[Chameleon] performance concerns

Paul Spencer pspencer at dmsolutions.ca
Mon May 9 09:57:44 EDT 2005

Jacob is correct, IMHO ... laptops are notoriously bad for benchmarking 
performance esp when using it as both server and client.  I am a laptop 
user myself, and my laptop is pretty decent ... and I notice a 
substantial difference between running code locally and on a test server 
... even when it isn't chameleon ;)

That being said, my current plan is to move Chameleon towards the jsapi 
mode of operation as the default (and eventually only) mode of 
operation.  This is now being termed 'AJAX' by most developers on the 
various lists.

If all goes as planned ;) then Chameleon would become more of an 
application generator - you would design and test your application, then 
deploy a lighter-weight package to a production server that wouldn't 
require the full Chameleon runtime.  Just a notion right now, but I 
think it is the way to move in the future.



Jacob Delfos wrote:
> Hi Bart,
> I think you should be careful comparing with results from a laptop. We 
> have a laptop as well, which is significantly slower than a desktop. I 
> think it's mostly due to harddisk speed. Also, it matters a lot whether 
> the laptop is both the server and the client. Laptops make poor 
> servers..... I don't think it's so much the reading of the mapfile, 
> though....
> We also care a lot about performance. To be honest, I would not deploy a 
> chameleon site without javascript, because I fear clients would complain 
> about speed. For this reason, everything we deployed so far is version 1 
> based (where I got the javascript working flawlessly and quick). I don't 
> know whether javascript works without errors yet in version 2 (my CVS 
> has been down for a month, due to the company firewall being 
> misconfigured). I spent many days trying to figure out the extent bug in 
> version 2 (http://www.maptools.org/bugzilla/show_bug.cgi?id=989).
> I have been thinking of trying to modify a chameleon site, to experiment 
> with submitting to an iframe. All the iframe would need to do, is update 
> the scalebar, legend, and mapimage. I don't think I'd have to change 
> that much in the code.
> regards,
> Jacob
> -----Original Message-----
> From: chameleon-bounces at lists.maptools.org 
> <mailto:chameleon-bounces at lists.maptools.org> 
> [mailto:chameleon-bounces at lists.maptools.org] On Behalf Of Bart van den 
> Eijnden
> Sent: 8 May 2005 22:46
> To: chameleon at lists.maptools.org <mailto:chameleon at lists.maptools.org>
> Subject: [Chameleon] performance concerns
> Hi list,
> I am comparing an application built with Chameleon (based on the ROI 
> sample app) with an application built with Neapoljs (Tydac's product built 
> on PHP/Mapscript).
> Neapoljs is more client-side oriented, ie the only thing it updates most 
> of the time is the map image. So more like Chameleon's js api I guess.
> I notice a huge performance difference using a 30 Kb MAP file with local 
> datasets (shapefile and mapinfo) between Neapoljs and Chameleon, around a 
> factor 2 or 3 per zoom in. This worries me a bit, as the response times of 
> Chameleon are above 5 seconds on my local (quite fast) laptop.
> I can imagine storing (writing/reading) the whole 30 Kb MAP file as a 
> state in the session with every zoomin can be quite a bit of overkill, 
> seeing the only line that is gonna change is the extent most of the time. 
> Especially in applications where users can't influence the layers' 
> settings.
> Any thoughts on the performance? What could I try to speed it up? Are 
> there any plans for optimizing performance?
> Thanks in advance.
> Best regards,
> Bart
> -- 
> Using Opera's revolutionary e-mail client: http://www.opera.com/mail/
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|Paul Spencer                           pspencer at dmsolutions.ca   |
|Applications & Software Development                              |
|DM Solutions Group Inc                 http://www.dmsolutions.ca/|

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