Which AWS service is used to monitor system performance and generate alarms when metrics exceed thresholds?

Amazon CloudWatch Metrics is the service specifically designed for monitoring system performance in AWS. It provides detailed visibility into resource utilization, application performance, and operational health by collecting metrics from various AWS services and user-defined custom metrics. Users can set thresholds for these metrics, and when those thresholds are exceeded, CloudWatch can automatically trigger alarms. This allows for proactive management of the AWS environment, enabling users to respond quickly to potential issues before they escalate.

In addition to monitoring metrics, Amazon CloudWatch can also provide insights into logs and events, further enhancing its capabilities in tracking system behavior and performance over time. The integration with various AWS services makes it an essential tool for maintaining operational efficiency.