Overview
- Bug Type:
- Stale state/cache invalidation
- Category:
- Concurrency, Async & Events
Definition
Cached/replicated data is outdated due to missing or incorrect invalidation or revalidation.
How to fix Stale state/cache invalidation?
Define clear TTL/Revalidation rules; emit cache-bust events; use ETag/If-Match; align client and server caching semantics
Symptoms
Observable signs that may indicate Stale state/cache invalidation:
- Users see old data after update until cache expires.
- Inconsistent views across nodes/regions.
- Conditional requests not revalidating as expected.
Example Errors:
- ETag mismatch / 412 Precondition Failed
- No-cache directives ignored
- Replica lag warnings