Optimization Framework: Homing and Allocation
OOF-HAS is an policy-driven placement optimizing service (or homing service) that allows ONAP to deploy services automatically across multiple sites and multiple clouds. It enables placement based on a wide variety of policy constraints including capacity, location, platform capabilities, and other service specific constraints.
HAS is a distributed resource broker that enables automated policy-driven optimized placement of services on a global heterogeneous platform using ONAP. Given a set of service components (based on SO decomposition flows) and requirements for placing these components (driven by policies), HAS finds optimal resources (cloud regions or existing service instances) to home these service components such that it meets all the service requirements. HAS is architected as an extensible homing service that can accommodate a growing set of homing objectives, policy constraints, data sources and placement algorithms. It is also service-agnostic by design and can easily onboard new services with minimal effort. Therefore, HAS naturally extends to a general policy-driven optimizing placement platform for wider range of services, e.g., DCAE micro-services, ECOMP control loops, server capacity, etc. Finally, HAS provides an traceable mechanism for what-if analysis which is critical for ease of understanding a homing recommendation and resolving infeasibility scenarios.
OF-HAS is the implementation of the ONAP Homing Service. The formal project name in ONAP is OF-HAS. The informal name for the project is Conductor (inherited from the seed-code), which is interchangeably used through the project.
Given the description of what needs to be deployed (demands) and the placement requirements (constraints), Conductor determines placement candidates that meet all constraints while optimizing the resource usage of the AIC infrastructure. A customer request may be satisfied by deploying new VMs in AIC (AIC inventory) or by using existing service instances with enough remaining capacity (service inventory).
From a canonical standpoint, Conductor is known as a homing service, in the same way OpenStack Heat is an orchestration service, or Nova is a compute service.