Re: [mapserver-users] Using Fast CGI with MapServer to alleviatepoor performance

[Stephen Woodbridge]

Has anyone thought of using SQLite internally in mapserver for say 
storing the EPSG file in an indexed table for faster access. We could 
have a utility that would read the epsg text file and create the table 
for maintenance purposes.

SQLite has some other interesting possibilities if you combine it with 
SpatiaLite which has most all of PostGIS support so you could have the 
OpenSource Equivalent GeoDatabase, but that probably another thread.

-Steve W

Guillaume Sueur wrote:
doesn't mapserver have to scan the whole epsg file to find the matching
 epsg - proj pair ?

Steve Lime a écrit :
This shouldn't be the case, there are tests in the main API code to test
projections of the map
against layers to avoid this. I suspect it's projection related
though...

Steve

On 9/19/2008 at 11:19 AM, in message
<[EMAIL PROTECTED]>,
Guillaume Sueur <[EMAIL PROTECTED]> wrote:
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&L

AYERS=europe&FORMAT=image%2Fpng&VERSION=1.1.1&REQUEST=GetMap&STYLES=&EXCEPTIONS=ap
plication%2Fvnd.ogc.se_inimage&SRS=epsg%3A3034&BBOX=2097152,2097152,4194304,419
4304&WIDTH=256&HEIGHT=256
http://148.197.8.119/cgi-bin/mapserv?map=/data/map-files/gbhgis.map&layers=europ

e&format=image%2Fpng&mode=map&map_imagetype=png&mapext=2097152+2097152+4194304+41
94304&imgext=2097152+2097152+4194304+4194304&map_size=256+256&imgx=128&imgy=128&im
gxy=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,
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