Trading Integrity for Availability by Means of Explicit Runtime Constraints

Data integrity is one of the dependability attributes in data-centric applications. However, applications exist, e.g., safety or mission critical systems, where availability is more important for dependability than strict data integrity. Consequently, in such systems availability can be increased by temporarily relaxing data integrity. Potential inconsistencies are accepted by constraint validation on replicated copies, which are potentially stale in the face of network partitions. Such consistency threats need to be bound and eventually resolved during reconciliation. The contribution of this paper is a solution approach to this trade-off between availability and integrity by means of explicit runtime-management of data integrity constraints and consistency threats as well as reconciliation support