Updated on 2024-07-04 GMT+08:00

JVM

This function monitors JVMInfo, JVMMonitor, GC, thread, and JavaMethod.

Going to the JVM Page

  1. Log in to the management console.
  2. Click on the left and choose Management & Deployment > Application Performance Management.
  3. In the navigation pane, choose Application Monitoring > Metrics.
  4. In the tree on the left, click next to the target environment.
  5. Click the JVM tab. By default, the JVMMonitor information of all instances is displayed.
  6. On the displayed JVM tab page, select a target instance and monitoring item to view the monitoring data in different metric sets.
  7. Select a time range. Default: Last 20 minutes.

    Options: Last 20 minutes, Last hour, Last 3 hours, Last 6 hours, Last day, Today, Yesterday, Last week, Last month, or Custom.

    Figure 1 Selecting a time range

Viewing JVM Information

On the JVM tab page, view the JVMInfo metrics of the corresponding instance. For details about the metrics, see Table 1.

Table 1 JVMInfo metrics

Metric Set

Metric

Description

JVMInfo

JavaAgent Version

Java Agent version.

Started

JVM startup time.

Startup Parameter

JVM startup parameter.

Java Class Library Path

Java class library path.

Java Version

Java version.

Java Specification Version

Java specification version.

OS

OS name.

OS Version

OS version.

arch

CPU architecture.

Processors

Number of processors.

SDK Version

SDK version.

Viewing JVM Monitoring Data

APM monitors JVM metrics. For details about the metrics, see Table 2. JVM monitoring metrics are displayed in graphs, so that you can view and analyze JVM monitoring data more easily.

Table 2 JVM monitoring metrics

Metric Set

Metric

Description

Thread

Current Threads

Number of current threads.

Deadlock Threads

Number of deadlock threads.

Daemon Threads

Number of daemon threads.

Started Threads

Number of started threads.

Peak Threads

Peak number of threads.

Thread Status

Waiting Threads

Number of waiting threads.

Terminated Threads

Number of threads in the terminated state.

Runnable Threads

Number of runnable threads.

Blocked Threads

Number of blocked threads.

New Threads

Number of new threads.

Timed Waiting Threads

Number of threads that timed out.

Memory

Used Non-Heap Memory

Size of the used non-heap memory.

Used Heap Memory

Size of the used heap memory.

Used Direct Memory

Size of the used direct memory.

Class loading

Current Classes

Number of current classes.

Total Loaded Classes

Total number of loaded classes.

Unloaded Classes

Number of unloaded classes.

Memory pool

committed(M)

Size of available memory.

init(M)

Size of the initialized memory.

max(M)

Size of the maximum memory.

name

Memory pool name.

used(M)

Size of the used memory.

CPU

CPU Usage

CPU usage of the Java process.

Viewing GC Information

APM monitors GC metrics. For details about the metrics, see Table 2.

Table 3 GC metrics

Metric Set

Metric

Description

GC statistics

Full GC (times)

Number of full GC times in a collection period.

Full GC Duration (ms)

Full GC duration in a collection period.

Young GC (times)

Number of young GC times in a collection period.

Young GC Duration (ms)

Young GC duration in a collection period.

GC Details

GC Type

GC type, which can be major or minor.

GC Cause

GC cause.

Count

Number of times that GC has occurred.

Total GC Duration (ms)

GC duration.

Max GC Duration (ms)

Time consumed by the slowest GC.

GC Recycler

GC recycler name.

Slowest GC Details

Details about the slowest GC.

  • Click the digits in blue (such as those in the Count, Total GC Duration (ms), or Max GC Duration (ms) column) to view the corresponding GC trend graph in a certain period (default: 20 minutes).
  • On the GC details area, you can view the GC type, GC cause, count, total GC duration (ms), maximum GC duration (ms), GC recycler, and slowest GC details (details and history).

Viewing Threads

You can view the thread details of the corresponding instance on APM. For details, see Table 4.

Table 4 Thread metrics

Metric Set

Metric

Description

Thread details

Thread Name

Thread name.

Threads

Number of threads.

CPU Time (ms)

Thread CPU time.

Memory (MB)

Memory (MB).

Thread Stack

Thread stack.

  • Click a number in the Threads column to view the trend of the thread in a specified period.
  • Click Detail in the Thread Stack column to view the thread details.
  • Click History in the Thread Stack column to view the historical thread stack list.

Viewing Java Methods

  1. By default, APM does not monitor Java methods. To monitor them, configure the JavaMethod monitoring item first.
  2. After the configuration is complete, the system monitors the methods and classes of JavaMethod.
  3. On the JVM page, select a target instance and JavaMethod to view details. For details, see Table 5.
Table 5 JavaMethod metrics

Metric Set

Metric

Description

JavaMethod

Class

Class of a Java method.

Method

Method.

Calls

Number of times that the method is called.

Avg RT (ms)

Average response time.

Errors

Number of times that the method fails to be called.

Max Concurrency

Maximum concurrency of the method.

Max RT (ms)

Maximum response time of the method.

0 ms–10 ms

Number of requests with 0 ms–10 ms response time.

10 ms–100 ms

Number of requests with 10 ms–100 ms response time.

100 ms–500 ms

Number of requests with 100 ms–500 ms response time.

500 ms–1s

Number of requests with 500 ms–1s response time.

1s–10s

Number of requests with 1s–10s response time.

10s–n

Number of requests with response time longer than 10s.

  • Click a number (such as those in the Calls or Errors column) to view the trend of the thread in a specified period.