[mapserver-users] Using Fast CGI with MapServer to alleviate poor performance

[John Westwood]

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