > However, when I try to use MapServer with mod_fcgid I receive the following > error: > > The server encountered an internal error and was unable to complete your > request > Error message: Premature end of script headers: mapserv > > I am really lost as to what the problem could be; the non fast_cgi version of > MapServer that I compiled worked fine. Perhaps it is something to do with > setting the LD_LIBRARY_PATH in the mod_fcgid.conf file? > > At the moment I have it set as follows: > > DefaultInitEnv LD_LIBRARY_PATH "/usr/lib:/usr/local/lib:/usr/lib/postgresql" > > > 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? > > I will also be using Tilecache, but my experiments have also found this to be > slow. It is currently set up to use mod_python. The hardware we are running > on is a dual quad core (eight cores in total) Xeon . So it shouldn't be slow! > > I would greatly appreciate any help on getting MapServer to work with > fast_cgi . I would also welcome any comments regarding performance issues > with OpenLayers / MapServer / Tilecache . > > Thanks very much, > > John Westwood > > Great Britain Historical GIS Project > > _______________________________________________ > mapserver-users mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/mapserver-users > -- Dr James Perrins exeGesIS SDM Ltd Great House Barn New Street, Talgarth Powys LD3 0AH. Direct Line: 01646 686650 Tel: 01874 711145 Fax: 01874 711156 Email: [EMAIL PROTECTED] This E-mail and any files transmitted with it are private and intended solely for the use of the individual or entity to whom they are addressed. If you are not the intended recipient, the E-mail and any files have been transmitted to you in error and any copying, distribution or other use of the information contained in them is strictly prohibited. Nothing in this E-mail message amounts to a contractual or other legal commitment on the part of exeGesIS SDM Ltd unless confirmed by a signed communication. exeGesIS SDM Ltd will make every effort to keep its network free of viruses. However, the recipient of this message will need to scan this message, and any attachments, for viruses, as exeGesIS SDM Ltd can take no responsibility for any computer virus that might be transferred by this e-mail. _______________________________________________ mapserver-users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/mapserver-users
