A Controller manages the state of a single Resource (Application , Infrastructure, or Network). It executes the Resource's configuration and instantiation, and is the primary agent in ongoing management, such as control loop actions, migration, and scaling.  All of these actions involve executing workflows (recipes) obtained from Service Design and Creation (SDC). In addition, the Controller reports the status of each workflow execution to both the Active and Available Inventory (AAI) and the Master Service Orchestrator (MSO).

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A Network Controller instantiates a Virtual Network Function , by carrying out its network configuration workflow and reporting the resulting status (to both AAI and MSO). 

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Application Controllers

The MSO sends requests to the Application Controllers to obtain the application-specific component of the Service workflow from SDC and to execute the orchestration workflow.  The MSO continues to be responsible for ensuring that the Application Controller successfully completes its Resource configuration as defined by the workflow.

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OpenECOMP includes a generic Application Controller (APP-C, sometimes called APPC) that receives commands from OpenECOMP components, such as MSO, DCAE, or the Portal, and uses these commands to manage the life cycle of Services, Resources (virtual applications and Virtual Network Functions), and their components. See the OpenECOMP Application Controller User Guide and the <<DocRef: Application Controller (APP-C) API Guide>>.