Hi Kangle,

Regarding to OpenMetrics and AutoDiscovery example, the DataDog agent pod (daemonSet) running in the cluster will be monitoring the applications based on the annotations config. As long as the applications exposing a "/metrics" endpoint, DataDog agent will scrape the metrics from the app and publish them.

About DogStatsD, some services or applications don't support OpenMetrics or can't expose a "/metrics" endpoint (like Airflow, cronjob, etc.), or you want to collect custom metrics (business metrics, etc.) which DataDog doesn't support, you can configure the application to emit the metrics to DogStatsD (UDP/Unix) socket.

Feel free to let me know if the answer still not clear.

Regards,

James