Which of the following best describes the function of the port 8125?

Port 8125 is primarily used for the submission of custom metrics via DogStatsD, which is a metrics aggregation service provided by Datadog. When applications are configured to send metrics, such as gauge values or counters, to Datadog, they often do so using DogStatsD, which utilizes port 8125 as its default listening port.

With DogStatsD, developers can send metrics in a more efficient and flexible manner, utilizing the datagram protocol (UDP), allowing for high throughput and minimal overhead. This capability is particularly useful for custom application metrics that may not be covered by default integrations. Consequently, port 8125 facilitates the aggregation and processing of these custom metrics before they are sent to the Datadog platform for monitoring and analysis.

The other functions listed, such as transmission of APM data or connection for receiving alerts, utilize different protocols and ports within Datadog’s infrastructure. For instance, APM (Application Performance Monitoring) data transmission typically uses a different approach and port, while alerts are handled through other mechanisms that do not involve port 8125 directly. Thus, option B accurately represents the specific function associated with port 8125 in the Datadog ecosystem.