The Dijkstra prize was awarded for one of Mani’s most well-known and influential papers: Distributed snapshots: determining global states of distributed systems. Though, as an aside, when I first came to Caltech, I knew Mani as the “C” in the BCMP theorem, which laid the basis for the study of queueing networks. Given that my thesis was primarily on queueing and scheduling, he was one of the godfathers… But, as influential as the BCMP theorem has been, I’d say it still falls second to the distributed snapshots paper, which has laid the foundation for the implementation of distributed algorithms and distributed systems.
As the citation for the award says: “The paper provides the first clear understanding of the definition of consistent global states in distributed systems. […] It has led to concepts such as vector time, isomorphism of executions, global predicate detection, and concurrent common knowledge. Applications of the results of observing the system in consistent states include the development of vector clocks, checkpointing and message logging protocols, correct protocols for detecting stable properties such as distributed deadlocks and termination, mutual exclusion algorithms, garbage collection protocols, cache coherency and file coherency protocols in distributed replicated file systems, distributed debugging protocols, protocols for total message order and causal message order in group communication systems, global virtual time algorithms used particularly in parallel and distributed simulations of discrete event systems, and collaborative sessions and editing protocols in wide area systems and on the grid.”