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- Proposed name for the project:
ONAP Optimization Framework (ONAP-OF) - Proposed name for the repository: optf
Subrepositories:
optf/pas has -- placement homing and allocation service
optf/cmso -- change management scheduling service
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ONAP needs core platform optimization services such as VNF placement and resource allocation (homing), resource allocation, and change management scheduling to function in any multi-site, multi-VIM, and multi-service environment. It could also benefit from a framework which promotes the reuse of software tools and algorithms to allow users to construct new optimization services and to extend/enhance existing platform optimization services.
This project currently provides the following two core platform optimization services, which are built to be service independent, policy driven, and extensible along with an optimization framework to enhance these or creating new services.
a) PAS HAS (Placement Homing and Allocation Service) optimizer: a policy driven service placement and resource allocation service to allow deployment of services and VNFs on a multi-site, multi-VIM infrastructure. This service performs function similar to classic OS schedulers or OpenStack scheduler. The role of the PAS HAS is to select which cloud and which sites the elements of a service should be placed in, while respecting service constraints (latency, availability of specific platform features) as well as platform needs (cost).
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The set of platform optimization services will grow over time as the ONAP platform needs arise, and the optimization framework is envisioned to handle this as effectively as possible, with minimal or little new code development for creating new services. The optimization service design framework (OSDF), which can be used to build new optimization applications for users of ONAP, as well as to build new platform optimization services or extend the existing platform services through plugins. To demonstrate its capabilities, OSDF has been used to entirely build the change management scheduling optimizer (CMSO) as well as to build VNF license optimization and connectivity optimization plugins for the placement homing and allocation service (PASHAS). The OSDF is intended to allow future applications such as energy optimization in networks, optimal route selection, and radio access network (RAN) runtime performance optimization.
We will describe the current platform optimization services and optimization framework with their architectural fit one by one.
PASHAS: policy driven service placement homing and resource allocation on a multi-site, multi-VIM infrastructure. Placement Homing/placement and allocation of resources is one of the fundamental requirements of provisioning a service over the cloud (or even non-cloud) infrastructure. PAS HAS allows designers of services/VNFs to specify their service-specific placement requirements using policy constraints (e.g., geo-redundancy requirements for disaster recovery) and objective functions (e.g., minimize latency) linked to the service model. Then, at service deployment time, PAS HAS collects information from AAI, DCAE, and other sources to determine a placement solution that meets service constraints while considering both the service objective function and the service provider preferences (e.g., cost) and constraints (e.g., available of capacity). Once a placement decision is made, a resource allocation (reservation) decision can be registered in AAI or with the resource manager for the resource if necessary.
PAS HAS can home a request either to a cloud site where new virtual resources are to be created or to an existing service instance. When the services deployed become more complex (e.g., multiple VNFs with different constraints for individual VNFs and the combinations of VNFs) and the cloud infrastructure is large (e.g., dozens or more possible sites), such capability is essential for managing the services and the infrastructure.
PAS HAS will be designed to be used as a building block for both initial deployment, as well as runtime redeployment due to failures or runtime-capacity increase (scale-out). It will be designed to be usable for all platform placement functions, including placements of VMs, containers (e.g., for DCAE micro-services), or VNF specific resources. A plugin model will be provided to allow placements of additional resource types such as licenses, VNF resources. Plugin models will also allow extension by adding new constraint types, optimizer types, and objective functions.
Architecture alignment:
- SO invokes PAS HAS to get a placement and license allocation decision when deploying a new service, or when it is called to redeploy a service upon site failure, or upon increasing the capacity of an already existing service. This is particularly useful in multi-site or multi-VIM environments.
- VF-C/App-C may need to invoke PAS HAS to get a placement decision if an existing VNF must be rebuilt due to failure or increase in capacity.
- OOM may need to invoke PAS HAS to get a placement decision when deploying ONAP components e.g., to get a DCAE micro-service to be placed in proximity to the VNF it is monitoring.
- Policy will need to support PAS HAS by storing placement policies and associating them with service models
- PAS HAS uses information stored in AAI (e.g., available inventory), DCAE (e.g., performance, utilization), SDN-C and other ONAP components to make placement decisions.
- Multi-VIM: PAS HAS allows placement constraints to be specified that drives workloads to different cloud providers when appropriate (e.g., VNF requires some specific cloud platform) or desired (e.g., VNF requires certain level of reliability or performance that only some cloud providers can meet).
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Sastry Isukapalli sastry@research.att.com AT&T
Ankitkumar Patel ankit@research.att.com AT&T
Matti Hiltunen hiltunen@atthiltunen@research.att.com AT&T
Shankar Narayanan snarayanan@research.att.com AT&T
Joe D'Andrea jdandrea@research.att.com AT&T
Maopeng Zhang zhang.maopeng1@zte.com.cn ZTE
Alexander Vul alex.vul@intel.com Intel
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