The Application Controller (APP-C) manages and controls the life cycle of virtual applications, such as virtual network functions (VNFs), and their components. APP-C receives commands from external OpenECOMP components, such as MSO, DCAE, or the Portal.
A virtual application is composed of the following layers of network technology:
- Service
- Virtual Network Function (VNF)
- Virtual Network Function Component (VNFC)
- Virtual Machine (VM)
A Life Cycle Management (LCM) command may affect one or more of these layers.
For example, a Terminate command applies to all four layers, whereas a Scale command may not apply to the VM layer.
An LCM command is sent as a request to the APP-C using an HTTP POST request, or in a message on OpenECOMP's bus (DMaaP). For each request, the APP-C returns one or more responses:
- An asynchronous command, which is sent as an authorized and valid request, results in at least two discrete response events:
- an accept response, to indicate that the request is accepted for processing
- a final response to indicate the status and outcome of the request processing
An unauthorized or invalid request results in a single ERROR response.
- A synchronous command, such as Lock or Unlock, results in a single response that is either SUCCESS or ERROR.
For more information, see the OpenECOMP Application Controller (APP-C) API Guide.