Virtual Thread memory leak in Java 19+ causing hangs in high-concurrency apps

Using virtual threads heavily in Java 19, my application gradually consumes native memory and freezes, even though thread counts are low. What’s happening?

On Java 19 (fixed by 19.0.2 and Java 20), there were known memory leaks related to virtual threads—especially when many short-lived threads were created rapidly or under debugging conditions. These leaks can prevent GC or cause native memory exhaustion, hanging the application ([turn0reddit15]). 🛠️ How to Fix • Upgrade to Java 20 or higher (the issue is resolved in these versions). • If upgrading isn’t feasible, reduce creation rate of virtual threads and group work in batches or reuse. • Monitor native memory usage using tools like JFR or profilers. • For long-running thread-heavy workloads, consider using platform threads or structured concurrency patterns.