You want to receive an email notification when monthly AWS usage is likely to exceed your expected amount. Which service is the most appropriate?

Explanation

AWS Budgets lets you configure email notifications based on a budget amount or forecasted overrun. For personal development, this is the basic safeguard against billing accidents.

Per-choice explanations

Practical Use

AWS Budgets lets you set thresholds for monthly, quarterly, or annual budgets, as well as budgets scoped by specific service, tag, or linked account. When actual or forecasted values exceed the threshold, notifications are sent via SNS or email. It supports several budget types (cost budget, usage budget, RI / Savings Plans coverage and utilization budgets) and is used as the basic budget management tool from personal development through large organizations. The first two action-enabled budgets are free, and additional budgets are billed at a small daily amount. A similar service is AWS Cost Explorer, but Cost Explorer is a dashboard for visualizing and analyzing past and forecasted cost trends and does not provide threshold-based alerts. Cost Anomaly Detection uses machine learning to detect unusual spending patterns, and combining it with Budgets allows early detection of unexpected spikes in service usage. For personal development, a basic pattern that prevents billing accidents is to set a small budget at the start of the month (for example, 1,000 yen) and send three-stage alerts at 80%, 100%, and 120% to email through SNS. On SAA-C03, requirements such as "notification when the budget is exceeded," "cost monitoring," and "email notification" point to AWS Budgets. CloudTrail (API operation auditing), EFS (shared file storage), and Route 53 Resolver (DNS name resolution) are all services for different purposes than cost management. The distinction with Cost Explorer, Cost Anomaly Detection, and Budgets Actions (which can automatically apply IAM policies or stop EC2 when a threshold is crossed) are also asked in higher-level exams.