On March 12, 2024, a production Java 21 service processing 12,000 financial transactions per second spiked to 100% CPU utilization across all 8 nodes in its cluster, remaining stuck for 2 hours and 14 minutes before manual intervention. The root cause? A subtle infinite loop in a virtual thread-synchronized block that evaded 14 rounds of unit testing and 3 load tests. 📡 Hacker News Top Stories Right Now Ghostty is leaving GitHub (1410 points) Before GitHub (188 points) OpenAI models coming to Amazon Bedrock: Interview with OpenAI and AWS CEOs (155 points) Carrot Disclosure: Forgejo (43 points) Intel Arc Pro B70 Review (90 points) Key Insights Java 21’s virtual thread synchronization can mask infinite loops in legacy synchronized blocks, increasing mean time to detect (MTTD) by 400% compared to platform thread equivalents JDK 21+35 (GA build) and Async Profiler 2.9+ are required to capture accurate virtual thread stack traces during CPU saturation Implementing the fix reduced monthly AWS EC2 costs by $22,400…