What software package runs autonomously and continuously on servers?

The Amazon CloudWatch agent is designed to run autonomously and continuously on servers to monitor system metrics and application logs. By deploying the CloudWatch agent on your Amazon EC2 instances or on-premises servers, you can collect a wide variety of data, including CPU utilization, disk I/O, memory usage, and log files.

This functionality is crucial for maintaining performance and identifying potential issues in real-time. The CloudWatch agent can be configured to send the collected metrics back to Amazon CloudWatch, where they can be visualized, tracked, and used to trigger alarms based on specified thresholds.

Options like Amazon S3, Amazon RDS, and AWS Lambda are fundamentally different. Amazon S3 is an object storage service that doesn't run autonomously as it's a storage solution rather than a monitoring tool. Amazon RDS is a managed relational database service that handles database management operations for you, but it is not designed to run continuously in the same context as the monitoring capabilities of the CloudWatch agent. AWS Lambda, while enabling serverless compute, runs functions in response to events and is not a dedicated service that continuously runs monitoring tasks like the CloudWatch agent. Therefore, the choice of the CloudWatch agent effectively signifies the correct understanding of ongoing server monitoring.