Exception Handling and Recovery of Semantic Web Services

In this paper we present an approach for specification of exception handling and recovery of semantic web services based on OWLS. We use standard fault handlers and compensation known for example from WS-BPEL to provide support for long running transactions. In addition to that, we introduce constraint violation handlers (CV-handlers) which allow a designer to define what situations are supposed to trigger an erroneous state and what are the appropriate recovery actions. Further, we introduce explicit recovery actions such as retry and replaceBy to recover from the failure and to restore a normal execution flow. By combining fault handlers, CV-handlers and standard event handlers it is possible to define ways of recovery for standard errors and for violations of constraints resulting for example from Service Level Agreements (SLAs).