GeoWebCache - A Great New WMS Tile Cacher
The good folks at the Open Planning Project have released a Java-based tile caching engine, GeoWebCache. From the web site:
GeoWebCache is a cache for WMS tiles implemented as an HttpServlet? in Java. It is run through a container like Jetty, Tomcat or JBoss. The response time is measured in milliseconds. It is based on JTilecache, a Google Summer of Code project by Chris Whitney.In a nut shell, a tile caching engine is a WMS server that points to other WMS servers. It caches the images from those other servers (either on the fly or seeded), so it's shelling out pre-rendered images rather than rendering map images on the fly, making it extremely fast.
I’ve been playing around with the latest release of GeoWebCache, and after some experimenting and testing, I have to say it’s fantastic. So fantastic I’m probably going to use it to replace Tilecache. And I like Tilecache.
Some of the feature highlights of GeoWebCache include:
- Support for multiple WMS backends per layer, queried in round robin fashion with automatic failover
- Microsoft Virtual Earth tiling support
- Google Maps tiling support
- Support for png (including 8 bit), jpeg, gif, and tiff output
- It's crazy fast
- Other niceties, like a cache expiration setting, so it can sorta maintain it's own cache currency
GeoWebCache is undergoing rapid development (current release is 0.7.2), but even at a pre-1.0 release it’s definitely worth a look. Future releases are slated to include integration with GeoServer.
*Caveat: I’m an idiot.