Minuet: Rethinking Concurrency Control in Storage Area Networks

Clustered applications in storage area networks (SANs), widely adopted in enterprise datacenters, have traditionally relied on distributed locking protocols to coordinate concurrent access to shared storage devices. The authors examine the semantics of traditional lock services for SAN environments and ask whether they are sufficient to guarantee data safety at the application level. They argue that a traditional lock service design that enforces strict mutual exclusion via a globally-consistent view of locking state is neither sufficient nor strictly necessary to ensure application-level correctness in the presence of asynchrony and failures. They also argue that in many cases, strongly-consistent locking imposes an additional and unnecessary constraint on application availability.