[mapserver-users] performance test of ECW tiles

[Bart van den Eijnden]

Hi Thorsten,

yes I did show only a small part of the image for my test.

You're right, with the Microsoft Web Application Stress tool the client 
(IE) is on the same machine. My data was on a SCSI drive in the server, so 
no network transport.

I used the WMS interface for my test. But by using the WMS interface no 
temp files are written, or am I mistaken? I thought everything was streamed 
to the client.

Best regards,
Bart

On 22 Jun 2003 20:26:16 +0200, Thorsten Fischer <thfischer at mapmedia.de> 
wrote:

> 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
>
>
>



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