The SCEPTRE2 Communication Service In A Fault Tolerance Context

Abstract

SCEPTRE2 is a normative report on the basic mechanisms of the real-time executive kernels. No fault tolerance technique exists in its current version. So, in order to develop fault tolerant real time applications, redundancy management services must be provided. In this paper we present some aspects of a fault tolerance implementation in SCEPTRE2 and we focuse particularly on the communication problem, when redundancy exists. Our approach to fault tolerance is based upon the replication of capsules on distinct sites. The adopted replication strategy is the semi-active redundancy. The underlying communication system is synchronous, dependable and implements an atomic broadcastlmulticast. Communication services between capsules ensures that, on one hand, all the capsule replicas have the same inputs, which are used in the same order, and on the other hand sending messages are not duplicated.