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Workflow Database Concurrency

Summary​

No row-version property, concurrency token, optimistic concurrency configuration or explicit locking exists.

Implemented protection​

Task commands require Pending status in a Running instance, which prevents sequential duplicate decisions. Unique constraints protect tenant/key, definition/version and event identifiers.

Race conditions​

Concurrent requests can load the same Pending task before either save completes. Without a concurrency token or lock, application guards alone do not establish a verified single-winner database guarantee.

Other boundaries​

Outbox event uniqueness can reject duplicate event identifiers. No command-level idempotency key or start-instance uniqueness exists.

Classification​

Sequential duplicate protection is implemented. Database concurrency control is Not implemented.

Requires Confirmation​

Expected contention, retry/error behavior and the chosen optimistic or pessimistic strategy require confirmation.

Source References​

  • microservices/src/workflow-service/Domain/Workflow/WorkflowInstance.cs
  • microservices/src/workflow-service/Application/Commands/WorkflowInstanceCommands.cs
  • microservices/src/workflow-service/Infrastructure/WorkflowDbContext.cs

See Also​

Keywords​

Workflow database, EF Core, Workflow schema.

Revision Information​

  • Status: Draft
  • Last reviewed: 2026-07-20
  • Next review: 2026-10-20