Execution Fabric
A. Workflow
The execution fabric mainly consists of a workflow engine that executes the workflow steps generated by the life cycle manager from a service model. The workflow engine is a simple engine that executes the workflow steps in the correct order. It is triggered off events published to the messaging bus.
GIN has also incorporated an opensource cloud native workflow engine called Argo to execute the workflow steps in a container. Although we believe, for most instances the Argo workflow or the simple workflow engine will suffice, we can also plugin the open source Camunda workflow engine if a more robust and distributed workflow engine is preferred. In all cases the workflows will be automatically generated from the model.
B. Policy
The policy engine is a simple engine that executes the policy defined in a tosca model. It is also triggered off events published to the messaging bus. The GIN allows models to be built where the policies defined in the model can be translated to the policies which can be run by the Drools policy engine that comes with ONAP. In addition, GIN can also leverage the Kapacitor processor in the TICK stack to handle policies defined in terms of its alerts and handlers.
C. Analytics
The platform has adopted the TICK (Telegraf, InfluxDb, Chronograf, Kapacitor) stack – a collection of open source components that combine to deliver a platform for easily storing, visualizing and monitoring time series data such as metrics and events. The platform is flexible in allowing the models to plug in other opensource analytics components like Prometheus and Grafana to be substituted in place of some of the original TICK components.