CloudWatch / X-Ray
Metrics, logs, alarms and distributed tracing.
Problem it solves: You cannot fix what you cannot see.
Where it sits: Async side-path from every component.
When to use
- Always.
Failure modes
- High-cardinality labels explode cost.
Metrics to watch
- Ingest rate
- Alert noise
Configuration in Labs (illustrative defaults)
- Instances (count) = 1 — Identical copies behind this logical component. Capacity scales linearly in this model.
- Capacity per instance (req/s) = 50000 — Maximum requests one instance completes per second before it saturates.
Vendor examples (pattern only): AWS managed service. Simulated as a generic “Metrics / logs / traces”.