ETSI NFV-SOL VNF Scaling¶
This document describes how to scale VNF in Tacker v2 API.
Note
The content of this document has been confirmed to work using the following VNF Package.
Overview¶
The diagram below shows an overview of the VNF scaling.
Request scale VNF
A user requests tacker-server to scale a VNF or all VNFs with tacker-client by requesting
scale VNF.Call OpenStack Heat API
Upon receiving a request from tacker-client, tacker-server redirects it to tacker-conductor. In tacker-conductor, the request is redirected again to an appropriate infra-driver (in this case OpenStack infra-driver) according to the contents of the instantiate parameters. Then, OpenStack infra-driver calls OpenStack Heat APIs.
Change the number of VMs
OpenStack Heat change the number of VMs according to the API calls.
Note
Scale-in operation deletes VNF from the last registered VM.
Prerequisites¶
The following packages should be installed:
tacker
python-tackerclient
Execute up to “Instantiate VNF” in the procedure of ETSI NFV-SOL VNF Deployment as VM with LCM Operation User Data. In other words, the procedure after “Terminate VNF” is not executed.
VNF Scaling Procedure¶
As mentioned in Prerequisites, the VNF must be instantiated before performing scaling.
Details of CLI commands are described in VNF Lifecycle Management with v2 Tacker.
There are two main methods for VNF scaling.
Scale out VNF
Scale in VNF
How to Identify ASPECT_ID¶
In order to execute scaling, it is necessary to specify ASPECT_ID, which is the ID for the target scaling group. First, the method of specifying the ID will be described.
ASPECT_ID is described in VNFD included in the VNF Package. In the following VNFD excerpt, VDU1_scale corresponds to ASPECT_ID.
node_templates:
VDU1:
type: tosca.nodes.nfv.Vdu.Compute
properties:
name: VDU1
description: VDU1 compute node
vdu_profile:
min_number_of_instances: 1
max_number_of_instances: 3
capabilities:
virtual_compute:
properties:
requested_additional_capabilities:
properties:
requested_additional_capability_name: m1.tiny
support_mandatory: true
target_performance_parameters:
entry_schema: test
virtual_memory:
virtual_mem_size: 512 MB
virtual_cpu:
num_virtual_cpu: 1
virtual_local_storage:
- size_of_storage: 3 GB
requirements:
- virtual_storage: VDU1-VirtualStorage
...snip VNFD...
policies:
- scaling_aspects:
type: tosca.policies.nfv.ScalingAspects
properties:
aspects:
VDU1_scale:
name: VDU1_scale
description: VDU1 scaling aspect
max_scale_level: 2
step_deltas:
- delta_1
- VDU1_initial_delta:
type: tosca.policies.nfv.VduInitialDelta
properties:
initial_delta:
number_of_instances: 1
targets: [ VDU1 ]
- VDU1_scaling_aspect_deltas:
type: tosca.policies.nfv.VduScalingAspectDeltas
properties:
aspect: VDU1_scale
deltas:
delta_1:
number_of_instances: 1
targets: [ VDU1 ]
- instantiation_levels:
type: tosca.policies.nfv.InstantiationLevels
properties:
levels:
instantiation_level_1:
description: Smallest size
scale_info:
VDU1_scale:
scale_level: 0
instantiation_level_2:
description: Largest size
scale_info:
VDU1_scale:
scale_level: 2
default_level: instantiation_level_1
- VDU1_instantiation_levels:
type: tosca.policies.nfv.VduInstantiationLevels
properties:
levels:
instantiation_level_1:
number_of_instances: 1
instantiation_level_2:
number_of_instances: 3
targets: [ VDU1 ]
...snip VNFD...
Note
See NFV-SOL001 v2.6.1 annex A.6 for details about ASPECT_ID.
How to Scale Out VNF¶
Execute Scale CLI command and check the number of stacks before and after scaling. This is to confirm that the number of stacks has increased after Scale-out. See Heat CLI reference. for details on Heat CLI commands.
Stack information before scale-out:
$ openstack stack list --nested -c 'ID' -c 'Stack Name' -c 'Stack Status' \
-c 'Parent' --os-tacker-api-version 2
Result:
+--------------------------------------+--------------------------------------------------------------+-----------------+--------------------------------------+
| ID | Stack Name | Stack Status | Parent |
+--------------------------------------+--------------------------------------------------------------+-----------------+--------------------------------------+
| f4221c17-0b42-41c8-af4e-66b15a730275 | vnf-df9150a0-8679-4b14-8cbc-9d2d6606ca7c-VDU1-0-tnyubgoik7ib | CREATE_COMPLETE | cbf6a703-f8fc-441a-9e9d-4f5f723a1e69 |
| 4533da6b-df2e-44bc-b52c-83c1db74aa3f | vnf-df9150a0-8679-4b14-8cbc-9d2d6606ca7c-VDU2-0-5whajpoqh5uh | CREATE_COMPLETE | cbf6a703-f8fc-441a-9e9d-4f5f723a1e69 |
| cbf6a703-f8fc-441a-9e9d-4f5f723a1e69 | vnf-df9150a0-8679-4b14-8cbc-9d2d6606ca7c | CREATE_COMPLETE | None |
+--------------------------------------+--------------------------------------------------------------+-----------------+--------------------------------------+
Scale-out VNF can be executed by the following CLI command.
$ openstack vnflcm scale --type SCALE_OUT --aspect-id VDU1_scale \
--additional-param-file param_file VNF_INSTANCE_ID --os-tacker-api-version 2
Result:
Scale request for VNF Instance df9150a0-8679-4b14-8cbc-9d2d6606ca7c has been accepted.
Stack information after scale-out:
$ openstack stack list --nested -c 'ID' -c 'Stack Name' -c 'Stack Status' \
-c 'Parent' --os-tacker-api-version 2
Result:
+--------------------------------------+--------------------------------------------------------------+-----------------+--------------------------------------+
| ID | Stack Name | Stack Status | Parent |
+--------------------------------------+--------------------------------------------------------------+-----------------+--------------------------------------+
| 10a627b8-afde-4ecc-b44a-2200b733ea2e | vnf-df9150a0-8679-4b14-8cbc-9d2d6606ca7c-VDU1-1-5vvpoq7l2c2k | CREATE_COMPLETE | cbf6a703-f8fc-441a-9e9d-4f5f723a1e69 |
| f4221c17-0b42-41c8-af4e-66b15a730275 | vnf-df9150a0-8679-4b14-8cbc-9d2d6606ca7c-VDU1-0-tnyubgoik7ib | UPDATE_COMPLETE | cbf6a703-f8fc-441a-9e9d-4f5f723a1e69 |
| 4533da6b-df2e-44bc-b52c-83c1db74aa3f | vnf-df9150a0-8679-4b14-8cbc-9d2d6606ca7c-VDU2-0-5whajpoqh5uh | UPDATE_COMPLETE | cbf6a703-f8fc-441a-9e9d-4f5f723a1e69 |
| cbf6a703-f8fc-441a-9e9d-4f5f723a1e69 | vnf-df9150a0-8679-4b14-8cbc-9d2d6606ca7c | UPDATE_COMPLETE | None |
+--------------------------------------+--------------------------------------------------------------+-----------------+--------------------------------------+
Stack details:
$ openstack stack resource list --filter type=VDU1.yaml cbf6a703-f8fc-441a-9e9d-4f5f723a1e69
+---------------+--------------------------------------+---------------+-----------------+----------------------+
| resource_name | physical_resource_id | resource_type | resource_status | updated_time |
+---------------+--------------------------------------+---------------+-----------------+----------------------+
| VDU1-0 | f4221c17-0b42-41c8-af4e-66b15a730275 | VDU1.yaml | UPDATE_COMPLETE | 2023-11-10T04:16:05Z |
| VDU1-1 | 10a627b8-afde-4ecc-b44a-2200b733ea2e | VDU1.yaml | CREATE_COMPLETE | 2023-11-10T04:16:04Z |
+---------------+--------------------------------------+---------------+-----------------+----------------------+
$ openstack stack resource list --filter type=OS::Nova::Server f4221c17-0b42-41c8-af4e-66b15a730275
+---------------+--------------------------------------+------------------+-----------------+----------------------+
| resource_name | physical_resource_id | resource_type | resource_status | updated_time |
+---------------+--------------------------------------+------------------+-----------------+----------------------+
| VDU1 | 3395b07e-8c2e-4fb8-a652-f180d03ab284 | OS::Nova::Server | CREATE_COMPLETE | 2023-11-10T02:58:48Z |
+---------------+--------------------------------------+------------------+-----------------+----------------------+
$ openstack stack resource list --filter type=OS::Nova::Server 10a627b8-afde-4ecc-b44a-2200b733ea2e
+---------------+--------------------------------------+------------------+-----------------+----------------------+
| resource_name | physical_resource_id | resource_type | resource_status | updated_time |
+---------------+--------------------------------------+------------------+-----------------+----------------------+
| VDU1 | 3851c17e-ff76-445f-8286-12e4e1b0c125 | OS::Nova::Server | CREATE_COMPLETE | 2023-11-10T04:16:06Z |
+---------------+--------------------------------------+------------------+-----------------+----------------------+
It can be seen that the child-stack (ID: 10a627b8-afde-4ecc-b44a-2200b733ea2e) with the parent-stack (ID: cbf6a703-f8fc-441a-9e9d-4f5f723a1e69) is increased by the scaling out operation.
How to Scale in VNF¶
Execute Scale CLI command and check the number of stacks before and after scaling. This is to confirm that the number of stacks has decreased after Scale-in. See Heat CLI reference. for details on Heat CLI commands.
Stack information before scale-in:
$ openstack stack list --nested -c 'ID' -c 'Stack Name' -c 'Stack Status' \
-c 'Parent' --os-tacker-api-version 2
Result:
+--------------------------------------+--------------------------------------------------------------+-----------------+--------------------------------------+
| ID | Stack Name | Stack Status | Parent |
+--------------------------------------+--------------------------------------------------------------+-----------------+--------------------------------------+
| 10a627b8-afde-4ecc-b44a-2200b733ea2e | vnf-df9150a0-8679-4b14-8cbc-9d2d6606ca7c-VDU1-1-5vvpoq7l2c2k | CREATE_COMPLETE | cbf6a703-f8fc-441a-9e9d-4f5f723a1e69 |
| f4221c17-0b42-41c8-af4e-66b15a730275 | vnf-df9150a0-8679-4b14-8cbc-9d2d6606ca7c-VDU1-0-tnyubgoik7ib | UPDATE_COMPLETE | cbf6a703-f8fc-441a-9e9d-4f5f723a1e69 |
| 4533da6b-df2e-44bc-b52c-83c1db74aa3f | vnf-df9150a0-8679-4b14-8cbc-9d2d6606ca7c-VDU2-0-5whajpoqh5uh | UPDATE_COMPLETE | cbf6a703-f8fc-441a-9e9d-4f5f723a1e69 |
| cbf6a703-f8fc-441a-9e9d-4f5f723a1e69 | vnf-df9150a0-8679-4b14-8cbc-9d2d6606ca7c | UPDATE_COMPLETE | None |
+--------------------------------------+--------------------------------------------------------------+-----------------+--------------------------------------+
Scale-in VNF can be executed by the following CLI command.
$ openstack vnflcm scale --type SCALE_IN --aspect-id VDU1_scale \
--additional-param-file param_file VNF_INSTANCE_ID --os-tacker-api-version 2
Result:
Scale request for VNF Instance df9150a0-8679-4b14-8cbc-9d2d6606ca7c has been accepted.
Stack information after scale-in:
$ openstack stack list --nested -c 'ID' -c 'Stack Name' -c 'Stack Status' \
-c 'Parent' --os-tacker-api-version 2
Result:
+--------------------------------------+--------------------------------------------------------------+-----------------+--------------------------------------+
| ID | Stack Name | Stack Status | Parent |
+--------------------------------------+--------------------------------------------------------------+-----------------+--------------------------------------+
| f4221c17-0b42-41c8-af4e-66b15a730275 | vnf-df9150a0-8679-4b14-8cbc-9d2d6606ca7c-VDU1-0-tnyubgoik7ib | UPDATE_COMPLETE | cbf6a703-f8fc-441a-9e9d-4f5f723a1e69 |
| 4533da6b-df2e-44bc-b52c-83c1db74aa3f | vnf-df9150a0-8679-4b14-8cbc-9d2d6606ca7c-VDU2-0-5whajpoqh5uh | UPDATE_COMPLETE | cbf6a703-f8fc-441a-9e9d-4f5f723a1e69 |
| cbf6a703-f8fc-441a-9e9d-4f5f723a1e69 | vnf-df9150a0-8679-4b14-8cbc-9d2d6606ca7c | UPDATE_COMPLETE | None |
+--------------------------------------+--------------------------------------------------------------+-----------------+--------------------------------------+
There were two child-stacks(ID: f4221c17-0b42-41c8-af4e-66b15a730275 and ID: 10a627b8-afde-4ecc-b44a-2200b733ea2e) with a parent-stack(ID: cbf6a703-f8fc-441a-9e9d-4f5f723a1e69), it can be seen that one of them is decreased by the Scale-in operation.
