Dependability design for distributed real-time systems with broadcast communication

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Tezin Türü: Doktora

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Elektrik ve Elektronik Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2014

Öğrenci: YUSUF BORA KARTAL

Danışman: ŞENAN ECE SCHMİDT

Özet:

The operation of distributed systems relies on the timely exchange of message data via dependable communication networks. Previous works suggest hardware redundancy for potential faults in the underlying network infrastructure to achieve dependability. However, software faults and faults that cannot be resolved on the hardware level are not considered in the existing literature. This work proposes a new method for software fault-tolerant communication in distributed real-time systems with communication networks that support time-slotted operation and broadcast transmission. Our method implements a dependability plane to be integrated to the existing network stack. It processes dependability information that is piggybacked on application message and uses a time synchronized checkpointing/rollback recovery strategy. The proposed dependability plane is modeled in the framework of timed input/output automata (TIOA) to formally prove its correctness and determine tight bounds for fault-recovery times. Model checking tools are employed to verify the timing and dependability properties of real-time systems. To this end, we present an algorithmic approach for converting TIOA models to be used as input of a well known model checking software tool UPPAL. We apply our dependability plane design and integrate it to a previously developed real-time communications framework. We further verify the TIOA models of the overall protocol stack by employing our algorithmic conversion to UPPAAL.