A Datalog Framework for Conflict-Free Replicated Data Types

2026-05-29

AI Summary

This work addresses the challenge of modeling and verifying the semantics of concurrent updates in distributed, local-first collaborative systems. It proposes a declarative framework based on Datalog that, for the first time, systematically encodes the semantics of Conflict-Free Replicated Data Types (CRDTs) and their compositions into executable logic programs. By explicitly representing operational contexts, the framework captures concurrent behaviors and enables compositional analysis. Integrated with property-driven testing, the approach is validated in a collaborative graph editing scenario, demonstrating correctness and exhibiting strong scalability with respect to both the number of operations and replicas.

Abstract

Distributed applications increasingly support local-first collaboration over shared data, allowing multiple users to perform updates concurrently without global coordination. Such collaboration requires careful design to capture the intended semantics of the concurrent interactions. We introduce a declarative framework for specifying and reasoning about the semantics of conflict-free replicated data types (CRDTs) and CRDT-based applications in Datalog. The framework models CRDT semantics as executable logic programs over operation contexts, making concurrency explicit and compositional, and thus amenable to automated analysis. As one application, we use property-based testing to compare implementations. To the best of our knowledge, this is the first work to systematically use Datalog as a foundation for prototyping and analyzing complex CRDTs and their compositions. We evaluate our methodology using a collaborative graph data editing case study and report experimentation results assessing correctness validation and scalability with an increasing number of operations and replicas.

Problem

• Conflict-Free Replicated Data Types
• Distributed Collaboration
• Concurrency Semantics
• Local-First Computing
• Declarative Specification

Innovation

• Datalog
• Conflict-Free Replicated Data Types
• Declarative Specification
• Concurrency Modeling
• Property-Based Testing