The metrics that measure system memory ("system.mem.used") comes from which source?

The metrics that measure system memory, such as "system.mem.used," are sourced from the Datadog Agent. The Datadog Agent is an application that collects events and metrics from your servers, including various system-level metrics like memory usage, CPU load, disk usage, and more. It runs on your hosts and gathers data that can then be sent to the Datadog platform for monitoring and analysis.

While integrations like AWS EC2 or Docker may capture specific metrics related to those environments, the base metrics regarding system memory are directly obtained from the Datadog Agent operating on the host machine. This makes the Agent the primary source for that type of system-level metric, enabling users to obtain a holistic view of their system's performance.