Improve WMS Server Performance

[Frank Warmerdam]

On 2/5/06, Kyle Mulka <mulka at umich.edu> wrote:
> I think the information I need would fit in the documentation here under
> Preprocessing-rasters:
> http://mapserver.gis.umn.edu/docs/howto/raster_data/#preprocessing-rasters

Kyle,

The short answer is that you should convert the data to an
internally tiled format, and then build overviews.

eg.
gdal_translate -co TILED=YES your.tif tiled.tif
gdaladdo tiled.tif 2 4 8 16 32 64 128 256

> One program I've looked at is gdaladdo: How do I test to make sure
> overlays are in fact being used? How do I know what levels of overlays
> to create? How do I systematically test performance so that I know what
> I'm doing to the images is a good use of my, and my computers processing
> time?

To check if the overview generation worked, run the gdalinfo
program.  After each band listed it will show the overviews
present.   If GDAL sees them, then they should be used.

> I wonder if I could reduce the quality of the images slightly to improve
> performance.

There should be no need for this.

You should really provide details of your LAYER definition,
and the gdalinfo report from the data for better feedback.

Best regards,
--
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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and watch the world go round - Rush    | Geospatial Programmer for Rent