CPS-1034 Publish LCM Events on Cmhandle State Change(NcmpEventsCmHandleStateHandler)

CPS-1034: Publish lifecycle events for ADVISED , READY and LOCKED state transitionClosed

#	Issue	Notes/Jira	Decision

#	Issue	Notes/Jira	Decision
1	Agree on a solution	proceed with Solution#2 as it would be more scalable.

Implementation Proposal

Problem Statement :

To publish the NcmpEvent when there is a change in the cmHandleState ( state transition )

Scenarios to keep in mind

We have to introduce a detail field in the NcmpEvent payload which can contain the previous state and other details.
We have to publish an event on public properties update ( even though we dont have any state change ???? )

Potential Solutions

Use code triggers
Any other solution ? Common State Handler

Solution #1 : Code Triggers

Identify all the possible cm handle state transitions.

State Transition Event	previousState	targetState

State Transition Event	previousState	targetState
NOTHING_TO_ADVISED	NOTHING	ADVISED
ADVISED_TO_LOCKED	ADVISED	LOCKED
LOCKED_TO_ADVISED	LOCKED	ADVISED
ADVISED_TO_READY	ADVISED	READY
READY_TO_LOCKED	READY	LOCKED
LOCKED_TO_READY	LOCKED	READY
ADVISED_TO_DELETING	ADVISED	DELETING
READY_TO_DELETING	READY	DELETING
LOCKED_TO_DELETING	LOCKED	DELETING
DELETING_TO_DELETED	DELETING	DELETED

Create a cmHandleState handler which takes in the cmHandleState transition event
-- Responsible for identifying the state transition
-- Based on state transition call the relevant methods to create the NcmpEvent accordingly.
Identify the trigger points in the code where the actual state transitioning is happening and call the handler from there and provide the type of transition.

Overview

2. Solution #2

Responsibilities of the state handlers

Accept : cmHandleId and other common params.
Set the object to the required state.
Persist the new state.
Send the correct event about the state change.

Identify the input and output params.
I/P : examine the existing code , identify the commonalities and then propose.

Current State Transition:

Create Registration (NEW to ADVISED)
Module Sync Success ( ADVISED TO READY)
Fail (ADVISED TO LOCKED)
Retry ( LOCKED TO ADVISED )
Deleting ( ADVISED to DELETING , READY to DELETING, LOCKED to DELETING ) / separate us **
Deleted ( DELETING to DELETED ) separate us ** CPS-1120: Actions we need to perform when cmHandleState changes from * to DELETING and then DELETING to DELETEDClosed

At a high level the method signature should like below.

State Handler

    /**
     * Responsible for handling the state transition and publishing the lcm event if required.
     *
     * @param cmHandleId          cm handle id
     * @param yangModelCmHandle   cm handle represented as Yang Model
     * @param targetCmHandleState target cm handle state
     */
    void updateState(final String cmHandleId, final YangModelCmHandle yangModelCmHandle,
            final CmHandleState targetCmHandleState);

References :

CPS-799 Spike: Define states and state handling for CM handle

CPS-858 Define Notifications on CM Handle Add (Ready) & Delete