Daniel Morissette dmorissette at DMSOLUTIONS.CA
Wed Feb 16 17:30:02 EST 2005

Bart van den Eijnden wrote:
> What else is on the lists?

Personally I find that we've got a quite complete set of features, so my
personal wishes would go towards improving what's there instead of
adding new features:

- Performance tuning

- Security audits

- Easy installation. We've started work on that with MS4W and FGS, but
there is still lots of work to do.

- Any tools that can make it easier for new users to get up to speed
with the software quickly.

And finally, one new feature idea:

- Ability to work in pre-canned-maps-mode:

I'm sure you've all seen Google and its (obviously) pre-canned map
tiles. Well, back in 1999, before we found MapServer, that's the
direction in which we were going with webmapping at DMSG and Google
reminded me of this idea a few weeks ago. This idea was inspired from
what a few other sites were doing at the time so it's not new and I
can't take credit for inventing it. But then we found MapServer and it's
performance and robustness was just so impressive (compared to the
alternatives of those days) that we dropped this idea of pre-generating
the maps since that was not necessary any more for the types of sites
that we were working on.

I think that one of MapServer's next challenges is to be able to serve
the needs of the high traffic sites that produce tens or hundreds of
millions of maps per month, always based on the same *static* street
data. If you generate the maps on the fly with a relatively complex
mapfile based on vector data with street labelling, etc, then you can
only get a few million maps per month per CPU. Imagine the server farm
you'd need for 100 million maps.

OTOH, since the street data is static, you could pregenerate the maps as
tiled rasters for a number of preset scales, configure one raster layer
per scale, add a little bit of logic in MapServer to force it to use a
discrete number of scales and you're running. You can still plot points
on top of the map, do queries, or do anything else that MapServer was
doing before... you just don't render the static street data all the time.

That would require lots of disk space in some cases, but disk space is
cheap as I keep being reminded... and for the cases where it's not
practical to pregenerate all the maps, I've also got some ideas for a
hybrid mode where the vector layers kick in if no raster tile was found
for the current map area.

Combine that with a fastcgi (or persistent mapscript) that preloads the
mapfile and the raster tileindex in memory and you'd be flying!

  Daniel Morissette               dmorissette at dmsolutions.ca
  DM Solutions Group              http://www.dmsolutions.ca/

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