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arXiv · 2210.12605

Keep CALM and CRDT On

Shadaj Laddad·Conor Power·Mae Milano·Alvin Cheung·Natacha Crooks·Joseph M. Hellerstein
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Abstract

Despite decades of research and practical experience, developers have few tools for programming reliable distributed applications without resorting to expensive coordination techniques. Conflict-free replicated datatypes (CRDTs) are a promising line of work that enable coordination-free replication and offer certain eventual consistency guarantees in a relatively simple object-oriented API. Yet CRDT guarantees extend only to data updates; observations of CRDT state are unconstrained and unsafe. We propose an agenda that embraces the simplicity of CRDTs, but provides richer, more uniform guarantees. We extend CRDTs with a query model that reasons about which queries are safe without coordination by applying monotonicity results from the CALM Theorem, and lay out a larger agenda for developing CRDT data stores that let developers safely and efficiently interact with replicated application state.

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Shadaj Laddad, Conor Power, Mae Milano, Alvin Cheung, Natacha Crooks, Joseph M. Hellerstein. 2022-10-23. Keep CALM and CRDT On. https://arxiv.org/abs/2210.12605

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