Towards Efficient Abstractions for Concurrent Consensus

Abstract

Abstract. Consensus is an often occurring problem in concurrent and distributed programming. We present a programming language with simple semantics and build-in support for consensus in the form of communicating transactions. We motivate the need for such a construct with a characteristic example of generalized consensus which can be naturally encoded in our language. We then focus on the challenges in achieving an implementation that can efficiently run such programs. We setup an architecture to evaluate different implementation alternatives and use it to experimentally evaluate runtime heuristics. This is the basis for a research project on realistic programming language support for consensus.

Bisimulations for Communicating Transactions

“…Our bisimulations provide an e↵ective verification technique for the aforementioned contextual equivalence which can be applied to related programming languages where uncommitable actions have no e↵ect [5,7,11,16]. They can also serve as a verification technique for other forms of contextual equivalences, such as may-and must-testing equivalences [3,4].…”

“…Note that this is a communication-driven embedding, which reduces the nondeterminism of embedding of previous work [3,4], making semantics more concrete [16]. Embedding leads to a uniform treatment of CCS processes and transactions, and a simple reduction semantics.…”

“…For example, it can be used to simplify the programming of complex concurrent consensus scenarios, avoiding the use of locks and explicit error handling [16]. Variants of such constructs have been proposed as extensions to programming languages [5,7,11,16] and process calculi [2,1,3].…”

“…For example, it can be used to simplify the programming of complex concurrent consensus scenarios, avoiding the use of locks and explicit error handling [16]. Variants of such constructs have been proposed as extensions to programming languages [5,7,11,16] and process calculi [2,1,3]. However, before they can be adopted in mainstream programming, significant research is needed in e cient implementation strategies [6,11,16], programming paradigms [1,7], and viable verification techniques [8].…”

Distinguishing between communicating transactions

“…Transactional constructs without the isolation principle have been proposed as useful building blocks of distributed systems (e.g., [10,11,17,23,3,6]). Communicating transactions is such a construct, equipped with a rich theory providing techniques for proving behavioural equivalence of transactional systems [8,9,16].…”