A Practical Distributed Universal Construction with Unknown Participants

TL;DR

This paper introduces a client-delegated, obstruction-free universal construction for distributed shared memory that operates asynchronously without participant knowledge, demonstrated through a prototype on Cassandra and compared to Zookeeper.

Contribution

It presents a novel client-delegated universal construction using new abstractions, improving scalability and flexibility in distributed systems.

Findings

Prototype implementation on Cassandra shows practical viability.

Empirical comparison indicates performance benefits over Zookeeper.

Construction is obstruction-free and asynchronous, with no participant knowledge required.

Abstract

Modern distributed systems employ atomic read-modify-write primitives to coordinate concurrent operations. Such primitives are typically built on top of a central server, or rely on an agreement protocol. Both approaches provide a universal construction, that is, a general mechanism to construct atomic and responsive objects. These two techniques are however known to be inherently costly. As a consequence, they may result in bottlenecks in applications using them for coordination. In this paper, we investigate another direction to implement a universal construction. Our idea is to delegate the implementation of the universal construction to the clients, and solely implement a distributed shared atomic memory at the servers side. The construction we propose is obstruction-free. It can be implemented in a purely asynchronous manner, and it does not assume the knowledge of the participants. It is built on top of grafarius and racing objects, two novel shared abstractions that we introduce in detail. To assess the benefits of our approach, we present a prototype implementation on top of the Cassandra data store, and compare it empirically to the Zookeeper coordination service.