Which source provides the metric for system memory used in Datadog?

The metric for system memory used in Datadog is primarily sourced from the Datadog Agent. The Datadog Agent is a lightweight process that runs on your hosts and is responsible for gathering critical system-level metrics, including memory usage, CPU load, disk activity, and other performance indicators.

When installed, the Datadog Agent collects metrics in real-time directly from the host machine, allowing you to monitor memory usage accurately and continuously. This direct collection method ensures that you have access to detailed and immediate memory metrics, which are essential for assessing the performance and health of your systems.

While other integrations might provide memory data, they typically aggregate or forward metrics from various cloud services or container environments. For example, AWS EC2 and CloudWatch integrations primarily focus on providing metrics from the AWS environment rather than the raw system-level metrics. Docker Integration focuses on container metrics specifically, which may not cover all aspects of system memory.

Thus, the Datadog Agent stands out as the primary and most comprehensive source for system memory metrics, making it the correct choice for this question.