DDMon - A Monitoring Tool for Distributed Deadlock Detection

Learn about DDMon, a proof-of-concept monitoring tool designed for distributed black-box deadlock detection in Erlang and Elixir systems based on generic servers (gen_server) in this 18-minute conference presentation from Erlang 2025. Discover how DDMon functions as a drop-in replacement for the gen_server module, requiring minimal user intervention while deploying invisible monitors alongside each gen_server process. Explore the tool's distributed architecture where monitors communicate with each other to detect deadlocks without introducing centralized bottlenecks. Understand DDMon's precision in deadlock detection, as it reports the exact set of deadlocked processes without false positives or false negatives, ensuring that only real deadlocks are reported and all deadlocked processes are identified. Gain insights into the implementation details and companion artifact of research accepted at OOPSLA 2025 titled "Correct Black-Box Monitors for Distributed Deadlock Detection: Formalisation and Implementation." The presentation was delivered by Radosław Jan Rowicki from the Technical University of Denmark at the Erlang 2025 workshop.