Add options for on-end action¶

Use Cases¶

• All users want Blazar to be punctual for guaranteeing fairness for all leases.
• A user wants to snapshot the instances of the lease if the workload does not finish in the lease period. Then, the user will resume the snapshotted instances and restart the workload at the next lease period.
• A user wants to use instances just temporarily and wants those instances to be auto-deleted at the end of the lease period.

Alternatives¶

Use NOT the “before_end_lease” BUT the “end_lease” event for the actions like snapshot. The end_lease event is triggered at the end of a lease for now. Change that to be triggered at the specific time window prior to the end of a lease. Make the length of the time window configurable.

This change may complicate event handling because the end_lease event can trigger multiple actions, e.g., take snapshot and then delete the instance, while the before_end_lease solution keeps one-event-to-one-action relationship. Therefore, we prefer the before_end_lease solution.

Data model impact¶

• A new attribute “before_end_action” will be added to the reservation table.

REST API impact¶

• Plan to update only v2 API and not to support before_end_lease related capabilities for v1 API.

• URL: POST /v2/leases

  • Add a new parameter “before_end_action”

  • Change the parameter “before_end_lease” to “before_end_date”. This change is for aligning the terminology with the other parameters.

    Example:

    {
        "name": "lease_foo",
        "start_date": "2017-3-21 15:00",
        "end_date": "2017-03-24 15:00",
        "before_end_date": "2017-3-24 14:00",
        "reservations": [
            {
                "resource_id": "1234",
                "min": 1,
                "max": 3,
                "resource_type": "physical:host",
                "hypervisor_properties": "[\">=\", \"$memory_mb\", \"4096\"]",
                "before_end_action": "snapshot"
            }
        ],
        "events": []
    }
    

• URL: PUT /v2/leases

  Same changes as for the POST request.

Security impact¶

None.

Notifications impact¶

None.

Other end user impact¶

None.

Performance Impact¶

None.

Other deployer impact¶

• New config options will be added in the physical:host group:
  • before_end_action: Configure default action for the before_end_lease.
  • hours_before_end_lease: Configure default hours (prior to the end_lease) that triggers the before_end_lease action.

Developer impact¶

None.

Assignee(s)¶

Primary assignee:

hiro-kobayashi

Work Items¶

• STEP1: Change the behavior at the end of a lease to force-delete running instances.
• STEP2: Change the before_end_lease event to support configurable actions.
• STEP3: Change REST APIs.