CouchDB uses immutable MVCC revisions and the _rev parameter to prevent lost updates. Learn the safe update flow, how to retry after a 409, and why replication conflicts require explicit resolution.

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couchdb conflict-resolution mvcc

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Article0 replies3,540 followingPosted 07 May 2026, 22:44 UTC99.5K views4,758 votes

Implement Optimistic Concurrency in NHibernate 5.x with a Version Column

Map a version column, carry it across web requests, handle StaleObjectStateException with a bounded retry, and verify the UPDATE’s WHERE clause enforces the check.

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dotnet

nhibernate orm

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Article0 replies1,961 followingPosted 08 Feb 2026, 10:44 UTC110K views2,155 votes

Handling Optimistic Concurrency in FoundationDB: Retry Patterns and Limits

FoundationDB's optimistic concurrency control lets transactions run locally and validates at commit, requiring application-level retry logic. Learn the transaction cycle, a worked counter example, and how to monitor conflict rates.

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transaction-retry foundationdb distributed-kv

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Article1 reply1 comment2,168 followingPosted 25 Jun 2026, 03:44 UTC50.6K views3,316 votes

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Using Memcached CAS to Prevent Lost Updates in Read-Modify-Write Workloads

Memcached’s CAS token lets clients detect concurrent changes and safely retry read‑modify‑write updates without server‑side locking.

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memcached optimistic-concurrency cas

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Question1 answer1,203 followingPosted 01 Sept 2022, 22:19 UTC80K views2,601 votes

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FoundationDB Transaction Retry: Server-Side Idempotency Token Absence

Context FoundationDB's optimistic concurrency control returns retryable errors ( transaction_too_old , not_committed ) when read-write conflicts occur. The on_error callback automatically re-executes the entire transaction function, which re-applies any writes unless the application implements idempotency at the key level. Constraint Current patterns require

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transaction-retry foundationdb idempotency