Semantic Caching for Web Services

We present a semantic caching scheme suitable for caching responses from Web services on the SOAP protocol level. Existing semantic caching schemes for database systems or Web sources cannot be applied directly because there is no semantic knowledge available about the requests to and responses from Web services. Web services are typically described using WSDL (Web Service Description Language) documents. For semantic caching we developed an XML-based declarative language to annotate WSDL documents with information about the caching-relevant semantics of requests and responses. Using this information, our semantic cache answers requests based on the responses of similar previously executed requests. Performance experiments—based on the scenarios of TPC-W and TPC-W Version 2—conducted using our prototype implementation demonstrate the effectiveness of the proposed semantic caching scheme.