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Monitoring java native memory

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问题 We are monitoring jvm metrics like heap, metaspace, threads and gc count and we are able to push these metrics to monitorng server like prometheus. Similarly we wanted to track Java native memory metrics(output of jcmd VM.sumary). My question is, is it possible to get these metrics by calling any jvm runtime classes? 回答1: Yes, it is possible to get NativeMemoryTracking summary directly from a Java application: import javax.management.JMException; import javax.management.ObjectName; import

Monitoring java native memory

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Java process memory usage deviation from jcmd committed memory

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I'm seeing large variations in memory usage for a java process (running in docker), when compared to the memory usage as reported by jcmd which is tracking the JVM process. The JVM memory usage according to jcmd is quite stable but the memory usage from ps (RSS) is constantly growing by approx double the JVM committed memory variance. The JVM variance is caused by small code cache increases and small internal memory increases. Questions: What can cause such variance and how can I track it to fix the root cause? Why is there such a large variance between the memory usage as reported by ps and

What is contained in code/internal sections of JCMD?

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问题 Dimensioning a docker container for a JVM based service is tricky (as we all know). I'm pretty sure we have slightly under-dimensioned a container and want to clear up a few questions I have relating to specific jcmd (Native Memory Tracker) outputs that we see when monitoring. Questions: Are Direct Byte Buffers included in "Internal" as reported by jcmd? What else apart from code cache is in "Code" as reported by jcmd? Is there a good way to limit the "Code" section as reported by jcmd. I