4. High level architecture and general features¶
4.1. Architecture Overview¶
Fig. 4.1 Resource Reservation Architecture¶
Fig. 4.1 shows the high level architecture for the resource reservation use cases. Reserved resources are guaranteed for a given user/client for the period expressed by start and end time. User/client represents the requestor and the consequent consumer of the reserved resources and correspond to the NFVO or VNFM in ETSI NFV terminology.
Note: in this document only reservation requests from NFVO are considered.
4.2. General Features¶
This section provides a list of features that need to be developed in the Promise project.
- Resource capacity management
- Discovery of available resource capacity in resource providers
- Monitoring of available resource capacity in resource providers
- Update available resource capacity as a result of new or expired reservations, addition/removal of resources. Note: this is a VIM internal function, not an operation in the VIM northbound interface.
- Resource reservation
- Set start time and end time for allocation
- Increase/decrease reserved resource’s capacity
- Update resource reservations, e.g. add/remove reserved resources
- Terminate an allocated resource due to the end time of a reservation
- VIM northbound interfaces
- Receive/Reply resource reservation requests
- Receive/Reply resource capacity management requests
- Receive/Reply resource allocation requests for reserved resources when start time arrives
- Subscribe/Notify resource reservation event
- Notify reservation error or process completion prior to reservation start
- Notify remaining time until termination of a resource due to the end time of a reservation
- Notify termination of a resource due to the end time of a reservation
- Receive/Reply queries on available resource capacity
- Subscribe/Notify changes in available resource capacity
4.3. High level northbound interface specification¶
4.3.1. Resource Capacity Management¶
Fig. 4.2 Resource capacity management message flow: notification of capacity change¶
Fig. 4.2 shows a high level flow for a use case of resource capacity management. In this example, the VIM notifies the NFVO of capacity change after having received an event regarding a change in capacity (e.g. a fault notification) from the NFVI. The NFVO can also retrieve detailed capacity information using the Query Capacity Request interface operation.
Fig. 4.3 Resource capacity management message flow: query of capacity density¶
Fig. 4.3 shows a high level flow for another use case of resource capacity management. In this example, the NFVO queries the VIM about the actual capacity to instantiate a certain resource according to a certain template, for example a VM according to a certain flavor. In this case the VIM responds with the number of VMs that could be instantiated according to that flavor with the currently available capacity.
4.3.2. Resource Reservation¶
Fig. 4.4 Resource reservation flow¶
Fig. 4.4 shows a high level flow for a use case of resource reservation. The main steps are:
- The NFVO sends a resource reservation request to the VIM using the Create Resource Reservation Request interface operation.
- The NFVO gets a reservation identifier reservation associated with this request in the reply message
- Using the reservation identifier reservation, the NFVO can query/update/terminate a resource reservation using the corresponding interface operations
- The NFVO is notified that the resource reservation is terminated due to the end time of the reservation
4.4. Information elements¶
4.4.1. Resource Capacity Management¶
4.4.1.1. Notify Capacity Change Event¶
The notification change message shall include the following information elements:
| Name | Type | Description |
|---|---|---|
| Notification | Identifier | Identifier issued by the VIM for the capacity change event notification |
| Zone | Identifier | Identifier of the zone where capacity has changed |
| Used/Reserved/Total Capacity | List | Used, reserved and total capacity information regarding the resource items subscribed for notification for which capacity change event occurred |
4.4.1.2. Query Resource Capacity Request¶
The capacity management query request message shall include the following information elements:
| Name | Type | Description |
|---|---|---|
| Zone | Identifier | Identifier of the zone where capacity is requested |
| Attributes | List | Attributes of resource items to be notified regarding capacity change events |
| Resources | List | Identifiers of existing resource items to be queried regarding capacity info (such as images, flavors, virtual containers, networks, physical machines, etc.) |
The capacity management query request message may also include the following information element:
| Name | Type | Description |
|---|---|---|
| Flavor | Identifier | Identifier that is passed in the request to obtain information of the number of virtual resources that can be instantiated according to this flavor with the available capacity |
4.4.1.3. Query Resource Capacity Reply¶
The capacity management query reply message shall include the following information elements:
| Name | Type | Description |
|---|---|---|
| Zone | Identifier | Identifier of the zone where capacity is requested |
| Used/Reserved/Total Capacity | List | Used, reserved and total capacity information regarding each of the resource items requested to check for capacity |
The detailed specification of the northbound interface for Capacity Management in provided in section 5.1.1.
4.4.2. Resource Reservation¶
4.4.2.1. Create Resource Reservation Request¶
The create resource reservation request message shall include the following information elements:
| Name | Type | Description |
|---|---|---|
| Start | Timestamp | Start time for consumption of the reserved resources |
| End | Timestamp | End time for consumption of the reserved resources |
| Expiry | Timestamp | If not all reserved resources are allocated between start time and expiry, the VIM shall release the corresponding resources [1] |
| Amount | Number | Amount of the resources per resource item type (i.e. compute/network/storage) that need to be reserved |
| Zone | Identifier | The zone where the resources need(s) to be reserved |
| Attributes | List | Attributes of the resources to be reserved such as DPDK support, hypervisor, network link bandwidth, affinity rules, etc. |
| Resources | List | Identifiers of existing resource items to be reserved (such as images, flavors, virtual containers, networks, physical machines, etc.) |
| [1] | Expiry is a period around start time within which, the allocation process must take place. If allocation process does not start within the expiry period, the reservation becomes invalid and VIM should release the resources |
4.4.2.2. Create Resource Reservation Reply¶
The create resource reservation reply message shall include the following information elements:
| Name | Type | Description |
|---|---|---|
| Reservation | Identifier | Identification of the reservation instance. It can be used by a consumer to modify the reservation later, and to request the allocation of the reserved resources. |
| Message | Text | Output message that provides additional information about the create resource reservation request (e.g. may be a simple ACK if the request is being background processed by the VIM) |
4.4.2.3. Notify Reservation Event¶
The notification reservation event message shall include the following information elements:
| Name | Type | Description |
|---|---|---|
| Reservation | Identifier | Identification of the reservation instance triggering the event |
| Notification | Identifier | Identification of the resource event notification issued by the VIM |
| Message | Text | Message describing the event |
The detailed specification of the northbound interface for Resource Reservation is provided in section 5.1.2.
