{
  "status": "shipping",
  "advantages": [],
  "limitations": [],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-22",
  "slug": "eventual-consistency",
  "term": "Eventual consistency",
  "aliases": [
    "Eventually consistent replication"
  ],
  "definition": "Eventual consistency requires replicas to converge after updates cease, assuming updates can propagate and conflicts are resolved.",
  "note": "The guarantee alone sets no fixed convergence deadline and does not imply read-your-writes or monotonic reads; these need additional contracts. Permanent communication failure prevents the propagation assumption from holding. [vogels-eventual]\n\nConcurrent writes need a resolution policy, not necessarily a last-writer-wins timestamp. The 2007 key-value-store design can return divergent versions for application-assisted reconciliation. [dynamo-paper]",
  "related": [
    "craq",
    "linearizability",
    "session-guarantees",
    "asynchronous-replication",
    "anti-entropy-repair"
  ],
  "citations": [
    {
      "id": "vogels-eventual",
      "title": "Werner Vogels: Eventually Consistent - Revisited, 23 December 2008",
      "url": "https://www.allthingsdistributed.com/2008/12/eventually_consistent.html",
      "accessed": "2026-10-22"
    },
    {
      "id": "dynamo-paper",
      "title": "Giuseppe DeCandia et al.: Dynamo: Amazon's Highly Available Key-value Store, SOSP 2007, section 4.4",
      "url": "https://www.allthingsdistributed.com/files/amazon-dynamo-sosp2007.pdf",
      "accessed": "2026-10-22"
    },
    {
      "id": "hesela-replication",
      "title": "Hesela: Replication acknowledgements: received, durable, applied",
      "url": "https://hesela.com/analyses/replication-acknowledgements-durability-lag/#eventual-consistency",
      "accessed": "2026-10-22"
    }
  ],
  "provenance": [
    "Dynamo (SOSP 2007) is historical system evidence, not a claim about current DynamoDB APIs. [dynamo-paper]"
  ]
}