‹Programming› 2022
Mon 11 - Thu 14 April 2022
Thu 24 Mar 2022 14:00 - 14:30 at Auditorium Nobre - Concurrency & Synchronization Chair(s): Ademar Aguiar

Concurrent objects with asynchronous messaging are an increasingly popular way to structure highly available, high performance, large-scale software systems. To ensure data-consistency and support synchronization between objects such systems often use distributed transactions with Two-Phase Locking (2PL) for concurrency control and Two-Phase commit (2PC) as atomic commitment protocol. Inquiry In highly available, high-throughput systems, such as large banking infrastructure, however, 2PL becomes a bottleneck when objects are highly contended, when an object is queuing a lot of messages because of locking.

In this paper we introduce Path-Sensitive Atomic Commit (PSAC) to address this situation. We start from message handlers (or methods), which are decorated with pre- and post-conditions, describing their guards and effect.

This allows the PSAC lock mechanism to check whether the effect of two incoming messages at the same time are independent, and to avoid locking if this is the case. As a result, more messages are directly accepted or rejected, and higher overall throughput is obtained.

We have implemented PSAC for a state machine-based DSL called Rebel, on top of a runtime based on the Akka actor framework. Our performance evaluation shows that PSAC exhibits the same scalability and latency characteristics as standard 2PL/2PC, and obtains up to 1.8 times median higher throughput in congested scenarios.

We believe PSAC is a step towards enabling organizations to build scalable distributed applications, even if their consistency requirements are not embarrassingly parallel.

Thu 24 Mar

Displayed time zone: Lisbon change

13:30 - 15:00
Concurrency & SynchronizationResearch Papers at Auditorium Nobre
Chair(s): Ademar Aguiar FEUP, Universidade do Porto
13:30
30m
Talk
Capturing High-level Nondeterminism in Concurrent Programs for Practical Concurrency Model Agnostic Record & ReplayVol. 5
Research Papers
Dominik Aumayr Johannes Kepler University Linz, Austria, Stefan Marr University of Kent, Sophie Kaleba University of Kent, Elisa Gonzalez Boix Vrije Universiteit Brussel, Belgium, Hanspeter Mössenböck JKU Linz
Link to publication DOI
14:00
30m
Talk
Path-Sensitive Atomic Commit: Local Coordination Avoidance for Distributed TransactionsVol. 5
Research Papers
Tim Soethout ING Bank; CWI, Tijs van der Storm CWI; University of Groningen, Jurgen Vinju CWI; Eindhoven University of Technology
Link to publication DOI
14:30
30m
Research paper
An Optimised Flow for Futures: From Theory to PracticeVol. 6
Research Papers
Link to publication