ETSI NFV-SOL VNF error-handling¶
This document describes how to error-handling VNF in Tacker v2 API.
Note
The content of this document has been confirmed to work using the following VNF Package.
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 Error-handling Procedures¶
As mentioned in Prerequisites, the VNF must be created before performing error-handling.
Details of CLI commands are described in VNF Lifecycle Management with v2 Tacker.
There are some operations to error-handling VNF.
Rollback VNF lifecycle management operation
Fail VNF lifecycle management operation
Retry VNF lifecycle management operation
In order to execute error-handling, it is necessary to specify VNF_LCM_OP_OCC_ID, which is the ID for the target LCM operation. First, the method of specifying the ID will be described.
Identify VNF_LCM_OP_OCC_ID¶
The VNF_LCM_OP_OCC_ID can be obtained via CLI.
Details of CLI commands are described in VNF Lifecycle Management with v2 Tacker.
Before checking the “VNF_LCM_OP_OCC_ID”, you should get VNF_INSTANCE_ID first.
$ openstack vnflcm op list --os-tacker-api-version 2
Result:
+--------------------------------------+-----------------+--------------------------------------+-------------+
| ID | Operation State | VNF Instance ID | Operation |
+--------------------------------------+-----------------+--------------------------------------+-------------+
| a7f80542-faeb-4324-ba82-c6214307e864 | FAILED_TEMP | 385fc2ff-1ef5-42f4-8196-3d913160074d | INSTANTIATE |
+--------------------------------------+-----------------+--------------------------------------+-------------+
Error-handling can be executed only when operationState is FAILED_TMP.
If the Subscription is registered, the above operation trigger that caused the FAILED_TEMP send a ‘Notification’ to the callbackUri of the Subscription.
vnfLcmOpOccId included in this ‘Notification’ corresponds to VNF_LCM_OP_OCC_ID.
See VNF LCM v2 API for details on the APIs used here.
Rollback VNF LCM Operation¶
LCM Operation |
Description of Rollback |
Precondition |
Postcondition |
|---|---|---|---|
Instantiate |
VNFM removes all VMs and resources.
e.g. Tacker executes Heat stack-delete for deletion of the target VM.
|
FAILED_TEMP |
ROLLED_BACK or FAILED_TEMP |
Scale-out |
VNFM reverts changes of VMs and resources specified in the middle of scale-out operation.
As a result, the newest VNFc(VM) is deleted.
e.g. Tacker reverts desired_capacity and executes Heat stack-update.
|
FAILED_TEMP |
ROLLED_BACK or FAILED_TEMP |
Modify |
VNFM reverts the update of the VNF instance information. |
FAILED_TEMP |
ROLLED_BACK or FAILED_TEMP |
Change external connectivity |
VNFM reverts changes of the external connectivity for VNF instances.
e.g. Tacker reverts stack parameters and executes Heat stack-update.
|
FAILED_TEMP |
ROLLED_BACK or FAILED_TEMP |
Change Current VNF Package |
VNFM reverts changes of current vnf package for VNF instances.
e.g. Tacker reverts stack parameters and executes Heat stack-update.
|
FAILED_TEMP |
ROLLED_BACK or FAILED_TEMP |
Note
In some cases, Rollback of Change external connectivity cannot recover the IP address and Port Id of virtual resources. If the operation fails before performing VIM processing: updating stack, the IP address and Port Id will be recovered by its rollback operation. Otherwise, dynamic IP address and Port Id are not recovered by rollback operation.
This manual describes the following operations as use cases for rollback operations.
“Instantiate VNF” fails
Rollback VNF lifecycle management operation
Delete VNF
As shown below, if “Instantiate VNF” fails, “Delete VNF” cannot be executed without executing “Rollback VNF lifecycle management operation”.
$ openstack vnflcm delete VNF_INSTANCE_ID --os-tacker-api-version 2
Result:
Failed to delete vnf instance with ID '385fc2ff-1ef5-42f4-8196-3d913160074d': Other LCM operation of vnfInstance 385fc2ff-1ef5-42f4-8196-3d913160074d is in progress.
Failed to delete 1 of 1 vnf instances.
Therefore, “Rollback VNF lifecycle management operation” with the following CLI command.
$ openstack vnflcm op rollback VNF_LCM_OP_OCC_ID --os-tacker-api-version 2
Result:
Rollback request for LCM operation a7f80542-faeb-4324-ba82-c6214307e864 has been accepted
If “Rollback VNF lifecycle management operation” is successful, then “Delete VNF” is also successful.
$ openstack vnflcm delete VNF_INSTANCE_ID --os-tacker-api-version 2
Result:
Vnf instance '385fc2ff-1ef5-42f4-8196-3d913160074d' is deleted successfully
Fail VNF LCM Operation¶
LCM Operation |
Description of Fail |
Precondition |
Postcondition |
|---|---|---|---|
Instantiate |
Tacker simply changes LCM operation state to “FAILED” on Tacker-DB. |
FAILED_TEMP |
FAILED |
Terminate |
Tacker simply changes LCM operation state to “FAILED” on Tacker-DB. |
FAILED_TEMP |
FAILED |
Heal |
Tacker simply changes LCM operation state to “FAILED” on Tacker-DB. |
FAILED_TEMP |
FAILED |
Scale |
Tacker simply changes LCM operation state to “FAILED” on Tacker-DB. |
FAILED_TEMP |
FAILED |
Modify |
Tacker simply changes LCM operation state to “FAILED” on Tacker-DB. |
FAILED_TEMP |
FAILED |
Change external connectivity |
Tacker simply changes LCM operation state to “FAILED” on Tacker-DB. |
FAILED_TEMP |
FAILED |
Change Current VNF Package |
Tacker simply changes LCM operation state to “FAILED” on Tacker-DB. |
FAILED_TEMP |
FAILED |
This manual describes the following operations as use cases for fail operations.
“Instantiate VNF” fails
Fail VNF lifecycle management operation
Delete VNF
As shown below, if “Instantiate VNF” fails, “Delete VNF” cannot be executed after executing “Fail VNF lifecycle management operation”.
$ openstack vnflcm delete VNF_INSTANCE_ID --os-tacker-api-version 2
Result:
Failed to delete vnf instance with ID '385fc2ff-1ef5-42f4-8196-3d913160074d': Other LCM operation of vnfInstance 385fc2ff-1ef5-42f4-8196-3d913160074d is in progress.
Failed to delete 1 of 1 vnf instances.
Therefore, “Fail VNF lifecycle management operation” with the following CLI command.
$ openstack vnflcm op fail VNF_LCM_OP_OCC_ID \
--fit-width --os-tacker-api-version 2
Result:
+-------------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Field | Value |
+-------------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Error | { |
| | "title": "Stack create failed", |
| | "status": 422, |
| | "detail": "Resource CREATE failed: resources.wifiut5qtngn: resources.VDU1_scale_group.Property error: resources.VDU1_CP1.properties.network: Error validating value 'errornetwork': Unable to find network with name or id |
| | 'errornetwork'" |
| | } |
| ID | a7f80542-faeb-4324-ba82-c6214307e864 |
| Is Automatic Invocation | False |
| Is Cancel Pending | False |
| Links | { |
| | "self": { |
| | "href": "http://127.0.0.1:9890/vnflcm/v2/vnf_lcm_op_occs/a7f80542-faeb-4324-ba82-c6214307e864" |
| | }, |
| | "vnfInstance": { |
| | "href": "http://127.0.0.1:9890/vnflcm/v2/vnf_instances/385fc2ff-1ef5-42f4-8196-3d913160074d" |
| | }, |
| | "retry": { |
| | "href": "http://127.0.0.1:9890/vnflcm/v2/vnf_lcm_op_occs/a7f80542-faeb-4324-ba82-c6214307e864/retry" |
| | }, |
| | "rollback": { |
| | "href": "http://127.0.0.1:9890/vnflcm/v2/vnf_lcm_op_occs/a7f80542-faeb-4324-ba82-c6214307e864/rollback" |
| | }, |
| | "fail": { |
| | "href": "http://127.0.0.1:9890/vnflcm/v2/vnf_lcm_op_occs/a7f80542-faeb-4324-ba82-c6214307e864/fail" |
| | } |
| | } |
| Operation | INSTANTIATE |
| Operation State | FAILED |
| Start Time | 2023-11-14T04:32:57Z |
| State Entered Time | 2023-11-14T04:32:57Z |
| VNF Instance ID | 385fc2ff-1ef5-42f4-8196-3d913160074d |
| grantId | 008eccda-5466-4820-ae76-bdce6e128d8c |
| operationParams | { |
| | "flavourId": "simple" |
| | } |
+-------------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
If “Fail VNF lifecycle management operation” is successful, then “Delete VNF” is also successful.
$ openstack vnflcm delete VNF_INSTANCE_ID --os-tacker-api-version 2
Result:
Vnf instance '385fc2ff-1ef5-42f4-8196-3d913160074d' is deleted successfully
Retry VNF LCM Operation¶
LCM Operation |
Description of Fail |
Precondition |
Postcondition |
|---|---|---|---|
Instantiate |
VNFM retries a Instantiate operation. |
FAILED_TEMP |
COMPLETED or FAILED_TEMP |
Terminate |
VNFM retries a Terminate operation. |
FAILED_TEMP |
COMPLETED or FAILED_TEMP |
Heal |
VNFM retries a Heal operation. |
FAILED_TEMP |
COMPLETED or FAILED_TEMP |
Scale |
VNFM retries a Scale operation. |
FAILED_TEMP |
COMPLETED or FAILED_TEMP |
Modify |
VNFM retries a Modify operation. |
FAILED_TEMP |
COMPLETED or FAILED_TEMP |
Change external connectivity |
VNFM retries a Change external connectivity operation. |
FAILED_TEMP |
COMPLETED or FAILED_TEMP |
Change Current VNF Package |
VNFM retries a Change Current VNF Package operation. |
FAILED_TEMP |
COMPLETED or FAILED_TEMP |
This manual describes the following operations as use cases for retry operations.
“Instantiate VNF” fails
Retry VNF lifecycle management operation
As shown below, if “Instantiate VNF” fails, If you want re-execute previous(failed) operation , you execute “Retry” operation.
Therefore, “Retry VNF lifecycle management operation” with the following CLI command.
$ openstack vnflcm op retry VNF_LCM_OP_OCC_ID --os-tacker-api-version 2
Result:
Retry request for LCM operation a7f80542-faeb-4324-ba82-c6214307e864 has been accepted
If “Retry VNF lifecycle management operation” is successful, then another LCM can be operational.
Error-handling of MgmtDriver¶
Error-handling includes Retry, Rollback and Fail operations.
For the fail operation, it will not perform LCM when it is executed, so there is no need to use MgmtDriver.
For the retry operation, it will perform the LCM again when it is executed, so as long as the LCM is configured with MgmtDriver, the MgmtDriver will also be called during the retry operation, and no additional configuration is required.
For the rollback operation, because there is no definition of
rollback_startandrollback_endin6.7 Interface Typesof NFV-SOL001 v2.6.1, so when the rollback operation is performed, MgmtDriver will not be called.
The VNFD in the VNF Package must be modified before calling MgmtDriver in the rollback operation.
Note
In the MgmtDriver, the user saves the data that needs to be kept
when the LCM fails in the user_script_err_handling_data variable.
It is saved in the corresponding VNF_LCM_OP_OCC, and can be viewed through
Show VNF LCM OP OCC.
During error-handling (retry or rollback), use the data in the
user_script_err_handling_data variable to perform corresponding
processing.
Modifications of VNF Package¶
Users need to make the following modifications when creating a VNF Package.
The rollback operation currently supports multiple Rollback VNF LCM Operation. The following takes the rollback operations of instantiate and scale-out as examples to demonstrate how to modify VNFD.
Note
The following provides the sample files v2_sample2_df_simple.yaml and
v2_sample2_types.yaml that need to be modified, which are stored in
the Definitions directory of the VNF Package.
v2_sample2_df_simple.yamlcorresponds to4. Topology Template File with Deployment Flavourin VNF Descriptor (VNFD) based on ETSI NFV-SOL001.v2_sample2_types.yamlcorresponds to2. User Defined Types Definition Filein VNF Descriptor (VNFD) based on ETSI NFV-SOL001.
In
v2_sample2_df_simple.yaml,xxx_rollback_startandxxx_rollback_endneed to be added undertopology_template.node_templates.VNF.interfaces.Vnflcm.The following is the content of
v2_sample2_df_simple.yaml, the unmodified part is replaced by “...” :topology_template: ... node_templates: VNF: type: company.provider.VNF properties: flavour_description: A simple flavour interfaces: Vnflcm: instantiate_start: implementation: mgmt-driver-script instantiate_end: implementation: mgmt-driver-script heal_start: implementation: mgmt-driver-script heal_end: implementation: mgmt-driver-script scale_start: implementation: mgmt-driver-script scale_end: implementation: mgmt-driver-script terminate_start: implementation: mgmt-driver-script terminate_end: implementation: mgmt-driver-script change_external_connectivity_start: implementation: mgmt-driver-script change_external_connectivity_end: implementation: mgmt-driver-script modify_information_start: implementation: mgmt-driver-script modify_information_end: implementation: mgmt-driver-script instantiate_rollback_start: implementation: mgmt-driver-script instantiate_rollback_end: implementation: mgmt-driver-script scale_rollback_start: implementation: mgmt-driver-script scale_rollback_end: implementation: mgmt-driver-script artifacts: mgmt-driver-script: description: Sample MgmtDriver Script type: tosca.artifacts.Implementation.Python file: ../Scripts/mgmt_driver_script.py
Note
If some definitions of
xxx_startandxxx_endare added in VNFD, correspondingxxx_startandxxx_endfunctions must also be added in MgmtDriver.In
v2_sample2_types.yaml, the definition ofinterface_typesneeds to be added, and the definition oftypeneeds to be modified undernode_types.company.provider.VNF.interfaces.Vnflcm.The following is the content of
v2_sample2_types.yaml, the unmodified part is replaced by “...” :interface_types: sample.test.Vnflcm: derived_from: tosca.interfaces.nfv.Vnflcm instantiate_start: description: Invoked before instantiate instantiate_end: description: Invoked after instantiate heal_start: description: Invoked before heal heal_end: description: Invoked after heal scale_start: description: Invoked before scale scale_end: description: Invoked after scale terminate_start: description: Invoked before terminate terminate_end: description: Invoked after terminate change_external_connectivity_start: description: Invoked before change_external_connectivity change_external_connectivity_end: description: Invoked after change_external_connectivity modify_information_start: description: Invoked before modify_information modify_information_end: description: Invoked after modify_information instantiate_rollback_start: description: Invoked before instantiate_rollback instantiate_rollback_end: description: Invoked after instantiate_rollback scale_rollback_start: description: Invoked before scale_rollback scale_rollback_end: description: Invoked after scale_rollback node_types: company.provider.VNF: ... interfaces: Vnflcm: type: sample.test.Vnflcm
After the above modification, MgmtDriver can also be called in error-handling.
Note
In the process of error-handling, the specific action of MgmtDriver needs to be customized by the user or provider.
