Improve WMS Server Performance

[Kyle Mulka]

Hi Mapserver folks!

I have these huge (20,000px by 10,000px approx.) aerial images that I
want to figure out how to turn into a reletively speedy WMS server.

I've got all the basics down. I mean, it already works, but is really
slow. It takes up to a few minutes to generate a single image. I want it
to take less than a few seconds. It would be nice if the WMS was as
speedy as Google Maps itself, but I do caching outside the context of
mapserver to make that happen. I just want to make the WMS fast. It
would be nice if there was a completely automated way of speeding up
raster map serving. Is there?

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

I've read through the mapserver performance tips, but I'm running into a
few problems. You can follow along in section 10 on that same link.

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?

Another method I've looked into is tiling and using the tileindex
mechanism of the map file. I haven't found a good tutorial on how to
take one image and tile it into a whole bunch of smaller images all
while keeping each georeferenced correctly. It would be great if someone
could point me in the right direction.

The images are in the correct projection already fortunately. So, no
need to warp.

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

Alright... time to watch the super bowl. Enjoy the game and commercials
everyone!

--
Kyle Mulka
Computer Science in Engineering
University of Michigan
http://maps.kylemulka.com