| name | shortname | status | editor |
|---|---|---|---|
Endpoint Metadata Events |
15/EME |
draft |
Andrew Kokhanovskyi <ak@kaaiot.io> |
Endpoint Metadata Events is a method for Kaa services to communicate metadata updates that occur to endpoints. This RFC reuses the Endpoint Lifecycle and Connectivity Events design documented in 9/ELCE, including the broadcast messaging style and the NATS subject format, and defines a new event group and event type for metadata events.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.
Originator MUST publish an endpoint metadata updated event on any changes to endpoint metadata.
The {event-group} is metadata.
The {event-type} is updated.
Originators MUST publish endpoint events to the following NATS subjects:
kaa.v1.events.{originator-service-instance-name}.endpoint.metadata.updated
where {originator-service-instance-name} is the name of the originator service instance.
It allows listeners to subscribe to events from a specific originator.
The NATS message payload is an Avro object with the following schema (0015-ep-metadata-updated.avsc):
{
"namespace":"org.kaaproject.ipc.event.gen.v1.endpoint.metadata",
"name":"MetadataUpdatedEvent",
"type":"record",
"doc":"Endpoint metadata updated event message",
"fields":[
{
"name":"correlationId",
"type":"string",
"doc":"Message ID primarily used to track message processing across services"
},
{
"name":"timestamp",
"type":"long",
"doc":"Message creation UNIX timestamp in milliseconds"
},
{
"name":"timeout",
"type":"long",
"default":0,
"doc":"Amount of milliseconds since the timestamp until the message expires. Value of 0 is reserved to indicate no expiration."
},
{
"name":"appVersionName",
"type":"string",
"doc":"Application version name the endpoint registered with"
},
{
"name":"endpointId",
"type":"string",
"doc":"Identifier of the endpoint that registered with the server"
},
{
"name":"removed",
"type":{
"type":"map",
"values":[
"null",
"string"
]
},
"doc":"Map of removed metadata key names to their former values. Value null is used to represent a null JSON."
},
{
"name":"added",
"type":{
"type":"map",
"values":[
"null",
"string"
]
},
"doc":"Map of added metadata key names to their values. Value null is used to represent a null JSON."
},
{
"name":"updated",
"type":{
"type":"map",
"values":{
"type":"record",
"namespace":"org.kaaproject.ipc.event.gen.v1.endpoint.metadata",
"name":"MetadataKeyUpdatedDto",
"fields":[
{
"name":"newValue",
"type":[
"null",
"string"
],
"doc":"New JSON value of the updated metadata key. Value null is used to represent a null JSON."
},
{
"name":"oldValue",
"type":[
"null",
"string"
],
"doc":"Former JSON value of the updated metadata key. Value null is used to represent a null JSON."
}
]
}
},
"doc":"Map of updated metadata key names to their old and new values"
},
{
"name":"originatorReplicaId",
"type":"string",
"doc":"Identifier of the service replica that generated the event"
}
]
}