[OpenLayers-Users] Strategy cluster and slow map behavior.

[Ivan Grcic]

I guess it shouldnt be too hard to do it with geoserver

cheers

2009/3/18 Heidt, Christopher M. <CHRISTOPHER.M.HEIDT at saic.com>

>  If your just pointing directly to a large kml file then you are right,
> but most systems have a handler that generates kml based on parameters.
>
>  ------------------------------
> *From:* users-bounces at openlayers.org [mailto:users-bounces at openlayers.org]
> *On Behalf Of *Tiemens, Gerben
> *Sent:* Wednesday, March 18, 2009 5:15 AM
> *To:* Ivan Grcic
> *Cc:* users at openlayers.org
> *Subject:* Re: [OpenLayers-Users] Strategy cluster and slow map behavior.
>
>  Thanks for your answer.
>
> I already searched in the way of WFS, but wanted it first to work with a
> simple KML. As searching in the mailinglist and other resources didn't give
> a solution, I will have to move to a WFS solution.
> BBOX strategy will not work on KML so that is nog the right way to go.
>
> Maybe there might be an idea to leave out the clusterfeatures that are out
> of view when using strategy cluster? Some sort of BBOX idea within the
> clustering, but then for not attaching all the available features in a
> KML to the layer, when features are out of view.(out of viewport bbox).
>
> Greets
>
> Gerben
>
>
>
>  ------------------------------
> *Van:* Ivan Grcic [mailto:igrcic at gmail.com]
> *Verzonden:* Tuesday, March 17, 2009 5:07 PM
> *Aan:* Tiemens, Gerben
> *CC:* users at openlayers.org
> *Onderwerp:* Re: [OpenLayers-Users] Strategy cluster and slow map
> behavior.
>
> Hi Tiemens,
>
> the problem is that the more you zoom in, more and more clusters are
> created. So at the first several levels, you only have several clusters,
> thats why it takes relativly small amount of time. The more you zoom in, it
> takes lots of time to calculate clusters.
>
> This is happening because you are working with all the features all the
> time, regardless of the bbox of the map (not good solution if you have more
> then 50-100 features)
>
> I suggest: using BBOX strategy that filters out the features depending on
> map extents, together with wfs protocol. Then it should work pretty fast.
>
> HINT: check ratio parametar and http://trac.openlayers.org/ticket/1830
>
> Cheers
>
>
> 2009/3/17 Tiemens, Gerben <Gerben.Tiemens at grontmij.nl>
>
>>
>> Hello OpenLayers List users,
>>
>>
>> I'm implementing the cluster strategy and im facing a problem. I have a
>> 500 features on the map from a KML file, with google layer as baselayer.
>> With clustering on the KML layer, the map acts really slow. When zooming
>> in, the map acts slower and slower. Every zoom step, the next zoomstep will
>> be slower.
>> When clustering is off, the map acts fast again, even it has more features
>> on it.
>> I turned of the special styling, but even that does not help in this case.
>> The map keeps acting slow with each zoom action.
>>
>>
>> My site is: http://www.getiem.nl/mineralmap/mineralmap.html
>> The javascript is on  http://www.getiem.nl/mineralmap/strahlen.js
>>
>>
>> Does anyone have an idea why clustering is slowing down on the zoomed in
>> map?
>> Is this a bug or issue to resolve?
>> Maybe you see a flaw in my code.
>>
>>
>>
>>    1. Steps to reproduce:
>>    2. Zoom in on the map.
>>    3. When zoomed in to lets say the Netherlands, its slowed down to
>>    seconds,
>>    4. when zooming further, each step takes longer.
>>
>>
>>
>> My first insights are:  all features are drawn in memory (also features
>> outside map), and thats why it is taking longer when zoomed in: it draws all
>> 500 features.  But thats not satisfying, since loading all features at once
>> and then zooming in is faster.
>>
>>
>> Greetings
>>
>> Gerben
>>
>>
>>
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>
>
> --
> Ivan Grcic
>
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-- 
Ivan Grcic
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