In this blog post, we will delve into the concepts of concurrent evacuation start and concurrent evacuation stats in the Shenandoah Garbage Collector (GC) for Java applications. These features play a crucial role in optimizing garbage collection and improving application performance.
Table of Contents
Introduction to Shenandoah GC
Shenandoah GC is a garbage collector used in OpenJDK for Java applications. It is designed to achieve low pause times and enable high throughput for applications with large heaps. It utilizes Concurrent Evacuation, a technique where the evacuation of live objects from one region to another is done concurrently with application execution.
Concurrent Evacuation Start
Concurrent Evacuation Start is a phase in Shenandoah GC where the evacuation process begins while the application is still running. This phase aims to minimize the time spent in the stop-the-world (STW) phase by overlapping it with the concurrent marking and evacuation phases.
During the Concurrent Evacuation Start phase, the Shenandoah GC identifies regions with a high density of garbage objects and schedules the evacuation of live objects from these regions. By identifying and evacuating garbage early on, Shenandoah GC reduces the work required in later phases, resulting in shorter pause times.
Concurrent Evacuation Stats
Concurrent Evacuation Stats provide insights into the performance of the concurrent evacuation phase in Shenandoah GC. These stats can help developers understand how efficiently the evacuation process is working and detect any performance bottlenecks.
Some of the important stats include:
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Concurrent Evacuation Time: This stat measures the time taken by the concurrent evacuation phase. Monitoring this stat helps in evaluating the efficiency of the evacuation process and identifying any potential performance issues.
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Evacuation Rate: This stat calculates the rate at which objects are evacuated during the concurrent evacuation phase. A higher evacuation rate indicates faster object evacuation and better performance.
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Concurrent Evacuation Failure: This stat indicates if the concurrent evacuation phase failed to complete before the STW phase, resulting in a fallback to the stop-the-world evacuation. Monitoring this stat helps in identifying any issues or constraints that may impact concurrent evacuation.
Conclusion
Concurrent Evacuation Start and Concurrent Evacuation Stats are crucial components of the Shenandoah GC in Java applications. By overlapping the evacuation process with application execution and providing insights into the evacuation phase’s performance, these features contribute to reducing pause times and improving overall garbage collection efficiency.
Utilizing Shenandoah GC and understanding these features can significantly benefit applications that require low latency and high throughput. With the ability to perform concurrent evacuation, developers can ensure that their Java applications meet the demands of modern, fast-paced environments.
Remember to enhance your Java application’s garbage collection performance by leveraging the power of Shenandoah GC and monitoring the concurrent evacuation stats.
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