Operate CacheCore

Signals to watch first

• hit ratio
• invalidation volume
• average load duration
• warm request volume
• stale reads that are expected versus accidental

Useful surfaces

• GET /health
• GET /ready
• GET /metrics
• GET /v1/metrics
• POST /v1/invalidate
• POST /v1/warm

Good operational posture

• keep tags low-cardinality and stable
• protect the admin API behind network boundaries
• use Redis-backed adapters for multi-instance deployments
• treat stale-while-revalidate as a policy choice, not a blanket default

Failure modes worth rehearsing

• expired entries: should be observable as misses
• stale entries: should serve old data once and refresh in the background
• tag invalidation: should clear both entry state and tag index state
• cold start pressure: should show up in load duration metrics