A protocol for machine-readable cache policies in OGC web services: Application to the EuroGeoSource information system

An efficient access to the contents provided through OGC web services, widely used in environmental information systems, is usually achieved by means of caching strategies. Service-owners may be interested in expressing the conditions required to allow for this. If these conditions are expressed in a machine-readable way, automatic harvesters can be programmed to follow them. This paper proposes a protocol to specify and follow cache policies for OGC web services expressed in a machine-readable language. A preliminary implementation of this protocol has been tested in the EuroGeoSource project, where a number of Web Feature Services providing mineral deposits and energy resources are periodically cached to improve the efficiency and availability of several applications. The protocol addresses a nowadays common case, and can possibly be extended to allow for more detailed policies. Further work will help to determine how it could be integrated into a full Digital Rights Management system.