Java G1：监控生产环境中的内存泄漏

是的，JVM为您提供了足够的工具来检索G1的此类信息。例如，您可以使用类似此类的内容来打印有关垃圾回收的所有详细信息（只需调用）：MemoryUtil.startGCMonitor()

public class MemoryUtil {

    private static final Set<String> heapRegions;

    static {
        heapRegions = ManagementFactory.getMemoryPoolMXBeans().stream()
                .filter(b -> b.getType() == MemoryType.HEAP)
                .map(MemoryPoolMXBean::getName)
                .collect(Collectors.toSet());
    }

    private static NotificationListener gcHandler = (notification, handback) -> {
        if (notification.getType().equals(GarbageCollectionNotificationInfo.GARBAGE_COLLECTION_NOTIFICATION)) {
            GarbageCollectionNotificationInfo gcInfo = GarbageCollectionNotificationInfo.from((CompositeData) notification.getUserData());
            Map<String, MemoryUsage> memBefore = gcInfo.getGcInfo().getMemoryUsageBeforeGc();
            Map<String, MemoryUsage> memAfter = gcInfo.getGcInfo().getMemoryUsageAfterGc();
            StringBuilder sb = new StringBuilder(250);
            sb.append("[").append(gcInfo.getGcAction()).append(" / ").append(gcInfo.getGcCause())
                    .append(" / ").append(gcInfo.getGcName()).append(" / (");
            appendMemUsage(sb, memBefore);
            sb.append(") -> (");
            appendMemUsage(sb, memAfter);
            sb.append("), ").append(gcInfo.getGcInfo().getDuration()).append(" ms]");
            System.out.println(sb.toString());
        }
    };

    public static void startGCMonitor() {
        for(GarbageCollectorMXBean mBean: ManagementFactory.getGarbageCollectorMXBeans()) {
            ((NotificationEmitter) mBean).addNotificationListener(gcHandler, null, null);
        }
    }

    public static void stopGCMonitor() {
        for(GarbageCollectorMXBean mBean: ManagementFactory.getGarbageCollectorMXBeans()) {
            try {
                ((NotificationEmitter) mBean).removeNotificationListener(gcHandler);
            } catch(ListenerNotFoundException e) {
                // Do nothing
            }
        }
    }

    private static void appendMemUsage(StringBuilder sb, Map<String, MemoryUsage> memUsage) {
        memUsage.entrySet().forEach((entry) -> {
            if (heapRegions.contains(entry.getKey())) {
                sb.append(entry.getKey()).append(" used=").append(entry.getValue().getUsed() >> 10).append("K; ");
            }
        });
    }
}

在此代码中，为您提供了足够的信息，以将次要集合与主要/混合集合分开。gcInfo.getGcAction()

但是，使用您的方法（带有阈值）到G1有一个重要的警告。G1 中的单个混合集合通常只影响几个旧的 gen 区域 - 许多区域足以释放足够的内存量，但不会太多以保持 GC 暂停较低。因此，在G1中混合收集后，您无法确定所有垃圾都已消失。因此，您需要找到更复杂的策略来检测内存泄漏（可能基于集合频率，从多个集合中收集统计信息等）。