Dear Gabriel - thanks for your very helpful reply.... > (a) How can we ensure that only the tiles that need to change in response > to > new/changed points do so?
- At the moment there are two ways of doing that. - 1) if the changes are performed through WFS (which I doubt), you don't - need to do anything. There's a WFS transaction listener that truncates - the tiles for the region affected by the transaction. - 2) Set up a GeoRSS poll task on the layer - <http://geowebcache.org/docs/current/configuration/layers/georss.html?highlight=georss> - This implies that you'll need to develop the Atom/GeoRSS feed that's - to be polled by GWC in order to get the latest changes. The structure - needs to be like the one in this example: - <https://github.com/GeoWebCache/geowebcache/blob/master/geowebcache/georss/src/test/resources/org/geowebcache/georss/test-data/mixedgeometries_feed.xml>. - The bad news is that it is not yet possible to configure a georss feed - for GeoServer embedded layers, so you'll need to create separate layer - definitions in <gs data dir>/gwc/geowebcache.xml We could use WFS to 'broadcast' the newly added and changed points I guess if that were possible. I think that we are going to need to provide a WFS service in any case because the user needs the ability to interrogate individual points to view metadata. So there should be some way of combining these two requirements. I imagine that I would need to write a WFS service (using Geoserver) that made new and changed points available somehow? Otherwise I think WFS would be too slow to drive the tiling for us. I had looked at the GeoRSS solution and had thought that it was the way to go - thanks for the github link - very useful guide. I think you're saying that I would not be able to use the default integration between geoserver and geowebcache that is configured as standard in the web-based configuration / server manager right? So I would need to configure the layers in both products and then match them up? > > (b) We have our own (high speed) point clustering solution to provide > point-clusters at most zoom levels - as we want to display just cluster > centres at most zoom-levels (apart from the most 'zoomed-in'). Is there a > better point-clustering alternative available in GeoServer? Could I use > my > own clusters for the different zoom levels? - I'm curious what is a point cluster? It's our solution to the point-generalization problem for different zoom levels. When the user zooms out we want them to see a marker icon that merely indicates 'there are N points in this region' (where N could be large) so that they know they have to zoom in further to find the actual points themselves . So the 'region' would be our pre-computed cluster boundary. I've seen plently of client-side solutions to this clustering / generalization problem, but they don't do a great job in many respects. I did look to see whether Geoserver somehow summarises clouds of points at low zoom levels, but could not find much. Maybe I didn't look in the right places though. - Check both GeoSever and GWC production recommendations: - <http://geowebcache.org/docs/current/production/index.html> - <http://docs.geoserver.org/stable/en/user/production/index.html> - And this publication contains a couple descriptions of real world - production scenarios: - <http://opengeo.org/publications/geoserver-production/> Thanks - great articles. -- View this message in context: http://osgeo-org.1803224.n2.nabble.com/Large-Volatile-Point-Dataset-WMS-and-WFS-tp6961594p6969119.html Sent from the GeoServer - User mailing list archive at Nabble.com. ------------------------------------------------------------------------------ RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 _______________________________________________ Geoserver-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geoserver-users
