[Freegis-list] compressing GML

[michael gould]

Hi all,

 

I am curious if people out there have made any progress in the area of
compression/decompression of GML for transport. ( I recall a while back
someone complaining of GML’s verbosity, and others replying that’s ok, you
can always gZip it
)

 

Our case: my people are testing all sorts of permutations of clients seeking
data from WMS and WFS, and are making a series of Excel charts documenting
what happens in each case, varying the number of simultaneous users (they
generate multiple user threads to attack the server), the server
characteristics (RAM, O.S.), and the data size as retrieved. Among other
things they are finding that retrieving a several megabyte GML as generated
by MapServer’s WFS, is not possible under the generous 10 minute timeout
limitation
with client and server on machines in the same laboratory and
connected via 100 Mbit switch. However, when they fast-Zip a 100+ MB file
(manually) they find that it is reduced to about 5MB. So it would seem to be
a good idea for the server to do this, under certain circumstances.

 

So, who is doing this? Is there code available?  How are we on the issue of
GML compression? Or on the occasional use of GML-binary?

 

Ciao,

 

 

-----------

Michael Gould

Department of Information Systems (LSI)

Universitat Jaume I, 12071 Castellón Spain

E-mail: gould (at) lsi.uji.es

 <http://www.mgould.com> http://www.mgould.com

 <http://www.geoinfo.uji.es> http://www.geoinfo.uji.es

 

 

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