[mapserver-dev] More Performance
pramsey at cleverelephant.ca
Mon May 12 15:17:03 EDT 2008
I don't have an environment, I'm just taking the info from Andrea. The
effect of loading a font is definitely noticeable... my
small-map-on-large-file (no labels) case draws faster than the simple
draw-50-states (state name labels) case, and the difference is the
font loading. The curl init overhead is there too, though I see now
drilling lower into it that it is specific to curl-with-ssl,
initializing the SSL. Regardless, something that is removable for a
few ms gain.
No details on the use cases, I'm afraid. Andrea sent me his test map,
but it's really just a simple shapes with colors and labels, no
selectivity case. He is trying to build a performance testing
framework that he can use to regress geoserver over time, to ensure
new development doesn't destroy performance. It's all HTTP based, so
we could use the same infrastructure.
On Mon, May 12, 2008 at 12:07 PM, Steve Lime <Steve.Lime at dnr.state.mn.us> wrote:
> Do you have a GeoServer/MapServer test environment setup? I'd really like to get one
> in place. It's impossible to know how fast or slow MapServer is with out it. I'm assuming
> Andrea has one since he's still testing head-to-head.
> Are the various use cases detailed some place?
> Thanks for the Shark tip, hadn't heard of that one.
>>>> On 5/12/2008 at 1:50 PM, in message
> <30fe546d0805121150t765a77bl80ecc5ab3092070d at mail.gmail.com>, "Paul Ramsey"
> <pramsey at cleverelephant.ca> wrote:
>> Andrea Aime pointed out that Geoserver is still running about 3-times
>> as fast as Mapserver in some use cases, which has prompted me to
>> discover Shark (note to developers on OS/X, learn to run Shark).
>> Among the things Shark tells me is that the epsg configuration file
>> remains the biggest (avoidable, but non-obvious) performance issue,
>> potentially hogging huge amounts of resources, since the projections
>> are loaded even for layers that aren't being rendered. Even worse,
>> it's a performance issue that fcgi doesn't fix, since the loading
>> happens in msLoadMap.
>> Another thing Shark tells me is that we are burning resources in
>> curl_global_init (called from msHTTPInit via msHTTPInitRequestObj)
>> even when there are no WMS or WFS layers defined. This is eating
>> about 5% of the total cycles, on a fairly well-tuned map file, and
>> could be fixed.
>> Finally, the biggest single resource muncher in this small-easy-map
>> case is loading the font file. This could be an artefact of the OS/X
>> font loading, or it could be generic. It looks like gd has a font
>> cache, so perhaps this goes away in FCGI. I guess that should be my
>> next test, because if it doesn't go away it's a big win in the FCGI
>> case to make it go away.
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