# Delta state replicated data types

@article{Almeida2018DeltaSR,
title={Delta state replicated data types},
author={Paulo S{\'e}rgio Almeida and Ali Shoker and Carlos Baquero},
journal={ArXiv},
year={2018},
volume={abs/1603.01529}
}
• Published 4 March 2016
• Computer Science
• ArXiv
Abstract Conflict-free Replicated Data Types (CRDTs) are distributed data types that make eventual consistency of a distributed object possible and non ad-hoc. Specifically, state-based CRDTs ensure convergence through disseminating the entire state, that may be large, and merging it to other replicas. We introduce Delta State Conflict-Free Replicated Data Types ( δ -CRDT) that can achieve the best of both operation-based and state-based CRDTs: small messages with an incremental nature, as in…
52 Citations
Pure Operation-Based Replicated Data Types
• Computer Science
ArXiv
• 2017
This work introduces pure op-based CRDTs, that can only send operations to other replicas, drawing a clear distinction from state-based ones.
Partial Replication of Conflict-Free Replicated Data Types
• 2020
Conflict-free replicated data types (CRDT) are a class of data structures designed to simplify the operation of distributed systems that require data to be replicated in di↵erent nodes. CRDTs are
Verifying Strong Eventual Consistency in $\delta$-CRDTs
The central intuition is a pair of reductions between state-, δ-state, and op-based CRDTs that require less communication overhead from payload size, and tolerate relatively weak network environments, making them an ideal candidate for real-world use ofCRDTs.
Verifying Strong Eventual Consistency in δ-CRDTs
The central intuition is a pair of reductions between state-, $\delta$-state, and op-based CRDTs, formalized in the Isabelle interactive theorem prover and shown to show that state-basedCRDTs achieve SEC.
Log-Structured Conflict-Free Replicated Data Types
• 2021
Conflict-Free Replicated Data Types (CRDTs) are highly available data types conforming to strong eventual consistency. CRDTs do not need synchronization for concurrent updates and can resolve
Efficient Synchronization of State-Based CRDTs
• Computer Science
2019 IEEE 35th International Conference on Data Engineering (ICDE)
• 2019
Two sources of inefficiency in current synchronization algorithms for delta-basedCRDTs are identified and the concept of join decomposition is brought to state-based CRDTs to obtain optimal deltas and efficiency of synchronization algorithms are improved.
A Generic Undo Support for State-Based CRDTs
• Computer Science
OPODIS
• 2019
This paper works out an abstraction that captures the semantics of concurrent undo and redo operations through equivalence classes and device a mechanism to augment existing CRDTs, providing an “out of the box” support for undo without the involvement of the CRDT designers.
Conflict-Free Replicated Data Types in Dynamic Environments
The experimental results show that in volatile scenarios of disconnection, mobile users in collaborative activity maintain consistency among themselves and when compared to other available CRDT models, the P/S-CRDTs model is able to decouple the required knowledge of whom the updates must be disseminated to, while ensuring appropriate network traffic values.
A Conflict-Free Replicated JSON Datatype
• Computer Science
IEEE Transactions on Parallel and Distributed Systems
• 2017
This paper presents an algorithm and formal semantics for a JSON data structure that automatically resolves concurrent modifications such that no updates are lost, and such that all replicas converge towards the same state (a conflict-free replicated datatype or CRDT).
Conflict-Free Replicated Data Types CRDTs
• Computer Science
Encyclopedia of Big Data Technologies
• 2019
A conflict-free replicated data type (CRDT) is an abstract data type designed to be replicated at multiple processes and exhibiting the following properties: any replica can be modified without coordinating with another replicas.

## References

SHOWING 1-10 OF 53 REFERENCES
Efficient State-Based CRDTs by Delta-Mutation
• Computer Science
NETYS
• 2015
This work introduces Delta State Conflict-Free Replicated Datatypes ($$\delta$$-CRDT) that can achieve the best of both worlds: small messages with an incremental nature, disseminated over unreliable communication channels.
Conflict-Free Replicated Data Types
• Computer Science
SSS
• 2011
This paper formalises two popular approaches (state- and operation-based) and their relevant sufficient conditions and studies a number of useful CRDTs, such as sets with clean semantics, supporting both add and remove operations, and considers in depth the more complex Graph data type.
A Scalable Conflict-Free Replicated Set Data Type
• Computer Science
2013 IEEE 33rd International Conference on Distributed Computing Systems
• 2013
This work improves the original CRDT specification by introducing an efficient algorithm for sending deltas of updates between replicas and by partitioning a set replica into disjunctive subsets, and adds support for limited-lifetime elements to enable simple garbage collection strategies to address the problem of unbounded database growth.
Riak DT map: a composable, convergent replicated dictionary
• Computer Science
PaPEC '14
• 2014
The design of a new convergent (state-based) replicated data-type, the Map, as implemented by the Riak DT library and the RiAK data store is discussed, which allows greater flexibility to application developers working with semi-structured data, while removing the need for the developer to design custom conflict-resolution routines for each class of application data.
A comprehensive study of Convergent and Commutative Replicated Data Types
• Computer Science
• 2011
This paper formalises asynchronous object replication, either state based or operation based, and provides a sufficient condition appropriate for each case, and describes several useful CRDTs, including container data types supporting bothadd and remove operations with clean semantics, and more complex types such as graphs, montonic DAGs, and sequences.
Managing update conflicts in Bayou, a weakly connected replicated storage system
• Computer Science
SOSP '95
• 1995
The motivation for and design of these mechanisms for conflict detection and per -write conflict resolution based on client-provid ed procedures are presented and the experiences gained with an initial implementation of the system are described.
An optimized conflict-free replicated set
A reasoning abstraction, \emph{permutation equivalence}, is presented that systematizes the characterization of the expected concurrency semantics of concurrent types and presents one of the existing conflict-free replicated data types, Observed-Remove Set.
Replicated data types: specification, verification, optimality
• Computer Science
POPL 2014
• 2014
This work proposes a framework for specifying replicated data types using relations over events and verifying their implementations using replication-aware simulations, and shows how to specify consistency of replicated stores with multiple objects axiomatically, in analogy to prior work on weak memory models.
Optimized OR-Sets without Ordering Constraints
• Computer Science
ICDCN
• 2014
This work formalizes a concurrent specification for OR-Sets without ordering constraints and proposes a generalized implementation of OR-sets without tombstones that provably satisfies strong eventual consistency, and introduces Interval Version Vectors to succinctly keep track of distributed time-stamps in systems that allow out-of-order delivery of messages.
Scalable and Accurate Causality Tracking for Eventually Consistent Stores
• Computer Science
DAIS
• 2014
A new logical clock mechanism and a logical clock framework are proposed that together support a traditional key-value store API, while capturing causality in an accurate and scalable way, avoiding false conflicts.