[OpenLayers-Users] Performance question, or any tricks to consolidate WMS requests?

[Lance Dyas]

Cicconetti, Bob wrote:
>
> I have a prototype openlayers installation using data from a single 
> WMS server/map.  The performance with one or two layers is excellent, 
> but once you get to three or four it takes a while to finish grabbing 
> the off-screen tiles of the underlayers before grabbing the on-screen 
> tiles of the overlays.  (The maps consist of 3-5 base layers, and 6-8 
> overlays, most vector, but one bitonal raster parcel boundary layer.)
>
>  
>
> Is there a simple way to get Mapserver to do the compositing, short of 
> a bunch of combination/permutation layers that I would turn on and off 
> on demand?
>
WMS protocol allows combining layers at the server so yes...

> Perhaps extend LayerSwitcher to turn on and off WMS layers?
>
it could be done  essentially the combined layer names are comma 
separated list of names
Layer Switcher could be made to recognize the multiples and show them as 
individual layers
but still request them as composite.