This article explores JDK 21's virtual threads, comparing their performance with Open Liberty's thread pool and highlighting key findings and performance issues.

InfoQ is a leading online platform for software developers, architects, and technical leaders, providing news, articles, presentations, and interviews on a wide range of topics, including agile practices, DevOps, microservices, and emerging technologies. With a focus on quality content and expert insights, InfoQ helps professionals stay informed about the latest trends, best practices, and industry developments. Developers can learn from real-world experiences, gain  knowledge, and connect with peers in the global software community through InfoQ's diverse and engaging content.

InfoQ

Java Virtual Threads, introduced in JDK 21, offer a new lightweight, scalable approach to concurrency. However, they do not present clear advantages over Open Liberty's existing autonomic thread pool for typical cloud-native Java workloads. Performance evaluations revealed that while virtual threads ramp up faster, their CPU throughput is generally lower for CPU-intensive tasks. Memory footprint benefits are inconsistent and can be outweighed by other JVM memory usages. Some unexpected performance issues due to interactions with the Linux kernel and ForkJoinPool were also observed.

Java Virtual Threads: A Case Study