[mapserver-users] performance test of ECW tiles

[Thorsten Fischer]

On Thu, 2003-06-19 at 14:37, bartvde at xs4all.nl wrote:
Hi list,
> 
> I have done a small performance test with an ECW file of 4,5 Gb. I did
> my
> test with the Microsoft Web Application Stress tool for 1 minute. I 
> have
> done my test in two configurations:
[ snip ]

Did you show the whole set every time? Tiles, like indices, do not make
too much sense if you show all the data at the same time.

Webmapping application rule number one: Never Show Everything You Got :)

> I also did not realize the big part DOWNLOAD takes in webmapping
> performance. The gif files created are around 80 Kb so download will
> be in
> the best case around 2 seconds. This is 4 times the time mapserver
> needs to create the image.

Plus the latency time for network communication and the time it takes to
show the resulting image in the browser, especially if the client is on
the same machine for this test. Plus accessing the file system for temp
images of course which should not be underestimated, especially if you
are producing truecolor thingies in 4.0 ...

There are quite a lot of factors that one needs to keep an eye on. They
are small, but they do add up.

That has nothing to do with ecw or image tiling anymore, of course ;)


hth,

thorsten