Oracle Helidon taps virtual threads for ‘pure performance’

Oracle’s Helidon, a set of Java libraries for developing cloud-native microservices, is set to improve performance via virtual threads with the planned 4.00 release.

Currently in an alpha state of development, Helidon 4.0.0 introduces Nima, a web server based on virtual threads, which are lightweight JVM-managed threads that can improve scalability. Virtual threads, introduced in this week’s Java Development Kit (JDK) 20 and last September’s JDK 19, are also intended to significantly reduce the effort required to write and maintain high-performance concurrent applications.

Developers can access the alpha version of Helidon 4.0.0 via GitHub; Instructions for getting started with Helidon can be found at helidon.io. Nima is compatible with MicroProfile 5.0 and replaces the Netty NIO client-server framework that previously powered the Helidon web core. Nima and virtual threads, which have been described as offering “pure performance with no cheating”, are intended to provide low overhead concurrent server while maintaining a blocking thread model. This facilitates reactive programming.

Helidon 4.0.0, as a major release, also has some backward-incompatible API changes, according to the recent release notes. Java 19 or higher is required to use the alpha version 5 of Helidon. The project will support Java 20 soon and Java 21 by the end of the year.

Helidon supports two programming models: Helidon ME, which is a microservices implementation of MicroProfile with a declarative style and dependency injection, and Helidon SE, which is a microframework model with a functional-style API and a small footprint. The latest production version of Helidon is version 3.2.0.