Azure Event Grid Namespace (Preview) as an Event Grid source

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This article provides the properties and schema for Azure Event Grid namespace events. For an introduction to event schemas, see Azure Event Grid event schema.

Available event types

Azure Event Grid namespace (Preview) emits the following event types:

Event type Description
Microsoft.EventGrid.MQTTClientSessionConnected Published when an MQTT client’s session is connected to Event Grid.
Microsoft.EventGrid.MQTTClientSessionDisconnected Published when an MQTT client’s session is disconnected from Event Grid.
Microsoft.EventGrid.MQTTClientCreatedOrUpdated Published when an MQTT client is created or updated in the Event Grid Namespace.
Microsoft.EventGrid.MQTTClientDeleted Published when an MQTT client is deleted from the Event Grid Namespace.

Example event

This sample event shows the schema of an event raised when an MQTT client's session is connected to an Event Grid:

[{
  "specversion": "1.0",
  "id": "5249c38a-a048-46dd-8f60-df34fcdab06c",
  "time": "2023-07-29T01:23:49.6454046Z",
  "type": "Microsoft.EventGrid.MQTTClientSessionConnected",
  "source": "/subscriptions/aaaa0a0a-bb1b-cc2c-dd3d-eeeeee4e4e4e/resourceGroups/myrg/providers/Microsoft.EventGrid/namespaces/myns",
  "subject": "clients/client1/sessions/session1",
  "data": {
    "namespaceName": "myns",
    "clientAuthenticationName": "client1",
    "clientSessionName": "session1",
    "sequenceNumber": 1
  }
}]

This sample event shows the schema of an event raised when an MQTT client’s session is disconnected to Event Grid:

[{
  "specversion": "1.0",
  "id": "e30e5174-787d-4e19-8812-580148bfcf7b",
  "time": "2023-07-29T01:27:40.2446871Z",
  "type": "Microsoft.EventGrid.MQTTClientSessionDisconnected",
  "source": "/subscriptions/aaaa0a0a-bb1b-cc2c-dd3d-eeeeee4e4e4e/resourceGroups/myrg/providers/Microsoft.EventGrid/namespaces/myns",
  "subject": "clients/client1/sessions/session1",
  "data": {
    "namespaceName": "myns",
    "clientAuthenticationName": "client1",
    "clientSessionName": "session1",
    "sequenceNumber": 1,
    "disconnectionReason": "ClientInitiatedDisconnect"
  }
}]

This sample event shows the schema of an event raised when an MQTT client is created or updated in the Event Grid Namespace:

[{
  "specversion": "1.0",
  "id": "383d1562-c95f-4095-936c-688e72c6b2bb",
  "time": "2023-07-29T01:14:35.8928724Z",
  "type": "Microsoft.EventGrid.MQTTClientCreatedOrUpdated",
  "source": "/subscriptions/aaaa0a0a-bb1b-cc2c-dd3d-eeeeee4e4e4e/resourceGroups/myrg/providers/Microsoft.EventGrid/namespaces/myns",
  "subject": "clients/client1",
  "data": {
    "createdOn": "2023-07-29T01:14:34.2048108Z",
    "updatedOn": "2023-07-29T01:14:34.2048108Z",
    "namespaceName": "myns",
    "clientName": "client1",
    "clientAuthenticationName": "client1",
    "state": "Enabled",
    "attributes": {
      "attribute1": "value1"
    }
  }
}]

This sample event shows the schema of an event raised when an MQTT client is deleted from the Event Grid Namespace:

[{
  "specversion": "1.0",
  "id": "2a93aaf9-66c2-4f8e-9ba3-8d899c10bf17",
  "time": "2023-07-29T01:30:52.5620566Z",
  "type": "Microsoft.EventGrid.MQTTClientDeleted",
  "source": "/subscriptions/aaaa0a0a-bb1b-cc2c-dd3d-eeeeee4e4e4e/resourceGroups/myrg/providers/Microsoft.EventGrid/namespaces/myns",
  "subject": "clients/client1",
  "data": {
    "namespaceName": "myns",
    "clientName": "client1",
    "clientAuthenticationName": "client1"
  }
}]

Event properties

All events contain the same top-level data:

Property Type Description
id string Unique identifier for the event.
source string Full resource path to the event source. This field isn't writeable. Event Grid provides this value.
subject string Publisher-defined path to the event subject.
type string One of the registered event types for this event source.
time string The time the event is generated based on the provider's UTC time.
data object Event Grid namespace event data.
specversion string CloudEvents schema specification version.

The data object contains the following properties:

Property Type Description
namespaceName string Name of the Event Grid namespace where the MQTT client was connected or disconnected.
clientAuthenticationName string Unique identifier for the MQTT client that the client presents to the service for authentication. This case-sensitive string can be up to 128 characters long, and supports UTF-8 characters.
clientSessionName string Unique identifier for the MQTT client's session. This case-sensitive string can be up to 128 characters long, and supports UTF-8 characters.
sequenceNumber long A number that helps indicate order of MQTT client session connected or disconnected events. Latest event will have a sequence number that is higher than the previous event.
disconnectionReason string Reason for the disconnection of the MQTT client's session. The value could be one of the values in the disconnection reasons table.
createdOn string The time the client resource is created based on the provider's UTC time.
updatedOn string The time the client resource is last updated based on the provider's UTC time. If the client resource was never updated, this value is identical to the value of the 'createdOn' property
clientName string The time the client resource is last updated based on the provider's UTC time. If the client resource was never updated, this value is identical to the value of the 'createdOn' property.
state string The configured state of the client. The value could be Enabled or Disabled.
attributes string The array of key-value pair attributes that are assigned to the client resource.

Disconnection reasons:

The following list details the different values for the disconnectionReason and their description:

Disconnection Reason Description
ClientAuthenticationError the client got disconnected for any authentication reasons (for example, certificate expired, client got disabled, or client configuration changed)
ClientAuthorizationError the client got disconnected for any authorization reasons (for example, because of a change in the configuration of topic spaces, permission bindings, or client groups)
ClientError the client sent a bad request or used one of the unsupported features that resulted in a connection termination by the service.
ClientInitiatedDisconnect the client initiates a graceful disconnect through a DISCONNECT packet for MQTT or a close frame for MQTT over WebSocket.
ConnectionLost the client-server connection is lost.
IpForbidden the client's IP address is blocked by IP filter or Private links configuration.
QuotaExceeded the client exceeded one or more of the throttling limits that resulted in a connection termination by the service.
ServerError the connection got terminated due to an unexpected server error
ServerInitiatedDisconnect the server initiates a graceful disconnect for any operational reason
SessionOverflow the client's queue for unacknowledged QoS1 messages reached its limit, which resulted in a connection termination by the server
SessionTakenOver the client reconnected with the same authentication name, which resulted in the termination of the previous connection.

Next steps