OpenLayers and Geoserver. Using multiple Servers for tiles

Question

OpenLayers allows the wms layer to specify up to 4 servers to permit the browser to connect to a server multiple times

Has anyone had any experience in mapping those for servers to four Physical geoserver Instances. The Geoservers (v2.2.5) are sharing a common data directory, different cache directories for the Integrated GeoWebCache

Would it be reasonable to expect it to work ok? I believe the functionality is to point four different dns entries at the SAME Server, not Four DNS Entries to Four DIFERENT Servers sharing a common database.

The reason is we are trying to speed up tile delivery and the performance on the scenario of pointing 4 dns entries to one server is not what we would expect. We have done all the tuning on the Java side that we can find information on and want to see what impact this makes, if it is at all even possible. Platform is a public facing windows IIS7.7 and geoserver 2.2.5 on it own machine on a private network

We are also using a proxy that distributes the tile request to the Geoserver Instance on a private network. If we proceed, we could also use 4 proxy servers as the end points for the public Geoserver Request.

Comments and suggestions welcome.

Answer 1

Are you serving a tiled gridset to Openlayers? If so, then IMHO you'd be better off configuring standalone GeoWebCache (GWC) http://geowebcache.org and connecting that to your multiple Geoserver instances.

A single standalone GWC can deal with a huge amount of traffic, so I'd be surprised if that ended up being a bottleneck. The original idea of the multiple WMS URLs in openlayers is to avoid your browser restricting the number of concurrent requests to a single domain. If you're finding openlayers is struggling to load tiles quicker than they're able to be served by GS+GWC, then just create multiple domain names pointing to the same GWC and use those domains for the array of URLs.