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

[Christopher Schmidt]

On Fri, Sep 19, 2008 at 03:34:42PM +0100, John Westwood wrote:
> Hi Everybody,
> 
> I am attaching  a cut down version of my html, javascript and map files. On our server the EmbeddedMap.js lives in the OpenLayers directory and is used by gbhgis_openlayers.html.
> 
> The test address http://148.197.8.119/gbhgis_openlayers.html . This is just a test server so please don't tell the whole World about it! :)
> 
> There are four layers, 2 x raster (europe 1940s, WMS and MapServer) and 2 x vector / raster (Digital Chart of the World, WMS and MapServer) .

Okay, so to cut OpenLayers out of the loop:

http://148.197.8.119/cgi-bin/mapserv?map=/data/map-files/gbhgis.map&service=WMS&LAYERS=europe&FORMAT=image%2Fpng&VERSION=1.1.1&REQUEST=GetMap&STYLES=&EXCEPTIONS=application%2Fvnd.ogc.se_inimage&SRS=epsg%3A3034&BBOX=2097152,2097152,4194304,4194304&WIDTH=256&HEIGHT=256

http://148.197.8.119/cgi-bin/mapserv?map=/data/map-files/gbhgis.map&layers=europe&format=image%2Fpng&mode=map&map_imagetype=png&mapext=2097152+2097152+4194304+4194304&imgext=2097152+2097152+4194304+4194304&map_size=256+256&imgx=128&imgy=128&imgxy=256+256

The former is WMS, the latter is not-WMS.

There is a very obvious speed difference between the two.

The reason the MapServer image has its colors wrong, for the record, is
because it is using 8bit pngs instead of 24 bit pngs. My first
impression was that was the reason for the difference, but
unfortunately, 8bit gifs don't seem to fare any better.

Time for the URLs:

MapServer: real    0m0.660s
WMS: real   0m2.707s

These may help someone who knows MapServer investigate more.

Regards,
-- 
Christopher Schmidt
MetaCarta