# Emerging Industrial Internet of Things Open-Source Platforms and Applications in Diverse Sectors
## 4 Open-Source Edge IoT platforms
### Thingsboard IoT Edge Framework  
ThingsBoard serves as a comprehensive platform for collecting, analyzing, visualizing, and overseeing data, supporting key IoT protocols including CoAP, OPC-UA, MQTT, and HTTP. It offers flexible deployment options, either cloud-based or on-premises [62, 63]. The platform facilitates the creation of workflows triggered by various events, including life cycle changes, REST API activities, and RPC requests [62]. Additionally, ThingsBoard Edge offers an edge computing solution, allowing for data-processing and management directly at the data's origin. This edge solution can integrate with various ThingsBoard cloud \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Database** & **Functionality** & **Flexibility** & **Pros** & **Cons** \\ \hline MySQL [51] & ACID-compliant, wide range of data types, & Deployable on various platforms & Cost-effective, scalable & Limited advanced features \\ \hline PostgreSQL [52] & Wide range of data types, advanced features & Integrates with multiple languages & Powerful, flexible & Complex for large-scale deployments \\ \hline MongoDB [53] & Dynamic queries, JSON-like documents & Suitable for various applications & Highly available, flexible modeling & Requires strong data consistency \\ \hline Redis [54, 55] & In-memory key-value store, supports transactions & Used as database, cache, message broker & High performance, low latency & Not for large data storage \\ \hline Apache Cassandra [56] & Distributed database, supports wide column & Suitable for real-time analytics, e-commerce & High availability, fault tolerance & Steep learning curve \\ \hline MariaDB [57] & Compatible with MySQL, various query types & Deployable on-premise, in cloud & Excellent security features & Compatibility issues with MySQL-specific apps \\ \hline InfluxDB [58] & Time-series data, high-precision timestamps & Monitoring, analytics, IoT & Optimized for time-series data & Limited compared to other databases \\ \hline Elasticsearch [59] & Full-heat search, real-time analytics & Search, analytics, logging, monitoring & Real-time & Resource-intensive for real-time analytics \\ \hline Apache CouchDB [60] & Document-oriented format, RESTful HTTP API & Web, mobile applications, CMS & Flexible, scalable & Steeper learning curve \\ \hline Neo4j [61] & Graph data model, Cypher query language & Recommendation engines, network management & Performance for graph data & Limited compared to traditional databases \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Comparison of popular open-source databases. services tailored to specific user needs, but it is limited to single-tenant use, prohibiting multi-tenant applications and device-sharing across tenants. Moreover, ThingsBoard (as shown in Figure 3) boasts a robust, scalable, and fault-resistant infrastructure alongside a secure environment for seamless device management. It can process and standardize input from devices, trigger alarms for various telemetry issues, and support customizable rules for targeted functionalities. It is also capable of managing millions of devices simultaneously without a single point of failure, thanks to its clustered architecture in which each node is independent. Moreover, it offers multi-tenant capabilities beyond the core cluster setup and provides a rich selection of over thirty customizable dashboard widgets for enhanced user interaction. Figure 4 illustrates the support for federated connectivity protocols for data ingestion in the Thingsboard Edge IoT technology. This technology requires an edge platform that is compatible with a wide range of devices and hardware vendors. There are many different standards employed in Internet of Things (IoT) applications, including a large number of accepted ones and a long list of proprietary ones used in both custom-made and pre-made products. Thingsboard edge/IoT platforms are designed to accommodate a broad range of IoT devices with a variety of protocols for data ingestion.