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

[Nolte, Tim]

Just a note about the performance differences between the two outputs. A
24bit png is always going to take longer to render than an 8bit.
Obviously there is more detail in the 24bit thus it's going to take
longer. If you want the same 24bit look with straight MapServer you need
to make a change to your map file. You currently have set:

	MIMETYPE "image/png"

change to

	MIMETYPE "image/png; mode=24bit"

This will give you the same 24bit output between straight MapServer and
WMS. You'll also be able to compare your speeds more accurately.

- Tim

----
Timothy J Nolte - tnolte at ilpcs.com
Network Planning Engineer

iPCS Wireless, Inc.
4717 Broadmoor Ave, Suite G
Kentwood, MI 49512

Office: 616-656-5163
PCS:    616-706-2438
Fax:    616-554-6484
Web: www.ipcswirelessinc.com

-----Original Message-----
From: mapserver-users-bounces at lists.osgeo.org
[mailto:mapserver-users-bounces at lists.osgeo.org] On Behalf Of
Christopher Schmidt
Sent: Friday, September 19, 2008 11:18 AM
To: John Westwood
Cc: mapserver-users at lists.osgeo.org
Subject: Re: [mapserver-users] Using Fast CGI with MapServer to
alleviate poorperformance

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&serv
ice=WMS&LAYERS=europe&FORMAT=image%2Fpng&VERSION=1.1.1&REQUEST=GetMap&ST
YLES=&EXCEPTIONS=application%2Fvnd.ogc.se_inimage&SRS=epsg%3A3034&BBOX=2
097152,2097152,4194304,4194304&WIDTH=256&HEIGHT=256

http://148.197.8.119/cgi-bin/mapserv?map=/data/map-files/gbhgis.map&laye
rs=europe&format=image%2Fpng&mode=map&map_imagetype=png&mapext=2097152+2
097152+4194304+4194304&imgext=2097152+2097152+4194304+4194304&map_size=2
56+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
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