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

[Guillaume Sueur]

I guess that wms makes a reprojection job as the request comes with an
EPSG code and the map projection is set by a proj string. Even if they
are equivalent, can MapServer know that and forget about reprojection ?

The cgi is rather straight forward as no EPSG is required. As the layers
don't have PROJECTION blocks, they are drawn straight forward.

my 2 cents.

Guillaume

Christopher Schmidt a écrit :
> 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,