OF@TEIN+ playground launched to serve as SDN-enabled multi-site clouds for miniaturized academic experiments is a miniaturized, software-defined playground with hyper-converged box-style resources. It is an overlay-interconnected, multi-site playground over heterogeneous (3 ∼7 inter-connected) underlay networks. Built for cloud-native edge boxes, OF@TEIN+ playground leverages “SmartX Playground Tower,” a logical space in centralized location meant to automatically build, operate, and utilize OF@TEIN+ playground. OF@TEIN+ maintain multiple types of distributed physical and virtual resources that are dynamically provided to the developers to learn operational and development issues and perform various experiments.
In the given environment, we placed cloud-native edge boxes termed “SmartX Micro-Box” aka Micro-Box, distributed at multi-site edge locations of OF@TEIN+ playground. These Micro-Boxes are commodity server-based hyper-converged resources (compute /storage/networking) to allow experiments (Cloud/Software-defined networking/Network Function Virtualization) overOF@TEIN+playground.
Supported by cloud-native (containerized) functionalities,Micro-Box is prepared as Kubernetes-orchestrated workers with SDN-coordinated special connectivity to other Micro-Boxes. The tenant awareness of deployed containerized application provides isolation. For network connectivity, we use three network interfaces as shown in Figure ,Micro-Box is configured with two public IPs, configured as control interface and data interface.
In terms of visibility measurements among multiple distributed sites, Micro-Boxes are configured in mesh-style networking,where visibility collection is reported to the centralized Visibility Center at the SmartX Playground Tower. As depicted in Figure , the applications running in the Micro-Box are termed as “Functionalities,” whereas the corresponding applications at the Tower Centers are termed as “Companion functionalities.” The software version in the Micro-Box is named as “$ (Dollar)” and the “Core functionalities” consist of software functionality that manages the Micro-Box operations such as OS, kernel, Kubernetes, etc. “Basic functionalities” are additional development at the baremetal and constitutes monitoring of connection status/health with connected Micro-Boxes in the playground, ensuring collection consistency and service reliability. The “Application functionalities” consist of applications in the form factor of containers orchestrated through Kubernetes. Maintaining persistent visibility is crucial for the effective operation of OF@TEIN+ playground to ensure reliable operations with timely knowledge of issues concerning playground.
Furthermore, to ensure reliable and uninterrupted operation, we collected regular connection status of Micro-Box with the Visibility Center called “liveliness status of Micro-Box,” as well as connection status with other Micro-Boxes called “interconnection liveliness.” Reporting is action taken byMicro-box to an assigned task (eg, sending collected measurements to the center, whereas response is the action taken at Visibility Center to an event generated fromMicro-box). Measurements are transferred through a shared messaging interface ensuring reliable communication and resistance against losses. To ensure persistent execution of functionalities, Agents monitors and starts stopped services. Box-Agent asynchronously communicates with Center-Agent with status messages. Persistent storage stores data for real-time and temporal analysis.