How to use and interpret DEBUG?

[Frank Warmerdam]

Rahkonen Jukka wrote:
> Hi,
>  
> I got interested in comparing the performance of using tiled geotiffs with overviews v.s. JPEG 2000 images.  So far I have set "DEBUG ON" in map object, named a logfile in the web object, made two layers from geotiffs and JPEG 2000s and set "DEBUG ON" for the both.
> Now when I send requests to Mapserver I get new lines to logfile, but I do not know where I should find the time that it takes to render the layer. Here is an splitted example of the lines I am getting to the log:
>  
> Mon Apr 03 13:08:52 2006,      #this is obviously date and time
> 2732,        # no idea about what this is

Jukka,

The above is likely the process id.

> 1xx.xx.xx.xxx,      # IP address of the requesting computer, I believe
> Tifspeedtest,       # name defined in the mapfile
> 3,       # no idea about this, but value seems to be always "3"

Perhaps the layer index (zero based)?

> 2539375.000000 7220000.000000 2545625.000000 7225000.000000,      # extents of the request
>      -1.000000 -1.000000, # no idea about these two either
> Geotiff ,  # names of the requested layers
> normal execution # the result
>  
>  
> Now I wonder if this is the way to do this, and if so, then what I should think about the numbers. I wonder also why I get two lines per request if I send "&mode=map&layers=Geotiff" request through browser, but nothing at all if I am sending WMS "GetMap"requests with the browser for the same layer, even if I do get the map.
>  
> Might there be some good document about using debug available? Those I have found helped me this far but not any further. 

There is a "layer render time" reported in the debug output but currently
this is controlled by the MAP debug flag, not on a per layer basis.  So
make DEBUG ON on the map and you will get some additional useful timing
information.

I'm going to change the code in 4.9-cvs so that the layer render time is
reported in debug output for layers that have debug turned on (and leaving
it so that turning on the map debug reports all layer render times).

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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