Extra specs for instance reservation¶

Use Cases¶

For NFV area, some kinds of instances need to run on specific hypervisors, like DPDK, SR-IOV, etc. If the instance reservation doesn’t support extra specs, reserved instances could be scheduled to non-DPDK hypervisors though the user want the instance to be scheduled to DPDK hypervisors.

For HPC area, GPGPU is common in the area. So when users reserve instances, they may want to request GPU instances.

Alternatives¶

An user directly specifies the list of hypervisors which have the specific features in a request body. Users check which hypervisors have the features before they create instance reservations, then they decide which hypervisors they want to use.

This approach could be easier to implement than the proposed change since what Blazar needs to do is just pick up hypervisors from the list. However, the admin can change ComputeHostExtraCapability anytime. When a specific feature users want to use is changed, the user have to send a new list of hypervisors again. Additionally, a cloud may be configured to forbid users from looking up hosts and their extra capabilities.

Data model impact¶

A resource_properties column is added to the InstanceReservations table. This column stores the raw string of the resource_properties sent by users.

The change for the InstanceReservations table is as follows:

ALTER TABLE instance_reservations ADD
    resource_properties MEDIUMTEXT AFTER affinity;

NULL is assigned to the column for the upgrade from Pike to later.

REST API impact¶

• URL: POST /v1/leases
  • Introduce the resource_properties key in virtual:instance resource_type

Request Example:

{
  "name": "instance-reservation-1",
  "reservations": [
    {
      "resource_type": "virtual:instance",
      "vcpus": 4,
      "memory_mb": 4096,
      "disk_gb": 10,
      "amount": 5,
      "affinity": False,
      "resource_properties": {
          "property_key1": "value1",
          "property_key2": "value2"
      }
    }
   ],
  "start": "2020-05-17 09:00"
  "end": "2020-05-17 10:00",
  "events": []
}

Response Example:

{
  "leases": {
    "reservations": [
      {
        "id": "reservation-id",
        "status": "pending",
        "lease_id": "lease-id-1",
        "resource_id": "resource_id",
        "resource_type": "virtual:instance",
        "vcpus": 4,
        "memory_mb": 4096,
        "disk_gb": 10,
        "amount": 5,
        "affinity": False,
        "resource_properties": {
           "property_key1": "value1",
           "property_key2": "value2"
        }
        "created_at": "2017-05-01 10:00:00",
        "updated_at": "2017-05-01 11:00:00",
      }],
   ..snippet..
  }
}

• URL: GET /v1/leases
• URL: GET /v1/leases/{lease-id}
• URL: PUT /v1/leases/{lease-id}
• URL: DELETE /v1/leases/{lease-id}
  • The change is the same as POST /v1/leases

Security impact¶

None

Notifications impact¶

None

Other end user impact¶

python-blazarclient needs to support resource_properties parameter in lease handling commands.

Performance Impact¶

None

Other deployer impact¶

None

Developer impact¶

None

Assignee(s)¶

Primary assignee:

muroi-masahito

Other contributors:

None

Work Items¶

• Add resource_properties column to InstanceReservation table
• Support resource_properties key in instance reservation plugin
• Add re-allocation logic to ComputeHostExtraCapability management
• Support resource_properties parameter at python-blazarclient