# Active Monitoring with RTLola: A Specification-Guided Scheduling Approach

arXiv: https://arxiv.org/abs/2507.20615 · HTML: https://mlsanity.com/paper/2507.20615/

## Key facts

- Cited by 1 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 28 Jul 2025.

## Built on by (most cited first, 1 of 1)

- [FairMon: A Tool for Monitoring and Visualizing Algorithmic Fairness](https://mlsanity.com/paper/2609.26123/) (2026)

## Abstract (arXiv)

Stream-based monitoring is a well-established runtime verification approach which relates input streams, representing sensor readings from the monitored system, with output streams that capture filtered or aggregated results. In such approaches, the monitor is a passive external component that continuously receives sensor data from the system under observation. This setup assumes that the system dictates what data is sent and when, regardless of the monitor's current needs. However, in many applications -- particularly in resource-constrained environments like autonomous aircraft, where energy, size, or weight are limited -- this can lead to inefficient use of communication resources. We propose making the monitor an active component that decides, based on its current internal state, which sensors to query and how often. This behavior is driven by scheduling annotations in the specification, which guide the dynamic allocation of bandwidth towards the most relevant data, thereby improving monitoring efficiency. We demonstrate our approach using the stream-based specification language RTLola and assess the performance by monitoring a specification from the aerospace domain. With equal bandwidth usage, our approach detects specification violations significantly sooner than monitors sampling all inputs at a fixed frequency.