This page contains details of planning and implementation of the migration functionality for instances in ACM-R. Rest interface users will be able to call a new endpoint in order to trigger the moving/migration of an instance from a source composition definition to a target composition definition. Calls to migrate the instance will take place on an instance-by-instance basis. The caller will have to supply the following parameters when making the call to migrate an instance.

• Source Composition Definition Id - The Id of the composition that the instance is currently based on.
• Target Composition Definition Id - The Id of the composition that the instance is to be migrated to.
• Instance Id - The Id of the instance that the caller wishes to migrate.

This operation will only be possible if:

• the source composition is primed
• the target composition is primed and contains the same element definitions present in the source composition
• the instance is deployed and based on the the source composition

Migration Sequence Diagram

Note: The functionality for the upload of a new composition definition already exists

@startuml
Title Migration Sequence
participant UserRest
participant ACM
participant DB
participant Participants

group Create New Composition type for Migration
UserRest -> ACM : Composition Definitions
ACM -> DB : Saved Definition
UserRest -> ACM : Prime Definition
ACM -> Participants: Prime Definition
end group

group Migration per Instance
/'Instance migration from source to target composition type. '/
UserRest -> ACM : Migrate Instance (InstanceId, sourceCompId, targetCompId)
note top
Instance migration from source to target 
composition type.
end note
alt "instance Id and Composition Ids exist"
  ACM -> UserRest : 202 Async Operation
  ACM -> DB : Definition Validation (v1 no new elements/structure)
  ACM -> DB : instance and AC Element will be set in a transitional state (UPGRADING)
  ACM -> Participants : Move from source to target composition
  Participants -> ACM : Move completed
  ACM -> DB : instance and AC Element will be set in a final state (DEPLOYED)\n and Comp Def IDs change for instance and AC Element
 else
  ACM -> UserRest : 400 Bad Reqest
end
end group
@enduml

End point, fail and rollback

Solution 1

Upgrade:

PUT /onap/policy/clamp/acm/v2/compositions/{{source_composition_id}}/instances/{{instance_id}}/upgrade
{
    compositionTarget = "{{target_composition_id}}"
}

After instance has been upgraded successfully, it could be retrieved using:

GET /onap/policy/clamp/acm/v2/compositions/{{target_composition_id}}/instances/{{instance_id}}

In success scenario, is it possible to revert the upgrade, using the same endpoint with composition id inverted.

If upgrade fail, the instance is still based to {{source_composition_id}} with deployOrder "UPGRADING" and stateChangeResult "FAILED".

In this scenario, is it possible to retry or rollback the upgrade, using the flag "rollback" set to true.

Retry:

PUT /onap/policy/clamp/acm/v2/compositions/{{source_composition_id}}/instances/{{instance_id}}/upgrade
{
    compositionTarget = "{{target_composition_id}}"
}

Rollback:

PUT /onap/policy/clamp/acm/v2/compositions/{{source_composition_id}}/instances/{{instance_id}}/upgrade
{
    rollback = "true",
    compositionTarget = "{{target_composition_id}}"
}

Solution 2

Upgrade:

PUT /onap/policy/clamp/acm/v2/compositions/{{source_composition_id}}/instances/{{instance_id}}
{
    deployOrder = "UPGRADE",
    compositionTarget = "{{target_composition_id}}"
}

After instance has been upgraded successfully, it could be retrieved using:

GET /onap/policy/clamp/acm/v2/compositions/{{target_composition_id}}/instances/{{instance_id}}

In success scenario, is it possible to revert the upgrade, using the same endpoint with composition id inverted.

If upgrade fail, the instance is still based to {{source_composition_id}} with deployOrder "UPGRADING" and stateChangeResult "FAILED".

In this scenario, is it possible to retry or rollback the upgrade, with the deployOrder set to "UPGRADE_ROLLBACK".

Retry:

PUT /onap/policy/clamp/acm/v2/compositions/{{source_composition_id}}/instances/{{instance_id}}
{
    deployOrder = "ROLLBACK",
    compositionTarget = "{{target_composition_id}}"
}

Rollback:

PUT /onap/policy/clamp/acm/v2/compositions/{{source_composition_id}}/instances/{{instance_id}}
{
    deployOrder = "UPGRADE_ROLLBACK",
    compositionTarget = "{{target_composition_id}}"
}

Other solutions