In an asynchronous system, where processes can crash, perfect predicate detection for general predicates is difficult to achieve. A general predicate thereby is of the form a Ù b, where a and b refer to a normal process variable and to the operational state of that process, respectively. Indeed, the accuracy of predicate detection largely depends on the quality of failure detection. In this paper, we investigate the predicate detection semantics that are achievable for general predicates using either failure detector classes »ËP, ËP, or P . For this purpose, we introduce weaker variants of the predicate detection problem, which we call stabilizing and infinitely often accurate. We show that perfect predicate detection is impossible using the aforementioned failure detectors. Rather, ËP and P only allow stabilizing predicate detection. Consequently, we explore alternative approaches to perfect predicate detection: introducing a stronger failure detector, called ordered perfect, or restricting the general nature of predicates.
By: Felix C. Gaertner and Stefan Pleisch
Published in: RZ3361 in 2001
LIMITED DISTRIBUTION NOTICE:
This Research Report is available. This report has been submitted for publication outside of IBM and will probably be copyrighted if accepted for publication. It has been issued as a Research Report for early dissemination of its contents. In view of the transfer of copyright to the outside publisher, its distribution outside of IBM prior to publication should be limited to peer communications and specific requests. After outside publication, requests should be filled only by reprints or legally obtained copies of the article (e.g., payment of royalties). I have read and understand this notice and am a member of the scientific community outside or inside of IBM seeking a single copy only.
Questions about this service can be mailed to reports@us.ibm.com .