Efficient renaming in sequence CRDTs

Abstract

To achieve high availability, large-scale distributed systems have to replicate data and to minimise coordination between nodes. Literature and industry increasingly adopt Conflictfree Replicated Data Types (CRDTs) to design such systems. CRDTs are data types which behave as traditional ones, e.g. the Set or the Sequence. However, unlike traditional data types, they are designed to natively support concurrent modifications. To this end, they embed in their specification a conflict-resolution mechanism.To resolve conflicts in a deterministic manner, CRDTs usually attach identifiers to elements stored in the data structure. Identifiers have to comply with several constraints, such as uniqueness or belonging to a dense order. These constraints may hinder the identifiers' size from being bounded. As the system progresses, identifiers tend to grow. This inflation deepens the overhead of the CRDT over time, leading to performance issues.To address this issue, we propose a new CRDT for Sequence which embeds a renaming mechanism. It enables nodes to reassign shorter identifiers to elements in an uncoordinated manner. Experimental results demonstrate that this mechanism decreases the overhead of the replicated data structure and eventually limits it. CCS Concepts• Theory of computation → Distributed algorithms; • Software and its engineering → Consistency; • Human-centered computing → Collaborative and social computing systems and tools; • Applied computing → Text editing;

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“…M. Nicolas et al (2020) devoted their study to the issue of effective renaming in the context of CRDTs for sequences and considered the issue of effective renaming of objects or text parts in CRDTs sequences based on the LSEQ algorithm. Renaming is an important operation that allows correctly handling insertion, deletion, and editing operations in such sequences.…”

Review of joint text editing algorithms Conflict-free Replicated Data Types (CRDT)

“…M. Nicolas et al (2020) devoted their study to the issue of effective renaming in the context of CRDTs for sequences and considered the issue of effective renaming of objects or text parts in CRDTs sequences based on the LSEQ algorithm. Renaming is an important operation that allows correctly handling insertion, deletion, and editing operations in such sequences.…”

Distributed access control for collaborative applications using CRDTs

“…Both policy operations and data operations need to rely on the result of a conflict resolution of the closest policy operation before them (parent policy). Multiple mechanisms can freely be chosen from, but we devise a reference -named epoch [6] -to that parent operation. The reference is sent along each operation.…”