Overview
- Bug Type:
- Duplicate request
- Category:
- Concurrency, Async & Events
Definition
The same operation executes multiple times (retries/double-submits) and produces unintended duplicate side-effects.
How to fix Duplicate request?
Make operations idempotent; use idempotency keys; de-bounce UI; guard with uniqueness checks/server deduplication
Symptoms
Observable signs that may indicate Duplicate request:
- Double charges/duplicate records created by retries or resubmits.
- Idempotent endpoints behave inconsistently across retries.
- Network errors followed by duplicated side effects.
Example Errors:
- Order already processed
- Idempotency key conflict
- 409 Conflict on repeated POST