Semantic interoperability

2 minute read

This section contains information about the semantic definitions and data sources available for subscription. It is divided into two main tabs:

Data sources

This section shows a list of all data sources registered in this Dataports instance (data sources are defined in https://github.com/DataPortsProject/dac-mongo-seed-models).

The list contains two actions:

Inspect data model

Show the contents of data model associated to the data source.

View agents using this data source

Shows all the running agents which are able to produce data according to the data model for this data source

Subscriptions

In this tab we can see active subscriptions to data sources and create new ones.

The inspect action shows the subscription object created by the Orion Context Broker. This view is useful to see the execution metrics for each individual subscription. For example:

{
  "id": "63f74a59f894fd770c6cf572",
  "description": "...",
  "status": "active",
  "subject": {
    "entities": [
      {
        "idPattern": "urn:ngsi-ld:...",
        "type": "TrackableEvent"
      }
    ],
    "condition": {
      "attrs": []
    }
  },
  "notification": {
    "timesSent": 633367,
    "lastNotification": "2023-05-12T11:19:20.000Z",
    "attrs": [],
    "onlyChangedAttrs": false,
    "attrsFormat": "normalized",
    "httpCustom": {
      "url": "..."

    },
    "lastFailure": "2023-05-12T11:00:21.000Z",
    "lastFailureReason": "Timeout was reached",
    "lastSuccess": "2023-05-12T11:19:20.000Z",
    "lastSuccessCode": 500,
    "covered": false
  }
}

The notification property contains information about how many times the notification has been triggered, when the notification last succeeded or failed and additional information.

Creating new subscription from the UI

The Create subscription provides an interface to create simple notifications based on an id pattern.

In this wizard you can provide:

• ID: a regex expression to match entities ids.
• type: the entity type
• Description: a human-like description of this subscription.
• Notification URL: the endpoint to which Orion will make a POST request each time the subscription triggers a notification.

If a more advanced subscription is needed, it will require calling the corresponding endpoint in the API. See Creating Subscriptions from the API for more information.