Generational mode of Shenandoah is a new experimental feature that has been added to JDK24. The generational mode preserves pause-less operation of traditional Shenandoah, while decreasing CPU time consumed by GC and allowing higher allocation rates without degenerated cycles in the same heap sizes. For many workloads, this allows robust deployment in smaller heap sizes.

This talk provides selected performance comparisons with traditional Shenandoah, Generational ZGC, and G1 GC. It provides selection criteria for helping to determine whether Generational mode of Shenandoah is a good match for your service needs. It also provides best-practice recommendations for how to tune Generational Shenandoah to extract the greatest value for your particular service.