article published yes Marek Chalupa author 87e34708-d6c6-11ec-9f5b-9391e7be2463 Fabian Mühlböck author 6395C5F6-89DF-11E9-9C97-6BDFE56974250000-0003-1548-0177 Stefanie Muroya Lei author a376de31-8972-11ed-ae7b-d0251c13c8ff Thomas A Henzinger author 40876CD8-F248-11E8-B48F-1D18A9856A870000-0002-2985-7724 ToHe department Vigilant Algorithmic Monitoring of Software project As the complexity and criticality of software increase every year, so does the importance of runtime monitoring. Third-party and best-effort monitoring are especially valuable, yet under-explored areas of runtime monitoring. In this context, third-party monitoring means monitoring with a limited knowledge of the monitored software (as it has been developed by a third party). Best-effort monitoring keeps pace with the monitored software at the cost of possibly imprecise verdicts when keeping up with the monitored software would not be feasible. Most existing monitoring frameworks do not support the combination of third-party and best-effort monitoring because they either require the full access to the monitored code or the ability to process all observable events, or both. We present a middleware framework, Vamos, for the runtime monitoring of software. Vamos is explicitly designed to support third-party and best-effort scenarios. The design goals of Vamos are (i) efficiency (tracing events with low overhead), (ii) flexibility (the ability to monitor a variety of different event channels, and to connect to a wide range of monitors), and (iii) ease-of-use. To achieve its goals, Vamos combines aspects of event broker and event recognition systems with aspects of stream processing systems. We implemented a prototype toolchain for Vamos and conducted a set of experiments demonstrating the usability of the scheme. The results indicate that Vamos enables writing useful yet efficient monitors, and simplifies key aspects of setting up a monitoring system from scratch. https://research-explorer.ista.ac.at/download/18169/18831/2024_ScienceCompProg_Chalupa.pdf application/pdfno https://creativecommons.org/licenses/by/4.0/ Elsevier2025 eng 0167-6423 00132785260000110.1016/j.scico.2024.103212 2402 https://research-explorer.ista.ac.at/record/12856 Chalupa, Marek, et al. “VAMOS: Middleware for Best-Effort Third-Party Monitoring.” <i>Science of Computer Programming</i>, vol. 240, no. 2, 103212, Elsevier, 2025, doi:<a href="https://doi.org/10.1016/j.scico.2024.103212">10.1016/j.scico.2024.103212</a>. Chalupa M, Mühlböck F, Muroya Lei S, Henzinger TA. VAMOS: Middleware for best-effort third-party monitoring. <i>Science of Computer Programming</i>. 2025;240(2). doi:<a href="https://doi.org/10.1016/j.scico.2024.103212">10.1016/j.scico.2024.103212</a> Chalupa, M., Mühlböck, F., Muroya Lei, S., &#38; Henzinger, T. A. (2025). VAMOS: Middleware for best-effort third-party monitoring. <i>Science of Computer Programming</i>. Elsevier. <a href="https://doi.org/10.1016/j.scico.2024.103212">https://doi.org/10.1016/j.scico.2024.103212</a> M. Chalupa, F. Mühlböck, S. Muroya Lei, and T. A. Henzinger, “VAMOS: Middleware for best-effort third-party monitoring,” <i>Science of Computer Programming</i>, vol. 240, no. 2. Elsevier, 2025. M. Chalupa, F. Mühlböck, S. Muroya Lei, T.A. Henzinger, Science of Computer Programming 240 (2025). Chalupa M, Mühlböck F, Muroya Lei S, Henzinger TA. 2025. VAMOS: Middleware for best-effort third-party monitoring. Science of Computer Programming. 240(2), 103212. Chalupa, Marek, Fabian Mühlböck, Stefanie Muroya Lei, and Thomas A Henzinger. “VAMOS: Middleware for Best-Effort Third-Party Monitoring.” <i>Science of Computer Programming</i>. Elsevier, 2025. <a href="https://doi.org/10.1016/j.scico.2024.103212">https://doi.org/10.1016/j.scico.2024.103212</a>. 181692024-10-06T22:01:10Z2025-09-09T12:25:29Z