[ka-Map-users] Improving ka-map speed with non-cached WMS?

Bistrais, Bob Bob.Bistrais at maine.gov
Wed Dec 16 16:30:07 EST 2009

I'm looking into doing this, and may well be asking for further advice.

Taking it from another angle- is it possible to bypass or disable
ka-map's tiling for the image layers?  I don't mean precached vs.
nocache, what I mean is, is it possible to draw the WMS data directly
and without breaking it into tiles when ka-map renders it?  I'm asking
because this seems to be what's slowing it down.  I can draw my WMS
services in MapServer CGI mode and they're plenty fast.  Likewise, using
the same WMS services in ArcGIS or other platforms, they draw more
quickly than with ka-map.

-----Original Message-----
From: Stephen Woodbridge [mailto:woodbri at swoodbridge.com] 
Sent: Monday, December 14, 2009 6:02 PM
To: Bistrais, Bob
Cc: ka-map-users at lists.maptools.org
Subject: Re: [ka-Map-users] Improving ka-map speed with non-cached WMS?

There may be other or even better ways of dealing with this, but my
strategy has been convert all the imagery to uncompressed GTIFF data
using an internal tiled format which is the most efficient for mapserver
to access. And then to run gdaladdo on top of those. Really large files
will probably need to be tiled into smaller tiles and then built a
tileindex to stitch it all back together again. This will give you good
mapserver performance at the cost of disk space. If you data is getting
update and you need to remove old imagery and replace it, then use some
kind of directory structure to help manage that, for example if you have
a file xxx.sid create a directory xxx_sid and put the tiles in there. 
then if you need to replace xxx.sid in the future it is easy to remove
the old tiles and create new ones.


Bistrais, Bob wrote:
> We have our imagery data for the WMS services in three different
> formats- JP2, SID, and GTIFF.  I've been doing most of my testing with

> the jp2, since that's statewide orthoimagery.
> The application is presenting the WMS service in PNG24.
> A gdalinfo for one of the images gives the following:
> Driver: JP2ECW/ERMapper JPEG2000
> Files: C:\naip_07\tiles\augusta_nw.jp2 Size is 5655, 7594 Coordinate 
> System is:
> LOCAL_CS["unnamed",
>     UNIT["unknown",1]]
> Origin = (429916.000000000000000,4914197.000000000000000)
> Pixel Size = (1.000000000000000,-1.000000000000000)
> Corner Coordinates:
> Upper Left  (  429916.000, 4914197.000) Lower Left  (  429916.000, 
> 4906603.000) Upper Right (  435571.000, 4914197.000) Lower Right (  
> 435571.000, 4906603.000)
> Center      (  432743.500, 4910400.000)
> Band 1 Block=5655x1 Type=Byte, ColorInterp=Red
>   Overviews: arbitrary
> Band 2 Block=5655x1 Type=Byte, ColorInterp=Green
>   Overviews: arbitrary
> Band 3 Block=5655x1 Type=Byte, ColorInterp=Blue
>   Overviews: arbitrary
> As for the mapfile layer- do you mean the mapfile which consumes the 
> WMS (part of the ka-map app), or the file which creates the WMS 
> service?  If you mean the file which consumes the WMS, this is it:
> #NAIP Orthoimagery
>   GROUP "NAIP2007_Imagery"
>   NAME "naip2007"
>   TYPE raster
>   CONNECTION "http://myserver/wms/mapserv.exe?map=c:/wms/orthos.map&"
>     "wms_server_version" "1.1.1"
>     "wms_format" "image/png"
>     "wms_title" "NAIP"
>     "wms_abstract" "NAIP 2007 imagery"
>     "wms_srs" "EPSG:26919"
>     "wms_onlineresource" "MaineOrthos-NAIP"
>     "wms_name" "naip2007,naip10moverview,naip100moverview"
>     "queryable" "false"
>     "tile_source" "nocache"
>     "imageformat" "PNG24"
>   END
> -----Original Message-----
> From: Stephen Woodbridge [mailto:woodbri at swoodbridge.com]
> Sent: Thursday, December 10, 2009 3:14 PM
> To: Bistrais, Bob
> Cc: ka-map-users at lists.maptools.org
> Subject: Re: [ka-Map-users] Improving ka-map speed with non-cached
> Bistrais, Bob wrote:
>> I have a ka-map application which consumes WMS services, consisting 
>> of
>> various imagery layers.  We don't want to precache tiles for the WMS.
>> We also have precached tiles for vector data in the application.
>> I don't know if it matters, but the web server uses IIS, not Apache.
>> Other viewers, such as ArcGIS and Quantum GIS, can consume the same 
>> WMS services and have much faster draw times than our Ka-Map
> application.
>> We would like to see improved draw times for the WMS imagery, again, 
>> without precaching it.  Can anyone make recommendations or point me 
>> to
>> a resource discussing this?
> Bob,
> Probably need more information like:
> What your mapfile LAYER looks like?
> What format is the raster data in?
> What does gdalinfo /path/to/a/raster.file look like?
> and this is really a question about how to increase performance of 
> raster data from mapserver and might get a better response from that 
> list.
> I think there is a page(s) in mapserver docs on how to do this:
> http://www.google.com/#hl=en&source=hp&q=mapserver+raster+performance
> -Steve

More information about the ka-Map-users mailing list