[mapserver-dev] mapserver 5.4 beta performance test

[Paul Ramsey]

On Mar 31, 2009, at 8:57 AM, Guillaume Sueur wrote:

> Thanks for this piece of info Paul. I'm a bit disappointed by the  
> nearly
> 10 speed factor difference between PostGIS layer and shapefile layer  
> on
> that large dataset. I did my test on my personnal PC though. I will  
> test
> that on a fast server as well.

I'm not too disappointed. Retrieving the entirety of a large table is  
degenerate case. As long as the performance remains acceptable in the  
"drawing a few thousand features" case, I'm OK with it.  Databases are  
optimized for random access, not bulk access.

P.

>
>
> Best regards,
>
> Guillaume
>
> Paul Ramsey a écrit :
>> I moved from a binary to a text cursor for 5.4, which has a
>> performance penalty. It also has a huge code simplicity bonus,  
>> which I
>> judged worth it (binary cursors have to be managed within transaction
>> blocks, which adds a surprisingly high complexity overhead). I  
>> changed
>> the text encoding during the code sprint, so if your test is using
>> code from before then, the next release should be slightly faster,
>> though still probably slower than the 5.2 code.
>>
>> P.
>>
>> On Tue, Mar 31, 2009 at 7:49 AM, Guillaume Sueur
>> <no-reply at neogeo-online.net> wrote:
>>> Another weird point :
>>>
>>> If I ask for the whole dataset, 5.4 is slower than 5.2 (11 and 9  
>>> secs)
>>> but with a filter on an indexed field, I get 0.607s with 5.4 and  
>>> 2.3s
>>> with 5.2.
>>>
>>> If I use the shapefile of the data I get :
>>> whole dataset :
>>> 5.4 : 1s
>>> 5.2 : 1s
>>> with a filter on :
>>> 5.4 : 0.76s
>>> 5.2 : 0.76s
>>>
>>> So, as far as I can tell, shapefile still goes much faster than  
>>> PostGIS
>>> layers, with various differences between 5.2 and 5.4
>>> 5.2 and 5.4 are equal when dealing with shapefiles.
>>>
>>> Does this sound ok for you devs ?
>>>
>>> Regards
>>>
>>> Guillaume
>>>
>>>
>>> Guillaume Sueur a écrit :
>>>> Hi,
>>>>
>>>> I'd like to share some strange results I've got back when testing
>>>> mapserver 5.4 beta on a huge streets postgis layer.
>>>>
>>>> here are the tests :
>>>> 5.4 beta DEBUG ON -----------------------------------------------
>>>> time /usr/local/src/mapserver-5.4.0-beta3/shp2img -m test.map
>>>> -map_debug 5 -o test.png
>>>> [Tue Mar 31 15:49:15 2009].935351 msDrawMap(): Layer 0 (streets),  
>>>> 1.617s
>>>> [Tue Mar 31 15:49:15 2009].935551 msDrawMap(): Drawing Label  
>>>> Cache, 0.000s
>>>> [Tue Mar 31 15:49:15 2009].935603 msDrawMap() total time: 1.619s
>>>> [Tue Mar 31 15:49:16 2009].24176 msSaveImage() total time: 0.089s
>>>> [Tue Mar 31 15:49:16 2009].24347 msFreeMap(): freeing map at  
>>>> 0x818f8e0.
>>>>
>>>> real  0m1.719s
>>>> user  0m0.284s
>>>> sys   0m0.028s
>>>>
>>>> 5.4 BETA DEBUG OFF ---------------------------------------------
>>>> time /usr/local/src/mapserver-5.4.0-beta3/shp2img -m test.map -o  
>>>> test.png
>>>>
>>>> real  0m1.994s
>>>> user  0m0.408s
>>>> sys   0m0.020s
>>>>
>>>> as you can see it goes faster with debug ON (tested several times)
>>>>
>>>> if I try it back with mapserver 5.2 I get :
>>>>
>>>> 5.2 DEBUG ON -----------------------------------------------
>>>> time /usr/local/src/mapserver-5.2.0/shp2img -m test.map - 
>>>> map_debug 5 -o
>>>> test.png
>>>> [Tue Mar 31 15:52:01 2009].891334 msDrawMap(): Layer 0 (streets),  
>>>> 1.434s
>>>> [Tue Mar 31 15:52:01 2009].891549 msDrawMap(): Drawing Label  
>>>> Cache, 0.000s
>>>> [Tue Mar 31 15:52:01 2009].891603 msDrawMap() total time: 1.437s
>>>> [Tue Mar 31 15:52:02 2009].43083 msSaveImage() total time: 0.151s
>>>> [Tue Mar 31 15:52:02 2009].43240 msFreeMap(): freeing map at  
>>>> 0x81878e0.
>>>>
>>>> real  0m1.599s
>>>> user  0m0.268s
>>>> sys   0m0.016s
>>>>
>>>> 5.2 DEBUG OFF  -----------------------------------------------
>>>>
>>>> time /usr/local/src/mapserver-5.2.0/shp2img -m test.map -o test.png
>>>>
>>>> real  0m1.481s
>>>> user  0m0.296s
>>>> sys   0m0.008s
>>>>
>>>>
>>>> So the 5.4beta seems definitely slower than 5.2, and goes even  
>>>> slower
>>>> when DEBUG is off.
>>>>
>>>> Is there a special setting activated by default on beta releases  
>>>> which
>>>> could explain that ?
>>>>
>>>> Best regards
>>>>
>>>> Guillaume
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> mapserver-dev mailing list
>>>> mapserver-dev at lists.osgeo.org
>>>> http://lists.osgeo.org/mailman/listinfo/mapserver-dev
>>>>
>>>>
>>> _______________________________________________
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>>>
>>
>>


--
Paul Ramsey
OpenGeo - http://opengeo.org
Food, survival gear, weapons, shelter, PostGIS. Go!