Request Deduplication
Request deduplication lets matching callers share one request that is already running. Each caller receives the same result.
Another example
The header, account, and comment areas ask for the same user at once. The browser sends one network request, not three.
Main parts
- 01Stable key
- 02Matching callers
- 03In-flight request
- 04Shared result
- 05Dedupe window
Use it when
Use one stable key when several places need the same resource at nearly the same time.
Do not use it when
Do not share one request when the user, permissions, or parameters differ. Treat writes separately unless they are safe to repeat.
Name used in code
stable key -> one in-flight promise -> shared result Before you ship
Check the runtime and version, integration limits, dependencies and licenses, and platform support. Verify security, failure, speed, monitoring, deploy, support owner, upgrade path, and rollback.
Outcome: Use or review Request Deduplication as a technical building block that the team can maintain. User context: The header, account, and comment areas ask for the same user at once. The browser sends one network request, not three. Technology or engineering concept: Request Deduplication. Why it fits: Use one stable key when several places need the same resource at nearly the same time. Do not use it when: Do not share one request when the user, permissions, or parameters differ. Treat writes separately unless they are safe to repeat. Engineering fit: Define where it runs and which version to use. Set its job, interfaces, data flow, dependencies, supported systems, security, and speed limits. Explain how it fits the current stack. Lifecycle safeguards: Check dependency health and licenses. Add monitoring and a fallback. Name the upgrade owner. Do not add a second tool for the same job without a measured benefit. Acceptance criteria: A small integration proves the needed behavior. Test compatibility, security, failure, and performance. Document deploy, upgrade, support, and rollback steps. Evidence and limits (evidence boundary): It is official for that source. Other platforms or teams may use the term in another way. Unknowns to confirm: Current stack, runtime and version rules, target systems, dependency owner, performance budget, support period, and migration limits.
Check this request
Review the current use of Request Deduplication. Definition: Request deduplication lets matching callers share one request that is already running. Each caller receives the same result. Release checks: Check the runtime and version, integration limits, dependencies and licenses, and platform support. Verify security, failure, speed, monitoring, deploy, support owner, upgrade path, and rollback. Before changing code, report the evidence you found, gaps, severity, and the smallest safe fix.