Visually-defined Real-Time Orchestration of IoT Systems

Abstract

In this work, we propose a method for extending Node-RED to allow the automatic decomposition and partitioning of the system towards higher decentralization. We provide a custom firmware for constrained devices to expose their resources, as well as new nodes and modifications in the Node-RED engine that allow automatic orchestration of tasks. The firmware is responsible for low-level management of health and capabilities, as well as executing Mi-croPython scripts on demand. Node-RED then takes advantage of this firmware by (1) providing a device registry allowing devices to announce themselves, (2) generating MicroPython code from dynamic analysis of flow and nodes, and (3) automatically (re-)assigning nodes to devices based on pre-specified properties and priorities. A mechanism to automatically detect abnormal run-time conditions and provide dynamic self-adaptation was also explored. Our solution was tested using synthetic home automation scenarios, where several experiments were conducted with both virtual and physical devices. We then exhaustively measured each scenario to allow further understanding of our proposal and how it impacts the system's resiliency, efficiency, and elasticity. CCS CONCEPTS• Computer systems organization → Embedded and cyberphysical systems; Embedded systems; Distributed architectures; • Software and its engineering → Embedded software; Integrated and visual development environments; • Hardware → System-level fault tolerance.

Evaluation of IoT Self-healing Mechanisms using Fault-Injection in Message Brokers

“…As future improvements to the instrumented MQTT broker, we consider the following: (1) simplify the fault-injection configuration by supporting more native language constructs (e.g., arrow functions) and other configuration abstractions (e.g., leverage visual notations), (2) support wildcard topics as per the MQTT specification, and (3) enable switching configuration at run-time instead of having to specify the configuration file when starting the broker. Regarding the experimental stage, it would be interesting to (1) expand the scenarios with more experiments, including more extensive fault-injection pipelines; (2) replicated the experiments using different datasets; (3) extend the usage of self-healing mechanisms, especially the ones implemented as part of SHEN [16]; and (4) explore decentralized systems and orchestrators [34,39].…”

Empowering Visual Internet-of-Things Mashups with Self-Healing Capabilities

“…We have also identified some limitations, which might be presented as future work, including: (1) resilience to network partitions, as the Redundancy node has no way of finding if there is already a master in the network; (2) most of the nodes still do not support the definition of reasonable margins (e.g., in nodes that deal with timing constrains, a minor delay should be ignored instead of triggering the recover or maintenance action); (3) although its need was identified, no mechanism to synchronize the current system state between different Node-RED instances has been provided, and (4) the capabilities of the DEVICE REGISTRY pattern and device/service discovery are only partial due to the high heterogeneity and lack of standard of IoT systems. Further, current state-of-the-art do not present out-of-the-box solutions for distribution of computational tasks across devices in the heterogeneous IoT system beyond limited (both in scope or supported devices) proofs-of-concept [31], [40], [32], [33], [34], [35], solutions which, if available, would offer foundations for other kinds of fault-tolerance mechanisms beyond the ones presented. Additionally, to be able to validate the correct functioning of our approach, there is the need of a solution that allows one to deliberately provoke failures in the system and report observed behaviours -in cloud computing defined as chaos engineering or fault injection.…”

“…There was also some literature found on the evolution of Node-RED with fault-tolerance considerations. The work by Margarida et al [31] propose a modification to Node-RED that allows the automatic decomposition and partitioning of the system towards higher decentralization, by running a custom firmware on the IoT devices. The system reliability is increase since Node-RED nodes could be automatically assign nodes to devices based on pre-specified properties and priorities, thus when abnormal run-time conditions were observed, the system reconfigured itself (i.e., self-configuration and self-healing).…”

Low-Code Engineering for the Internet of Things

“…Several extensions have been made, such as [210] tackling the reusability issues in cloud-based modeled components, [211] to tackle the heterogeneity and complexity challenges found in the Fog based development. Finally, in [212], the authors presented SHEN to enable self-healing capabilities of applications based on Node-RED.…”