Edge Monitor
The Edge Monitor monitors the status of the Edge Agents running on its cluster. It raises alerts over Sparkplug if an Edge Agent does not appear to be running correctly. It is also responsible for ensuring an Edge Agent reloads its configuration when an updated version becomes available from the Config Store.
ACS Monitor Component
Overview
The edge monitors are driven by Kubernetes resources deployed from the Helm charts which deploy the Edge Agents. These SparkplugNode resources identify an Edge Agent or other Sparkplug Node which should be monitored by UUID. The monitor looks up the Sparkplug address of the Node in the Config Store and observes its output. If a Node does not publish any packets for several minutes, the monitor will send a rebirth request to check the Node is still active. If a response is not received the monitor will raise an alert over its own Sparkplug interface.
If the Node is expected to be an Edge Agent (as specified in the SparkplugNode resource) the monitor will additionally verify that the Edge Agent is running with the current version of its configuration. The Edge Agent fetches its configuration from the Config Store at startup; along with the configuration, the Config Store returns an HTTP Etag identifying this particular revision of the config entry. The Edge Agent publishes this information in its Node birth certificate.
The edge monitor watches for change-notify messages from the Config Store and when an Edge Agent configuration entry changes so that the Edge Agent is not using the most recent version, the monitor will send a CMD to the Edge Agent instructing it to reload its configuration. If the Edge Agent does not respond appropriately an alert is raised.
MQTT interface
The Monitor publishes as a Sparkplug Node, and should be configured to
use the Monitor Node address under its cluster's Sparkplug Group. The
monitor creates a Device under this Node for each Node it is monitoring.
These Devices publish DBIRTH and DDEATH when the set of SparkplugNode
resources on the cluster changes; the monitor devices do not go offline
when the Nodes they are monitoring do.
The Node publishes using the Monitor Node schema UUID. An edge monitor publishes Link metrics linking the monitor Node to the UUID of the cluster it is responsible for. The Devices also publish Links, to the UUIDs of the devices they are monitoring. They also publish alert metrics for the alerts they can raise.
Well-known UUIDs
These well-known UUIDs are part of the core framework and all MUST to be registered with the Configuration Store component under the appropriate classes.