[Benchmarking] Chat about the load testing setup

[Frank Warmerdam]

Daniel Morissette wrote:
> Andrea Aime wrote:
>> Hi,
>> me and Frank had a quick chat about how to setup the
>> test loading scripts against the ECW layers (but, more
>> in general, against any layer we're going to test).
>>
> 
> Thanks for sharing. BTW, where did this chat happen? As a IRC channel 
> been created just for this?

Folks,

Andrea just opened a private chat with me.  I'd think #osgeo would be
a decent place to meet if needed (or #mapserver or #geoserver possibly).

I have attached a preliminary version of a script to generate BBOXes.

  Usage: wms_request.py [-count n] [-region minx miny maxx maxy]
                      [-minres minres] [-maxres maxres]
                      [-maxsize width height] [-minsize width height]

The region is the georeferenced area.
The -maxsize and -minsize control the limits of WIDTH and HEIGHT.
The -maxres and -minres are the minimum and maximum resolution
described as a pixel size in the coordinates of the datasource.

I generate the bbox rectangles by randomly selecting a center point
in the region, and then selecting a resolution on a log scale between
minres and maxres (this should favor the high resolution end of the scale).
I then produce a bbox and test if it is entirely in the region - if not
I discard and restart.

So, for instance, the following:

wms_request.py -count 100 -region -180 -90 180 90 -minres 0.0042 -maxres 0.5

produces sort of reasonable requests on a world wide 4326 image like ours.

The default min/max sizes are 128x128 to 1024x768.

Best regards,
-- 
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent

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