Availability Evaluation of the Nextcloud Service Hosted in a Private Cloud
Abstract
Cloud computing has become a strategic solution to address the growing demands for connectivity and flexibility in accessing computational resources. Consequently, it is necessary to identify the components with the greatest impact on the system and implement redundancies efficiently, ensuring high availability, optimal performance, and cost reduction. This paper proposes the use of Reliability Block Diagrams (RBD) to assess the dependability of a private cloud environment, focusing on the metrics of availability, uptime, and downtime. The case study aims to identify and analyze critical components for system availability, applying redundancies to these components to reduce downtime and increase uptime. The results demonstrated that the application of redundancies can lead to an increase of up to 25% in system availability.
Keywords:
Cloud Computing, Availability, Stochastic Petri nets, Reliability Block Diagrams
References
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Clemente, D., Pereira, P., Dantas, J., and Maciel, P. (2022). Availability evaluation of system service hosted in private cloud computing through hierarchical modeling process. The Journal of Supercomputing, 78(7):9985–10024.
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Faraji Shoyari, M., Ataie, E., Entezari-Maleki, R., and Movaghar, A. (2021). Availability modeling in redundant openstack private clouds. Software: Practice and Experience, 51(6):1218–1241.
Figueirêdo, J., Maciel, P., Callou, G., Tavares, E., Sousa, E., and Silva, B. (2011). Estimating reliability importance and total cost of acquisition for data center power infrastructures. In 2011 IEEE international conference on systems, man, and cybernetics, pages 421–426. IEEE.
Haas, P. J. (2006). Stochastic petri nets: Modelling, stability, simulation. Springer Science & Business Media.
Johnson, B. W. (1988). Design & analysis of fault tolerant digital systems. Addison-Wesley Longman Publishing Co., Inc.
Maciel, P., Dantas, J., Melo, C., Pereira, P., Oliveira, F., Araujo, J., and Matos, R. (2022). A survey on reliability and availability modeling of edge, fog, and cloud computing. Journal of Reliable Intelligent Environments, pages 1–19.
Maciel, P., Trivedi, K., and Kim, D. (2010). Dependability modeling in: Performance and dependability in service computing: Concepts, techniques and research directions. Hershey: IGI Global, Pennsylvania, USA, 13:1380.
Martins Maciel, P. R. (2016). Modeling availability impact in cloud computing. Principles of Performance and Reliability Modeling and Evaluation: Essays in Honor of Kishor Trivedi on his 70th Birthday, pages 287–320.
Murata, T. (1989). Petri nets: Properties, analysis and applications. Proceedings of the IEEE, 77(4):541–580.
Pereira, P., Araujo, J., Melo, C., Santos, V., and Maciel, P. (2021). Analytical models for availability evaluation of edge and fog computing nodes. The Journal of Supercomputing, 77:9905–9933.
Pereira, P., Melo, C., Araujo, J., Dantas, J., Santos, V., and Maciel, P. (2022). Availability model for edge-fog-cloud continuum: an evaluation of an end-to-end infrastructure of intelligent traffic management service. The Journal of Supercomputing, pages 1–28.
Silva, A. and Callou, G. (2025). Models for availability evaluation of file servers in private clouds. Computing, 107(1):1–27.
Silva, B., Matos, R., Callou, G., Figueiredo, J., Oliveira, D., Ferreira, J., Dantas, J., Lobo Júnior, A., Alves, V., and Maciel, P. (2015). Mercury: An integrated environment for performance and dependability evaluation of general systems.
Xie, M., Dai, Y.-S., and Poh, K.-L. (2004). Computing system reliability: models and analysis. Springer Science & Business Media.
Asio, J. M. R., Gadia, E., Abarintos, E., Paguio, D., and Balce, M. (2021). Internet connection and learning device availability of college students: Basis for institutionalizing flexible learning in the new normal. Studies in Humanities and Education, 2(1):56–69.
Bauer, E. and Adams, R. (2012). Reliability and availability of cloud computing. John Wiley & Sons.
Callou, G. and Vieira, M. (2024). Availability and performance analysis of cloud services. In Proceedings of the 13th Latin-American Symposium on Dependable and Secure Computing, LADC ’24, page 262–271, New York, NY, USA. Association for Computing Machinery.
Clemente, D., Pereira, P., Dantas, J., and Maciel, P. (2022). Availability evaluation of system service hosted in private cloud computing through hierarchical modeling process. The Journal of Supercomputing, 78(7):9985–10024.
Cloud, H. (2011). The nist definition of cloud computing. National institute of science and technology, special publication, 800(2011):145.
Faraji Shoyari, M., Ataie, E., Entezari-Maleki, R., and Movaghar, A. (2021). Availability modeling in redundant openstack private clouds. Software: Practice and Experience, 51(6):1218–1241.
Figueirêdo, J., Maciel, P., Callou, G., Tavares, E., Sousa, E., and Silva, B. (2011). Estimating reliability importance and total cost of acquisition for data center power infrastructures. In 2011 IEEE international conference on systems, man, and cybernetics, pages 421–426. IEEE.
Haas, P. J. (2006). Stochastic petri nets: Modelling, stability, simulation. Springer Science & Business Media.
Johnson, B. W. (1988). Design & analysis of fault tolerant digital systems. Addison-Wesley Longman Publishing Co., Inc.
Maciel, P., Dantas, J., Melo, C., Pereira, P., Oliveira, F., Araujo, J., and Matos, R. (2022). A survey on reliability and availability modeling of edge, fog, and cloud computing. Journal of Reliable Intelligent Environments, pages 1–19.
Maciel, P., Trivedi, K., and Kim, D. (2010). Dependability modeling in: Performance and dependability in service computing: Concepts, techniques and research directions. Hershey: IGI Global, Pennsylvania, USA, 13:1380.
Martins Maciel, P. R. (2016). Modeling availability impact in cloud computing. Principles of Performance and Reliability Modeling and Evaluation: Essays in Honor of Kishor Trivedi on his 70th Birthday, pages 287–320.
Murata, T. (1989). Petri nets: Properties, analysis and applications. Proceedings of the IEEE, 77(4):541–580.
Pereira, P., Araujo, J., Melo, C., Santos, V., and Maciel, P. (2021). Analytical models for availability evaluation of edge and fog computing nodes. The Journal of Supercomputing, 77:9905–9933.
Pereira, P., Melo, C., Araujo, J., Dantas, J., Santos, V., and Maciel, P. (2022). Availability model for edge-fog-cloud continuum: an evaluation of an end-to-end infrastructure of intelligent traffic management service. The Journal of Supercomputing, pages 1–28.
Silva, A. and Callou, G. (2025). Models for availability evaluation of file servers in private clouds. Computing, 107(1):1–27.
Silva, B., Matos, R., Callou, G., Figueiredo, J., Oliveira, D., Ferreira, J., Dantas, J., Lobo Júnior, A., Alves, V., and Maciel, P. (2015). Mercury: An integrated environment for performance and dependability evaluation of general systems.
Xie, M., Dai, Y.-S., and Poh, K.-L. (2004). Computing system reliability: models and analysis. Springer Science & Business Media.
Published
2025-05-19
How to Cite
LEONARDO, Wenderson de Souza; CALLOU, Gustavo.
Availability Evaluation of the Nextcloud Service Hosted in a Private Cloud. In: FAULT TOLERANCE WORKSHOP (WTF), 25. , 2025, Natal/RN.
Anais [...].
Porto Alegre: Sociedade Brasileira de Computação,
2025
.
p. 85-98.
ISSN 2595-2684.
DOI: https://doi.org/10.5753/wtf.2025.8838.
