The monthly AWS bill jumps by 300 percent overnight. What should you check first to find which service and usage type is responsible?
Show answer and explanation
Answer: C
Cost Explorer breaks spend down by service, usage type, account, and tag, and its daily granularity is enough to isolate the exact day the increase began. Grouping by usage type distinguishes, for example, data transfer from instance hours or from storage, which narrows the culprit to a specific resource or configuration change. Once the driver is known, you can decide whether to fix the configuration, delete the resource, or adjust the architecture.
Why the other options are wrong
- A. Shutting everything down destroys production services and is a panic response, not diagnosis.
- B. CPU dashboards show performance, and a cost spike often comes from storage, transfer, or an idle resource that is invisible there.
- D. Support can help with billing questions, but opening a case before identifying the driver wastes time you could spend on Cost Explorer.
Exam tip. Cost anomaly triage starts with Cost Explorer grouped by service and usage type.