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diff --git a/docs/manual_use_case.rst b/docs/manual_use_case.rst index ed22808..9f04418 100644 --- a/docs/manual_use_case.rst +++ b/docs/manual_use_case.rst @@ -16,54 +16,80 @@ :local: Manual Scale Out Use Case -================================== +========================= -Since its Beijing Release, ONAP will support the ability to manually scale -out VNF Components. Below is the Sequence Diagram for how Manual Scale Out -will work in ONAP. +In the Casablanca release, ONAP will support the ability to both manually and +automatically scale out a VNF component. Below is the sequence diagram +for how scaling will work. -|image0| +|scale_out_design_time| + +|scale_out_run_time| Description of Workflow ---------------------------------------------- +----------------------- + +At a high level the way Scale Out will work is: + +1. ``VF_Modules`` (VNFC’s) may be scaled out with either one of two methods: + + a. Using VID, the operator will choose to scale out a VNFC by picking + a ``VF_Module`` to scale + b. An operator may define an operating policy (and associated guard + policies) to trigger a scaling operation automatically. -At a high level the way Manual Scale Out will work is: + * As an example, the operating policy may be when the output of an + application load balancer crosses a bandwidth threshold, then increase + the number of instances of the application. + * Examples of a guard policies: - 1. Using VID, the operator will choose to scale out a VNFC by picking a - VF_Module to scale and choosing which controller is responsible for - that VNF. - 2. VID sends the Scale Out Request to SO. - 3. When SO receives the Scaling request it will first send a request to - the appropriate controller (APPC or SDNC) to execute a Healthcheck on the - VNF. - 4. Once the Healthcheck has been run, SO executes the Heat Template - associated with the VF Module requested by the VID Operator. - 5. After the new component(s) have been instantiated SO calls the - responsible controller (via DMaaP) to configure the new instances. - 6. Finally a Healthcheck is run to ensure that the entire VNF is Operating - as it should. + 1. If a scaling operation has run within the past X minutes, then do + not scale. + 2. If the number of instance is <= ``MIN_INSTANCES`` + or >= ``MAX_INSTANCES``, then do not scale. + +2. VID or Policy sends the Scale Out Request to SO. +3. When SO receives the Scaling request it will first send a request to the + appropriate controller (APPC or SDNC) to execute a health check on the VNF. +4. Once the health check has been run, SO executes the Heat Template associated + with the VF Module requested by the VID Operator or the operational policy. +5. After the new component(s) have been instantiated SO calls the responsible + controller (via DMaaP) to configure the new instances using Ansible, Chef, + or Netconf. +6. Finally a health check is run to ensure that the entire VNF is Operating + as it should. VNF Impacts ------------------------- +----------- For VNFs to make use of the Manual Scaling Capabilities of ONAP, they must support the following functionality: - 1. VNFs must support a Healthcheck as described in: `The Management Section of the ONAP VNF Guidelines <http://onap.readthedocs.io/en/latest/submodules/vnfrqts/requirements.git/docs/Chapter7.html#vnf-rest-apis>`_. + 1. VNFs must support a Healthcheck as described in: + :doc:`The Management Section of the ONAP VNF Guidelines<../../../requirements.git/docs/Chapter7/Configuration-Management.html>`. + + a. R-41430 is the requirement dictating the need for VNF Healthchecks. + b. The health check may be supported using REST, Ansible, or Chef + + * REST health check requirements can be found in the + :doc:`REST APIs section<../../../requirements.git/docs/Chapter7/Configuration-Management.html#vnf-rest-apis>` + * The Ansible health check playbook can be found in the + :doc:`Ansible Playbook Requirements section<../../../requirements.git/docs/Chapter7/Configuration-Management.html#vnf-rest-apis#ansible-playbook-requirements>` - a. R-31809 is the requirement dictating the need for VNF Healthchecks. - b. The Ansible Healthcheck Playbook description may be found in `The Ansible Standards and Capabilities Section <http://onap.readthedocs.io/en/latest/submodules/vnfrqts/requirements.git/docs/Chapter7.html#ansible-standards-and-capabilities>`_. + 2. R-43413 states that a "VNF MUST utilize a modular Heat Orchestration + Template design to support scaling". The description of this design may + be found in the + :doc:`ONAP VNF Modularity Overview section<../../../requirements.git/docs/Chapter5/Heat/ONAP Heat Orchestration Templates Overview.html#onap-vnf-modularity-overview>` + of the Heat Requirements. - 2. VNF Heat Templates must be built according the `VNF Modularity Rules <http://onap.readthedocs.io/en/latest/submodules/vnfrqts/requirements.git/docs/Chapter4.html#d-vnf-modularity>`_. + a. The ``VF_Module`` to be scaled must be built according to the VNF + Modularity Rules for Incremental Modules - a. The VF_Module to be scaled must be built according the VNF - Modularity Rules for Incremental Modules. + 3. Configuration of the VNF must be done via NETCONF, Chef, or Ansible as + described in the :doc:`Configuration Management<./../../requirements.git/docs/Chapter7/Configuration-Management.html#configuration-management>` - 3. Configuration of the VNF must be done via NETCONF, Chef, or Ansible - as described in `Configuration Management <http://onap.readthedocs.io/en/latest/submodules/vnfrqts/requirements.git/docs/Chapter7.html#c-configuration-management>`_. +.. |scale_out_design_time| image:: manual_scale_out_design_time.png +.. |scale_out_run_time| image:: manual_scale_out_run_time.png -.. |image0| image:: Scale_Out_Workflow.png - :width: 8in - :height: 9in |