A Preemptive Deterministic Scheduling Algorithm for Multithreaded Replicas

Software-based active replication is expensive in terms of performance overhead. Multithreading can help improve performance; however, thread scheduling is a source of nondeterminism in replica behavior. This paper presents a Preemptive Deterministic Scheduling (PDS) algorithm for ensuring deterministic replica behavior while preserving concurrency. Threads are synchronized only on updates to the shared state. A replica execution is broken into a sequence of rounds, and in a round each thread can acquire up to two mutexes. When a new round fires, all threads’ mutex requests are known; thus, it is possible to form a deterministic scheduling of mutex acquisitions in the round. No inter-replica communication is required. The algorithm is formally specified, and the proposed formalism is used to prove its correctness. Failure behavior and performance of a PDS algorithm’s implementation are evaluated in a triplicated system and compared with two existing solutions: nonpreemptive dete...

• Type: Conference
• Year: 2003
• Where: DSN
• Authors: Claudio Basile, Zbigniew Kalbarczyk, Ravishankar K. Iyer
• Keywords: Computer Networks, Deterministic, Deterministic Scheduling, DSN 2003, Nonpreemptive Deterministic Schedulers