Workflow Execution and Reliability

Workflow Execution and Reliability

Concurrency Control

30 of 69 in this book · 2 min read

Domain: Workflow, Execution & Reliability Engineering
Status: Implementation guidance / design checklist
Applicability: Depends on product architecture and risk

Concept

Concurrency Control is the capability concerned with concurrency control in the broader domain of durable automation with recoverable side effects. Its purpose is to make this concern explicit, testable, governable, and reusable across AI-powered workflows. Define the state machine, retry policy, and what side effects Concurrency Control may create.

Recommended Practices

  • Use durable queues, idempotency keys, explicit timeouts, reconciliation, and compensation where appropriate.
  • Define an owner, API/schema contract, failure response, and acceptance criteria for concurrency control.
  • Add automated positive, negative, boundary, and permission tests for concurrency control; review metrics in staging and production.

Example Use Cases

  • A long-running request survives worker restarts and avoids duplicating external tickets.
  • Apply concurrency control in a high-volume enterprise workflow while recording the user, project scope, input contract, and observable outcome.

Common Implementation Pitfalls

  • Blind retries, non-atomic state transitions, and claiming rollback for irreversible side effects.
  • No documented fallback, operational owner, or signal showing when concurrency control is failing.
  • Testing only happy paths while ignoring missing data, revoked access, malformed outputs, and partial outages.

Production Readiness Checklist

  • An accountable owner and technical contract for concurrency control are documented.
  • At least one successful and one failing end-to-end scenario is reproducible.
  • Access controls, retention, and audit requirements are verified where relevant.
  • Release monitoring includes a measurable success or failure signal for this capability.

Design Questions

  1. What concrete risk or business requirement requires Concurrency Control?
  2. What happens when it is unavailable, wrong, stale, or slow?
  3. How is its success evaluated against a trusted reference or observed outcome?
  4. Who can change its configuration, and how are changes released and rolled back?

Related Areas