Baquero, CarlosAlmeida, Paulo SérgioCunha, AlcinoFerreira, Carla2020-02-202020-02-202017-100252-9742PURE: 11630198PURE UUID: 934eff81-68d9-411a-aca8-86730ae5926aWOS: 000424478900004ORCID: /0000-0003-3680-7634/work/63724818http://hdl.handle.net/10362/93093project TEC4Growth (NORTE-01-0145-FEDER-000020).Keeping replicated data strongly consistent is convenient when communication is fast and available. In internet-scale distributed systems the reality of high communication latencies and likelihood of partitions, leads developers to adopt more relaxed consistency models, such as eventual consistency. Conflict-free Replicated Data Types, bring structure to the design of eventually consistent data management solutions, by precisely describing the behaviour under concurrent updates and guarantying a path to reconciliation. This paper offers a survey of the mathematical structures that support state based multi-master replication with reconciliation, and shows how state structures and state transformations can be composed to provide data types that are now used in practice in many geo-replicated systems.21210621engjournal articlehttp://eatcs.org/index.php/on-line-issues