An OMNET++ model to asses node fault-tolerance mechanisms for FTT-Ethernet DESs

Abstract

Distributed embedded systems (DESs) that operate in dynamic environments require emerging flexibility and adaptivity communication requirements. When those DESs are deployed for critical applications, they must also employ appropriate fault-tolerance (FT) mechanisms to attain a high level of reliability. The FTT-Ethernet communication protocol supports the flexibility needed in dynamic environments, but does not provide adequate fault tolerance. In order to overcome this limitation the ongoing FT4FTT project proposes a communication architecture that includes fault-tolerance capabilities at different levels of DESs relying on FTT-Ethernet. In particular, it provides communication and execution mechanisms to tolerate node failures by means of active node replication with majority voting. This paper builds upon a previous OMNET++ model of an FTT-Ethernet-based DES in order to add, simulate and assess those mechanisms. Specifically, it models the communication mechanisms envisaged to enforce replica determinism in the voting procedure, as well as to trigger and coordinate the tasks executed in the replicas.