Achieving Recovery in Service Composition with Assurance Points and Integration Rules - (Short Paper)

This paper defines the concept of Assurance Points (APs) together with the use of integration rules to provide a flexible way of checking constraints and responding to execution errors in service composition. An AP is a combined logical and physical checkpoint, providing an execution milestone that stores critical data and interacts with integration rules to alter program flow and to invoke different forms of recovery depending on the execution status. During normal execution, APs invoke rules that check pre-conditions, post-conditions, and other application rules. When execution errors occur, APs are also used as rollback points. Integration rules can invoke backward recovery to specific APs using compensation as well as forward recovery through rechecking of preconditions before retry attempts or through execution of contingencies and alternative execution paths. APs together with integration rules provide an increased level of consistency checking as well as backward and forward recovery actions.