RT journal article T1 Detecting security attacks in cyber-physical systems: a comparison of Mule and WSO2 intelligent IoT architectures A1 Roldán-Gómez, José A1 Boubeta Puig, Juan A1 Pachacama-Castillo, Gabriela A1 Ortiz Bellot, Guadalupe A1 Martínez, José Luis A2 Ingeniería Informática K1 Internet of things K1 Complex event processing K1 Machine learning K1 Pattern detection K1 Security attack AB The Internet of Things (IoT) paradigm keeps growing, and many different IoTdevices, such as smartphones and smart appliances, are extensively used in smartindustries and smart cities. The benefits of this paradigm are obvious, but these IoTenvironments have brought with them new challenges, such as detecting andcombating cybersecurity attacks against cyber-physical systems. This paper addressesthe real-time detection of security attacks in these IoT systems through the combinedused of Machine Learning (ML) techniques and Complex Event Processing (CEP).In this regard, in the past we proposed an intelligent architecture that integrates MLwith CEP, and which permits the definition of event patterns for the real-timedetection of not only specific IoT security attacks, but also novel attacks that have notpreviously been defined. Our current concern, and the main objective of this paper,is to ensure that the architecture is not necessarily linked to specific vendortechnologies and that it can be implemented with other vendor technologies whilemaintaining its correct functionality. We also set out to evaluate and compare theperformance and benefits of alternative implementations. This is why the proposedarchitecture has been implemented by using technologies from different vendors:firstly, the Mule Enterprise Service Bus (ESB) together with the Esper CEP engine;and secondly, the WSO2 ESB with the Siddhi CEP engine. Both implementationshave been tested in terms of performance and stress, and they are compared anddiscussed in this paper. The results obtained demonstrate that both implementationsare suitable and effective, but also that there are notable differences betweenthem: the Mule-based architecture is faster when the architecture makes use of twomessage broker topics and compares different types of events, while the WSO2-basedone is faster when there is a single topic and one event type, and the system has aheavy workload. PB PEERJ INC SN 2376-5992 YR 2021 FD 2021-11 LK http://hdl.handle.net/10498/26122 UL http://hdl.handle.net/10498/26122 LA eng NO This work was supported by the Spanish Ministry of Science, Innovation and Universities and the European Union FEDER Funds [grant numbers FPU 17/02007, RTI2018-093608-B-C33, RTI2018-098156-B-C52 and RED2018-102654-T] . This work was also supported by the JCCM [grant number SB-PLY/17/180501/000353] and the Research Plan from the University of Cadiz and Grupo Energetico de Puerto Real S.A. under project GANGES [grant number IRTP03' UCA] . The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. DS Repositorio Institucional de la Universidad de Cádiz RD 13-nov-2026