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JVM monitoring

We can use the JvmStats MXBean for JVM monitoring in the Liberty profile.

Each Liberty profile instance has one JvmStats MXBean.

The ObjectName for identifying JVM MXBean is:

Available Instances = 1

This MXBean is responsible for reporting performance of JVM. Following attributes are available for JVM.

Heap Information

  • Amount of free heap available (in Bytes)

  • Total used memory by JVM for from heap (in Bytes)

  • Heap size (in Bytes)

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CPU Information

  • Percentage of CPU consumed by this JVM

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Garbage Collection (GC) Information

  • Number of times that GC happened since JVM started

  • Total time taken by GC activity

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General Information

  • Time in milliseconds since JVM has started.

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Counter definitions (Attributes to MXBean)

  • Heap: Heap size used for current JVM.

  • FreeMemory: Free heap available for current JVM.

  • UsedMemory: Used heap for current JVM.

  • ProcessCPU: Percentage of CPU used by JVM process.

  • GcCount: Number of times GC has happened since JVM starts.

  • GcTime: Total accumulated value of GC time.

  • UpTime: Time in milliseconds, since JVM has started.

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Management Interface

The management interface of JVM monitoring is com.ibm.websphere.monitor.jmx.JvmMXBean. We can use the management interface to obtain a proxy object. See Examples of accessing MBean attributes and operations.

For more information about the management interface, see the Java API document for the Liberty profile. The Java API documentation for each Liberty profile API is detailed in the Programming Interfaces (APIs) section of the information center, and is also available as a separate .zip file in one of the javadoc subdirectories of the ${wlp.install.dir}/dev directory.


Parent topic: Monitoring the Liberty profile