Impl. Proposal CM Subscriptions : Delete ( Positive Scenarios )

References

CPS-1616 - Getting issue details... STATUS

CM Data Notification Subscription LCM (incl. merge)

Impl. Proposal CM Event Subscription LCM: Create

CPS-1776 - Getting issue details... STATUS

CPS-2251 - Getting issue details... STATUS

Out-of-scope

Working with wildcards and subscription update which will be taken care by a separate epic.
Subscription create ( done as part of a different story )
Merging of the ongoing subscriptions.

Assumptions

#	Issue	Notes	Decisions
1	Delete use case works for a valid ongoing subscription only.
2	Works only for the passthrough datastores.

Issues & Decisions

#	Issue	Notes	Decisions
1	Delete the subscription from the database?	24 Jun 2024 We plan to do it when we receive response from the DMI plugins and the underlying subscriptions from the devices are deleted.	23 Jul 2024 kieran mccarthy Agree
2	What do we need to send to the DMI Plugin so that they are able to decide that how to delete the ongoing subscription.	24 Jun 2024 We are sending cmHandle information and predicates information ( datastore , xpaths and cmHandle ) and private cmHandle properties.	23 Jul 2024 kieran mccarthy Agree
3	Who should be able to retry and make sure the subscriptions are deleted from the respective DMIs managing the devices.	kieran mccarthy The agenda for the next meeting. We can decide then. More on the "DELETING" stage ( if we want to have it )	kieran mccarthy As discussed on 17 Jul 2023 , The DME should be able to maintain Subscription State and make decision when to retry based on the response outcome we provide to it for create and/or delete use cases.
4	DME to NCMP Event to have targets and datastore-xpath-filter information for the subscription delete use case ?	17 Jul 2024 DME to only send the subscription id inorder to delete the request. NCMP will figure out the details corresponding to the provided subscription id and figure out what to request to DMI Plugin for deletion.	kieran mccarthy As per the discussion today 25 Jul 2023 we agreed to use targets , datastore-xpath-filters and datastores for the subscription delete use case. 17 Jul 2024 Revised approach is mentioned in the Notes section.
5	Do we send additional properties from NCMP to DMI	24 Jun 2024 We are sending additional/private properties as of now.	23 Jul 2024 kieran mccarthy Agree
6	Can the DMI Plugin REJECT the Cm Subscription Delete Request ?	kieran mccarthy Wanted to check if this is the VALID use case we have ?	23 Jul 2024 kieran mccarthy Yes it may be rejected or indicate partial failure. If one or more of the underlying data producers (node/ems) is disconnected for some reason then the request cannot be fulfilled. The client should be notified of the failure.

Algorithm for CM Subscription Delete

Capture Incoming subscriptionId from the client.
Query the existing subscriptions we are tracking using the subscriptionId we got from the Cm Subscription Delete request.
Populate the cmSubscriptionCache with the relevant details ( this will be later used to send the response and manage the subscription ) using the above query we did.
Now check if the details we have are ALL the last subscribers or not.
1. if all are NOT the last subscribers then we can right away delete it from the DB and send back the response to the client without sending any request to the DMI.
2. if we have mixed records then we need to make a call to the DMI for the "last lights out" to get Acceptance from DMI
if DMI accepts it , then whatever we have in the cache can be used to DELETE the rows from the DB ( similar to what we did for create )
Once the rows are deleted then we can send back the response to the client and clear up the cache ( for ACCEPTED/REJECTED )

Subscription Delete Sequence Diagram

Schema Definitions

DME to NCMP Cm Subscription Delete Request

	Name	Parent	Type	Example	Mandatory ?
1	id	header	String		Y
2	version	header	String	1.0	Y
3	source	header	String	DME	Y
4	type	header	String	subscriptionDeleteRequest	Y
5	dataschema	header	URI	org.onap.ncmp.cm.subscription:1.0.0	Y
6	data		Object		Y
7	subscriptionId	data	String	cm-subscription-001	Y
8	predicates	data	Object		N

Example

DME to NCMP Cm Subscription Delete Request

id : random-UUID
version : "1.0"
source : "DME"
type : "subscriptionDeleteRequest",
dataschema : org.onap.ncmp.cm.subscription:1.0.0  {
  "data": {
    "subscriptionId": "unique subscription id" // mandatory
}

NCMP to DMI-Plugin Subscription Request

	Name	Parent	Type	Example	Mandatory ?	Notes
1	id	header	String		Y
2	version	header	String	1.0	Y
3	source	header	String	NCMP	Y
4	type	header	String	subscriptionDeleteRequest	Y
5	dataschema	header	URI	org.onap.ncmp.dmi.cm.subscription:1.0.0	Y
6	correlationid	header	String	subscriptionId#dmiPluginName	Y	Concatenation of subscriptionId and dmi plugin name
7	data		Object		Y
8	cmHandles	data	Array		Y
9	cmhandleId	cmHandles	String		Y
10	privateProperties	cmHandles	Map		N
11	predicates	data	Array		N
12	targetFilter	predicates	Array of String		Y	list of cm handle ids
13	scopeFilter	predicates	Object		N
14	datastore	scopeFilter	String		Y	ncmp-datastore:passthrough-operational OR ncmp-datastore:passthrough-running
15	xpathFilter	scopeFilter	Array of String		Y

Example

NCMP to DMI-Plugin Subscription Request

id : random UUID
version : 1.0
source : "NCMP"
type : "subscriptionDeleteRequest"
dataschema : org.onap.ncmp.dmi.cm.subscription:1.0.0
correlationId ( concatenation of subscriptionId and dmi-plugin-name with a separator)
 
{
  "data": {
    "cmhandles" : [ // mandatory
    {
        "cmHandleId": "cmhandle1",
        "private-properties": {...}
    },
    {
        "cmHandleId": "cmhandle2",
        "private-properties": {...}
    },
    {
        "cmHandleId": "cmhandle3",
        "private-properties": {...}
    }
    ]
    "predicates": [
    {
        “targetFilter” :  [“cmHandle1”, “cmHandle2”, "cmhandle3"], // mandatory
        "scopeFilter" : {
           "datastore": “ncmp-datastore:passthrough-operational or ncmp-datastore:passthrough-running", // optional. default is passthrough-operational
           "xpath-filter": list of valid xpaths  // mandatory
      }
    },  
    {
        “targetFilter” :  [“cmHandle1”, “cmHandle2”, "cmhandle3"],
        "scopeFilter" : {
           "datastore": “ncmp-datastore:passthrough-operational or ncmp-datastore:passthrough-running", // optional. default is passthrough-operational
           "xpath-filter": list of valid xpaths  *
      }
    }
  ]
}

DMI-Plugin to NCMP Cm Subscription Delete Response

	Name	Parent	Type	Example	Mandatory ?	Notes
1	id	header	String		Y
2	version	header	String	1.0	Y
3	source	header	String	DME	Y
4	type	header	String	subscriptionDeleteResponse	Y
5	dataschema	header	URI	org.onap.ncmp.dmi.cm.subscription:1.0.0	Y
6	correlationid	header	String	subscriptionId#dmiPluginName	Y	Concatenation of subscriptionId and dmi plugin name
7	data		Object		Y
8	statusCode	data	String		Y	1 - Accept the subscription request 104 - Reject the subscription request
9	statusMessage	data	String		Y	ACCEPTED REJECTED

Example

DMI-Plugin to NCMP Cm Subscription Delete Response

id : random UUID
version : "1.0"
source : <dmi-plugin-name>
type : "subcriptionDeleteResponse"
dataschema : org.onap.ncmp.dmi.cm.subscription:1.0.0
correlationid : ( concatenation of subscriptionId and dmi-plugin-name with a separator)
{
"data" : {
   "statusCode": "1/104",  // mandatory
   "statusMessage" : "ACCEPTED/REJECTED" // mandatory
 }
}

NCMP to DME Cm Subscription Delete Response

	Name	Parent	Type	Example	Mandatory ?
1	id	header	String		Y
2	version	header	String	1.0	Y
3	source	header	String	DME	Y
4	type	header	String	subscriptionDeleteResponse	Y
5	dataschema	header	URI	org.onap.ncmp.cm.subscription:1.0.0	Y
6	correlationid	header	String	subscriptionId	Y
7	data		Object		Y
8	subscriptionId	data	String		Y
9	acceptedTargets	data	Array of String		N
10	rejectedTargets	data	Array of String		N
11	pendingTargets	data	Array of String		N

Example

NCMP to DME Cm Subscription Delete Response

id : random UUID
version : "1.0"
source : "NCMP"
type : "subcriptionDeleteResponse",
dataschema : org.onap.ncmp.cm.subscription:1.0.0,
correlationid : <subscriptionId> {
  "data": {
        "subscriptionId": "sample-subscription-id", // mandatory
        "acceptedTargets" : ["ch-1", ...], // optional
        "rejectedTargets" : ["ch-1", ...], // optional
        "pendingTargets" : ["ch-1", ...],  // optional
  }
}