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Abstract: Internet of Things (IoT) applications equip rural producers with decision support tools and automated solutions that boost agribusiness productivity, quality, and profit. However, most poultry farmers still use conventional methods of operation in which human workers carry out all routines for monitoring and controlling their farms at the expense of greater productivity. One of these human activities is manual weighing, which can be replaced by nonintrusive methods such as computational vision applications that estimate live poultry’s weight using video cameras. Since Internet of Things (IoT) devices may have low computing power limiting the ability to process the data locally, they can transfer it to a fog or cloud data center, where they are processed. This article aims to conduct a dependability study of a poultry house automated with a computer vision-based system for estimating poultry weight considering hierarchical models (e.g., Markov chain, reliability block diagram, and closed-form equation) to represent the whole system and obtain steady-state availability and annual downtime. In addition, our purpose is to consider and compare different architectural solutions, such as edge and fog computing-based solutions. The proposed solution verified that a cloud-based application with no redundancy has a downtime of 34.14% and 9.176% hours when considering a hot-standby redundancy strategy in the office node of a cloud solution.

Abstract: During the past years, sending data to the cloud servers was a prominent trend, making the cloud computing paradigm dominate the technology landscape. However, the internet of things (IoT) is becoming a part of our daily environments, and it generates a large volume of data, which is creating uncontrollable delays. For the delay-sensitive and context-aware services, these uncontrollable delays may cause low reliability and availability for applications. To overcome these challenges, computing paradigms are moving from centralized cloud environments to the Edge of the networks. Several new computing paradigms, such as Edge and Fog computing, emerged to support delay-sensitive and context-aware services. By combining edge devices, fog servers, and cloud computing, companies can build a hierarchical IoT infrastructure, using Edge–Fog–Cloud orchestrated architecture to improve IoT environments’ performance, reliability, and availability. This paper presents a comprehensive survey on reliability and availability of Edge, Fog, and Cloud computing architectures. We first introduce and compare some related works about these paradigms and compare them to define the differences between Edge and Fog environments, since there is still some confusion about these terms. We also describe their taxonomy and how they link to each other. Finally, we draw some potential research directions that may help foster research efforts in this area.

Abstract: The Internet is arguably the most important means of communication, as there is no business strategy without the Internet. The Internet Service Provider’s challenge is to ensure the high availability of services to meet customers’ expectations, guaranteeing that they will be available and ready for whatever may be the user’s interests may be. Every time the user tries to access the service or product, and it is unavailable, we have the characterization of the service as unavailability. In this article, we evaluate the ISP’s core availability, identify availability issues in the router component, and study CTMC and RBD models by performing a model validation experiment, executing a steady-state availability, and performing a sensitivity analysis. Hierarchical modeling strategies, (availability models combining reliability block diagrams (RBD) and continuous time Markov chain (CTMC)) were used, indicating the availability of the infrastructure. The critical component of the system was indicated through sensitivity analysis. We performed a model validation technique to demonstrate that the models represent the behavior of the real system. The results showed that the system availability is 0.99941, and the sensitive analysis indicated that if the system administrator optimized the ISP infrastructure in 50%, it would yield a yearly downtime reduction of 3.4 hours.

Abstract: Through the blockchain-as-a-service paradigm, one can provide the infrastructure required to host blockchain-based applications regarding performance and dependability-related attributes. Many works evaluated issues and mitigated them to reach a high throughput or better downtime and availability indexes. However, to the best of our acknowledgment, studies regarding both characteristics are yet to be performed. This paper presents a performance evaluation of a private infrastructure hosting a blockchain-based application. As we monitored the system, we noticed some increase in resource consumption that may be associated with software aging issues on the hyperledger fabric platform or its basic components. Also, the impact of this resource increment on the probability of the system being operational has been evaluated. When consumption issues were considered, one of the transaction types increased the RAM consumption by almost 80% in less than 3 h, reducing the system availability to 98.17%. For scenarios without resource increment issues on the infrastructure, the availability reached 99.35%, with an annual downtime of 56.43 h.