- 直接
new DirectMemReporter().startReport();调用就可以了
netty4.1x默认使用池化的bytebuf，每个池子初始16mb，使用直接内存的最大池子数默认16，由jvm启动参数决定
-Dio.netty.allocator.numDirectArenas。默认最大堆外内存默认3817865216 bytes，由-Dio.netty.maxDirectMemory决定
@Slf4j
public class DirectMemReporter {
private AtomicLong directMem = new AtomicLong();
private ScheduledExecutorService executor = MoreExecutors.getExitingScheduledExecutorService(
new ScheduledThreadPoolExecutor(1), 10, TimeUnit.SECONDS);
public DirectMemReporter() {
Field field = ReflectionUtils.findField(PlatformDependent.class, "DIRECT_MEMORY_COUNTER");
field.setAccessible(true);
try {
directMem = (AtomicLong) field.get(PlatformDependent.class);
} catch (IllegalAccessException e) {}
}
public void startReport() {
executor.scheduleAtFixedRate(() -> {
log.info("netty direct memory size:{}b, max:{}", directMem.get(), PlatformDependent.maxDirectMemory());
}, 0, 1, TimeUnit.SECONDS);
}
}
