1 Objective
2 Issues & Decisions
3 Event Schema
- 3.1 Cloud event Definition
4 Controlling Notification
- 4.1 API to controlling delta notification
- 4.2 Persisting notification subscription
  - 4.2.1 delta-notification.yaml
5 Implementation details of delta notification

Objective

As of current implementation in cps core, after the update operation, entire configuration is sent as Kafka Notification. we are proposing to send only changed configuration as delta report in notification. It will help to understand what configuration exactly changed for the anchor.

Issues & Decisions

#	Issue	Notes	Decision

#	Issue	Decision
1	Do we need to update existing update notification to send delta notification or delta notification along with existing notification.	29-Sep-2023: We decided to implement delta notification separately without changing the existing update notification.
2	Using Liquibase v. Yang Model for storing new metadata per anchor in CPS Core	29-Sep-2023: We decided to use yang model to persisting delta notification subscription. No DB change is required. notification subscription information will be stored in Fragment table.
3	generic text field OK for future refinement, maybe consider json?	29-Sep-2023: subscription information will be persisted in JSON format

Event Schema

proposal for notification schema:

Cloud event Definition

	Element	Name	Parent	Type	Mandatory	Description	Format	(example) Value

	Element	Name	Parent	Type	Mandatory	Description	Format	(example) Value
1	Header	id		String	Yes	random id for cloud event header. UUID is suggested
2		source		String	Yes	source of information	fixed value	urn:cps:org.onap.cps
3		specversion		String	Yes	cloud event version spec	fixed value	1.0
4		type		String	Yes	type of event	fixed value	dataUpdateEvent
5		dataschema		String	Yes	data schema	fixed value	cps:org.onap.cps:data-updated-event-schema:1.0.0
6	Payload	data		Object	Yes	The actual data payload. Details will be provided below.
7		observedTimestamp	data	String	Yes	The timespamp of the event.	timestamp	2024-01-17 12:34:43
8		dataspaceName	data	String	Yes	The dataspace name where data is changed.		dataspace01
9		schemaSetName	data	String	No	The schemaset name for which data is changed.		bookstore
10		anchorName	data	String	Yes	The anchor name for which data is changed.		anchor01
11		operation	data	String	Yes	The operation performed on data.	CREATE UPDATE DELETE
12		xpath	data	String	Yes	The XPath which is changed		/bookstore

Controlling Notification

It is important to control the notifications for better performance. Notifications in cps-core will be controlled at Anchor level. By default notifications will be disabled for all anchors. notification can be enabled/disabled for an anchor or all anchors of a dataspace using below REST API.

API to controlling delta notification

Delta notification can be enabled/disabled by an additional admin API for list of anchors in a dataspace or all anchors in a dataspace.

API : PUT https://IP:PORT/cps/api/v2/dataspace/<dataspace-name>/deltanotification/<subscribe or unsubscribe>

Request Body :

["anchor01", "anchor02"]

Note: if no anchors list provided in request body than notification will be enabled/disabled for all the anchors for given dataspace.

Persisting notification subscription

Add schema for notification subscription and add subscription information in to Fragment table when delta notification is subscribed. delete the fragment when delta notification is unsubscribed.

below actions will be performed when delta notification will be subscribed for the dataspace.

schema set will be added to the dataspace when notification is subscribed.
An Anchor will be added to dataspace for notification subscription.
Subscription data will be added into fragment as per schema set.

schema yaml file to be used as below.

delta-notification.yaml

module notifications {
    yang-version 1.1;
    namespace "org:onap:ccsdk:sample";

    prefix delta-notification;

    revision "2024-01-10" {
        description
        "Sample Model";
    }
	container deltanotification {

        leaf notification-subscription {
            type string;
        }
	}
}

Implementation details of delta notification

For data nodes update operation, generate delta report by comparing previous and current configuration after successful update.
Process data update delta event and send notification as described in event schema above.

ONAP Wiki

Investigate Delta event notification after configuration update