Updated on 2023-11-03 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 Application > 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.

    Figure 1 Going to the JVM page

  6. On the displayed JVM tab page, select a target instance and metric to view the monitoring data in different metric sets.

    Figure 2 Selecting a target instance and metric

  7. Select a time dimension. Default: Last 20 minutes.

    Options: Last 20 minutes, Last hour, Last 3 hours, Last 6 hours, Last day, Today, Yesterday, Last 7 days, Last 30 days, or Custom.

    Figure 3 Selecting a time dimension

  8. Click in the upper right corner of the list and select the metric data you want to view.

Viewing JVM Information

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

Figure 4 Viewing JVM information
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.

Figure 5 Viewing JVM monitoring data
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

Initial Threads

Number of threads in the initial state

Running Threads

Number of running threads

Blocked Threads

Number of blocked threads

Terminated Threads

Number of terminated 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

Available Memory

Size of available memory

Initialized Memory

Size of the initialized memory

Max. Memory

Size of the maximum memory

Name

Memory pool name

Used Memory

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.

Figure 6 Viewing GC information
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.

Figure 7 Viewing threads
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 Details 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

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

0–10 ms

Number of requests with 0–10 ms response time

10–100 ms

Number of requests with 10–100 ms response time

100–500 ms

Number of requests with 100–500 ms response time

500–1000 ms

Number of requests with 500–1000 ms response time

1–10s

Number of requests with 1–10s response time

> 10s

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.