performance slows down when compiled with gdal

[Frank Warmerdam]

H. Porath wrote:
> This "fat" mapserver binary needs more than three seconds for the same request although i am still requesting png. 
> Has anyone an idea why this is so and how i can fix it? Is it possible that the mapserver tries to read the png files with the gdal driver? As far as i know the gdal driver ist much slower than the gd driver. So i added an "outputformat" directive to my mapfile:
>     OUTPUTFORMAT
>       NAME png
>       DRIVER "GD/PNG"
>       MIMETYPE "image/png"
>       IMAGEMODE PC256
>       EXTENSION "png"
>    END
> 
> The problem is that this directive obviously only has effect on writing of png. Does anyone know if i can force mapserver to use the GD library for reading of png (and jpeg)?
> 
> Some additional infos:
> -gdal 1.3.1 with support of mrsid, dynamically linked
> -the raster data is in the same coordinate system as the wms request
> -the raster data is an 8bit png (9 kb of size) georeferenced in a worldfile

Holger,

How long does a "mapserv -v" report take?  I vaguely suspect you are
seeing a high cost to loading all the shared libraries, perhaps because some
of the shared libraries are having to be link edited into a new location.
I know this used to be an issue on Solaris (many years ago) if the -fPIC
flag was missed during compiles.  If mapserv -v takes 1-2 seconds then you
will know that the issue is a "startup cost" issue.

I don't see any reason why using GDAL to render from a small PNG file should
be slow.

Best regards,
-- 
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | President OSGF, http://osgeo.org