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Core Metadata - Device System Events

System Events are events triggered by the add, update or delete of device metadata objects (Device, DeviceProfile, etc.). A System Event DTO is published to the EdgeX MessageBus each time a new object is added, an existing object is updated or when an existing objects is deleted.

System Event DTO

Edgex 3.0

System Event types deviceservice, deviceprofile and provisionwatcher are new in EdgeX 3.0

The System Event DTO has the following properties:

Property Description Value
Type Type of System Event device, deviceservice, deviceprofile, or provisionwatcher
Action System Event action add, update, or delete in this case
Source Source of the System Event core-metadata in this case
Owner Owner of the data in the System Event In this case it is the name of the device service that owns the device or core-metadata
Tags Key value map of additional data empty in this case
Details The data object that trigger the System Event the added, updated, or deleted Device/Device Profile/Device Service/Provision Watcher in this case
Timestamp Date and time of the System Event timestamp

Publish Topic

The System Event DTO for Device System Events is published to the topic specified by the MessageQueue.PublishTopicPrefix configuration setting above, which has a default of edgex/system-events, plus the following data items, which are added to allow receivers to filter by subscription.

  • source = core-metadata
  • type = device
  • action = add/update/delete
  • owner = [device service name which owns the device]
  • profile = [device profile name associated with the device]

Example Device System Event publish topics