Hi,
following up a discussion I had with Arne in Sydney today I
checked how much the compression level settings in PNG affected
the outcome of the FOSS4G benchmark and confirmed the difference
was significant (10-20% on the labelling test).
In particular on my machine I measured up to 15.2 req/s with
the current compression level, and up to 16.4 res/s with a more
relaxed value that, to my surprise, did not really change much
the size of the output.
Pity I did not pay attention before the shootout, I was distracted
by unrelated work unfortunately. And yes, next year I'll try to
involve more people into the effort, and earlier, apologies for
mis-managing it.
Anyways, I've attached to http://jira.codehaus.org/browse/GEOS-3599
a patch that changes the default value of the compression
to a more relaxed value and also allows the admin to tweak
that value.
The compression is between 0 and 100, the defaults are 25
now. Looking at it it seems values between 0 and 20 show
huge changes in the output side, past that the change in
output size is small but the change in effort big.
It is something I'll have to document.
One thing that left me wondering is where and how set the
defaults. I did so in the WMS facade and in the UI, wondering
if there is a better and central place to enforce defaults thought.
I was thinking persistence (while loading the WMS metadata
map) but I'm not sure where to put my hands. Suggestions?
Cheers
Andrea
--
Andrea Aime
OpenGeo - http://opengeo.org
Expert service straight from the developers.
Took a look over the patch and it looks good to me.
Andrea Aime wrote:
Hi,
following up a discussion I had with Arne in Sydney today I
checked how much the compression level settings in PNG affected
the outcome of the FOSS4G benchmark and confirmed the difference
was significant (10-20% on the labelling test).
In particular on my machine I measured up to 15.2 req/s with
the current compression level, and up to 16.4 res/s with a more
relaxed value that, to my surprise, did not really change much
the size of the output.
Pity I did not pay attention before the shootout, I was distracted
by unrelated work unfortunately. And yes, next year I'll try to
involve more people into the effort, and earlier, apologies for
mis-managing it.
Anyways, I've attached to http://jira.codehaus.org/browse/GEOS-3599
a patch that changes the default value of the compression
to a more relaxed value and also allows the admin to tweak
that value.
The compression is between 0 and 100, the defaults are 25
now. Looking at it it seems values between 0 and 20 show
huge changes in the output side, past that the change in
output size is small but the change in effort big.
It is something I'll have to document.
One thing that left me wondering is where and how set the
defaults. I did so in the WMS facade and in the UI, wondering
if there is a better and central place to enforce defaults thought.
I was thinking persistence (while loading the WMS metadata
map) but I'm not sure where to put my hands. Suggestions?
Cheers
Andrea
--
Justin Deoliveira
OpenGeo - http://opengeo.org
Enterprise support for open source geospatial.