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
End point, fail and rollback
Solution 1
Migrate using a new endpoint:
PUT /onap/policy/clamp/acm/v2/compositions/{{source_composition_id}}/instances/{{instance_id}}/migrate
{
compositionTarget = "{{target_composition_id}}"
}
After instance has been migrated 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 migration, using the same endpoint with composition id inverted.
If migration fail, the instance is still based to {{source_composition_id}} with deployOrder "MIGRATING" and stateChangeResult "FAILED". In this scenario, is it possible to retry or rollback the migration.
Retry and TimeOut are supported.
Rollback:
PUT /onap/policy/clamp/acm/v2/compositions/{{source_composition_id}}/instances/{{instance_id}}/migrate
{
rollback = "true",
compositionTarget = "{{target_composition_id}}"
}
Solution 2
Migrate using change state endpoint:
PUT /onap/policy/clamp/acm/v2/compositions/{{source_composition_id}}/instances/{{instance_id}}
{
deployOrder = "MIGRATE",
compositionTarget = "{{target_composition_id}}"
}
After instance has been migrated 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 migration, using the same endpoint with composition id inverted.
If migration fail, the instance is still based to {{source_composition_id}} with deployOrder "MIGRATING" and stateChangeResult "FAILED". In this scenario, is it possible to retry or rollback the migration.
Retry and TimeOut are supported.
Rollback:
PUT /onap/policy/clamp/acm/v2/compositions/{{source_composition_id}}/instances/{{instance_id}}
{
deployOrder = "MIGRATION_ROLLBACK",
compositionTarget = "{{target_composition_id}}"
}
Solution 3
Migrate using update endpoint:
POST /onap/policy/clamp/acm/v2/compositions/{{source_composition_id}}/instances/{{instance_id}}
| Code Block | ||||
|---|---|---|---|---|
| ||||
name: ExampleInstance0
version: 1.0.1
compositionId: {{compositionId}}
compositionTarget: {{target_composition_id}}
elements:
709c62b3-8918-41b9-a747-d21eb79c6c23:
id: 709c62b3-8918-41b9-a747-d21eb79c6c23
definition:
name: onap.policy.clamp.ac.element.ExampleAutomationCompositionElement
version: 1.2.3
properties:
propertyExample: new value |
After instance has been migrated 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 migration, using the same endpoint with old properties values and composition id inverted.
If migration fail, the instance is still based to {{source_composition_id}} with deployState "MIGRATING" and stateChangeResult "FAILED". In this scenario, is it possible to retry or rollback the migration.
Retry and TimeOut are supported.
Rollback:
POST /onap/policy/clamp/acm/v2/compositions/{{source_composition_id}}/instances/{{instance_id}}
| Code Block | ||||
|---|---|---|---|---|
| ||||
name: ExampleInstance0
version: 1.0.1
compositionId: {{compositionId}}
compositionTarget: {{target_composition_id}}
rollback: true
elements:
709c62b3-8918-41b9-a747-d21eb79c6c23:
id: 709c62b3-8918-41b9-a747-d21eb79c6c23
definition:
name: onap.policy.clamp.ac.element.ExampleAutomationCompositionElement
version: 1.2.3
properties:
propertyExample: old value |
Final solution
- Migrate using update endpoint:
POST /onap/policy/clamp/acm/v2/compositions/{{source_composition_id}}/instances/{{instance_id}}
"compositionTargetId" and new properties values will be saved in DB and available during migration operation.
| Code Block | ||||
|---|---|---|---|---|
| ||||
name: ExampleInstance0
version: 1.0.1
compositionId: {{compositionId}}
compositionTargetId: {{target_composition_id}}
elements:
709c62b3-8918-41b9-a747-d21eb79c6c23:
id: 709c62b3-8918-41b9-a747-d21eb79c6c23
definition:
name: onap.policy.clamp.ac.element.ExampleAutomationCompositionElement
version: 1.2.3
properties:
propertyExample: new value |
- New MIGRATE message to be sent over Kafka to participant
- During migration operation, the instance will be available to retrieve by source and target composition:
GET /onap/policy/clamp/acm/v2/compositions/{{source_composition_id}}/instances
GET /onap/policy/clamp/acm/v2/compositions/{{source_composition_id}}/instances/{{instance_id}}
GET /onap/policy/clamp/acm/v2/compositions/{{target_composition_id}}/instances/{{instance_id}}
| Code Block | ||||
|---|---|---|---|---|
| ||||
name: ExampleInstance0
version: 1.0.1
compositionId: {{compositionId}}
compositionTargetId: {{target_composition_id}}
deployState: MIGRATING
lockState: LOCKED
elements:
709c62b3-8918-41b9-a747-d21eb79c6c23:
id: 709c62b3-8918-41b9-a747-d21eb79c6c23
definition:
name: onap.policy.clamp.ac.element.ExampleAutomationCompositionElement
version: 1.2.3
deployState: MIGRATING
lockState: LOCKED
properties:
propertyExample: new value |
Note: during migration the instance instance_id is not in target_composition_id yet, so that instance will be not available in "GET /onap/policy/clamp/acm/v2/compositions/{{target_composition_id}}/instances".
- After instance has been migrated successfully, it will be retrieved using:
GET /onap/policy/clamp/acm/v2/compositions/{{target_composition_id}}/instances
GET /onap/policy/clamp/acm/v2/compositions/{{target_composition_id}}/instances/{{instance_id}}
| Code Block | ||||
|---|---|---|---|---|
| ||||
name: ExampleInstance0
version: 1.0.1
compositionId: {{target_composition_id}}
deployState: DEPLOYED
lockState: LOCKED
stateChangeResult: NO_ERROR
elements:
709c62b3-8918-41b9-a747-d21eb79c6c23:
id: 709c62b3-8918-41b9-a747-d21eb79c6c23
definition:
name: onap.policy.clamp.ac.element.ExampleAutomationCompositionElement
version: 1.2.3
deployState: DEPLOYED
lockState: LOCKED
properties:
propertyExample: new value |
Note: The endpoint "GET /onap/policy/clamp/acm/v2/compositions/{{target_composition_id}}/instances/{{instance_id}}" is the suggested endpoint to use for checking the migration result.
- AutomationCompositionElementListener altered to allow participant to listen for migrate message:
void migrate(UUID instanceId, AcElementDeploy element, UUID compositionTargetId, Map<String, Object> properties) throws PfModelException; - If migration fail, the instance is still based to {{source_composition_id}} with deployState "MIGRATING" and stateChangeResult "FAILED".