Evaluating Java Virtual Threads for Concurrent Spring Boot and Helidon Services

Virtual Threads were introduced to address the scalability limitations of traditional platform threads in large- scale, highly concurrent, server-side Java applications. By reducing the overhead of thread creation, scheduling, and management, Virtual Threads enable an efficient thread-per- request programming model that was previously impractical at scale. Contemporary Java frameworks, including Spring Boot and Helidon, support this modern model of concurrency. However, the combined influence of framework architecture and thread type on application behavior under high concurrency remains insufficiently explored.Our research presents an evaluation of Java Virtual Threads in Spring Boot and Helidon frameworks, compared against platform threads within the same frameworks. An HTTP-based service benchmark is implemented across all framework-thread combinations, focusing on framework and threading models as the factors of interest. Each configuration is subjected to progressively increasing client concurrency, collecting typical performance-relevant metrics, such as throughput, latency, and resource utilization.The results demonstrate that the Virtual Threads influence application behavior under load and affect scalability and resource efficiency, revealing framework-specific performance patterns in high-concurrency Java services. These findings provide a clearer understanding of Virtual Thread behavior in Java frameworks and offer insights for designing robust, high-throughput Java services and making informed concurrency and framework selection decisions. (Abstract)Virtual Threads, Java Concurrency,