jconsole - Connecting to a Local JMX Agent

This section provides a tutorial example on how to run 'jconsole' to connect to a JMX agent running on a local machine, and how to monitor the running Java application by reading head memory usage, CPU usage, number of threads and classes.

If you follow the tutorial presented in the previous section, the PrimeNumberSeeker.java is running in a JVM with the default JMX agent turned on.

Now we can run "jconsole" to connect to this JVM to monitor how my PrimeNumberSeeker.java is running in two ways:

1. Find out the PID (Process ID) of this JVM and use the "jconsole <pid>" command to start "jconsole" and connect to this JVM on the local machine.

2. Use the "jconsole" command to start "jconsole". It will search for any JVM process that has the local JMX agent turned on. You can make the connection by clicking the search result list.

Obviously, the second way is better, because I don't have figure out the PID of my running JVM process. Here what I did to run "jconsole" and connect it to the JVM that runs PrimeNumberSeeker.java:

1. Run "jconsole" command. The connection window shows up with 2 JVM listed in the local processes section:

Name                                        PID

jdk.jconsole/sun.tools.jconsole.JConsole   2204
PrimeNumberSeeker                           736 

2. Double click the name "PrimeNumberSeeker", the Java Monitoring & Management Console window shows with the Overview tab opened as shown in the picture below:

jconsole Overview Tab
jconsole Overview Tab

Cool. "jconsole" automatically collects some basic statistics like: heap memory usage, number of threads, number of classes, and CPU usage.

Last update: 2018.

Table of Contents

 About This Book

 Java Tools Terminology

 Java Tools Included in JDK

 javac - The Java Program Compiler

 jar - The JAR File Tool

 jlink - The JRE Linker

 jmod - The JMOD File Tool

 jimage - The JIMAGE File Tool

 java - The Java Program Launcher

 jdb - The Java Debugger

 jcmd - The JVM Diagnostic Tool

jconsole - Java Monitoring and Management Console

 JMX Technology and jconsole Tool

 jconsole - Command Options and Connection Window

 com.sun.management.jmxremote - JMX Agent for Local Connection

jconsole - Connecting to a Local JMX Agent

 com.sun.management.jmxremote.port - JMX Agent for Remote Connection

 jconsole - Connecting to a Remote JMX Agent

 jstat - JVM Statistics Monitoring Tool

 JVM Troubleshooting Tools

 jvisualvm (Java VisualVM) - JVM Visual Tool

 jmc - Java Mission Control

 javap - The Java Class File Disassembler

 keytool - Public Key Certificate Tool

 jarsigner - JAR File Signer

 jshell - Java Language Shell

 native2ascii - Native-to-ASCII Encoding Converter

 Outdated Tutorials

 References

 Full Version in PDF/EPUB