#AZUL OPENJDK SHENANDOAH FULL#

Non-generational Shenandoah garbage collection already provides this ideal GC behavior for latency-sensitive Java applications. Garbage collectors with concurrent compaction are capable of completely blending GC pause times into the single-digit millisecond range of other common JVM pauses, while also leaving mutator execution speed nearly unfettered.

#AZUL OPENJDK SHENANDOAH FULL#

Successful runs reduce or eliminate the number for allocation stalls and the need for full or degenerated collections. Operational envelopes (i.e., combinations of allocation rate, heap occupancy, and pause time target) for HyperAlloc, Extremem, and similar workloads are compared to non-generational Shenandoah. Generational Shenandoah is benchmarked against non-generational Shenandoah using SPECjbb2015, HyperAlloc, Extremem and Dacapo. In the initial release, ergonomic heuristics may not provide optimal behavior on all workloads. If longer pauses can be tolerated, other collectors such as the Parallel collector may still provide superior throughput on certain platforms. It is not a goal to maximize mutator throughput. However, Generational Shenandoah will fare much closer to current generational stop-the-world GCs in this respect than non-generational Shenandoah. Generational Shenandoah can only approximate but never match the efficiency tactics of stop-the-world GCs given its mandates to keep pause times much lower and to avoid stop-the-world compactions entirely.

If longer pauses can be tolerated, other collectors such as G1 may still provide more energy-efficient behavior. It is not a goal to improve CPU and power usage compared to traditional stop-the-world GCs. Nevertheless, we expect the majority of use cases to benefit from generational collection.

The generational system will dynamically adapt to approximate a non-generational system as needed but, for some workloads, starting out and remaining with a single generation may still be a superior option. It is not a goal to improve performance for every conceivable workload. It is not a goal to replace non-generational Shenandoah, which will continue to be the default mode of operation with no regressions in its performance or functionality. Initially support 圆4 and AArch64, with support for other instruction sets added as this experimental mode progresses to readiness as the default option. Reduce the sustained memory footprint without sacrificing the low GC pauses.ĭecrease the risk of incurring degenerated and full collections during allocation spikes.Ĭontinue to support compressed object pointers. Other goals are set relative to non-generational Shenandoah: The main goal is to provide an experimental generational mode, without breaking non-generational Shenandoah, with the intent to make it the default in a future release.

Enhance the Shenandoah garbage collector with experimental generational collection capabilities to improve sustainable throughput, load-spike resilience, and memory utilization.

Azul openjdk shenandoah