Use jdk's own running monitoring tool JConsole to observe and analyze the running of Java programs

Original address: http://blog.csdn.net/libaolin198706231987/article/details/55057149

1. What is JConsole

JConsole has been introduced since Java 5. JConsole is a built-in Java performance analyzer that can be run from the command line or in a GUI shell. You can easily use JConsole (or, its higher-end "closer" VisualVM ) to monitor Java application performance and trace code in Java.

2. How to start JConsole

If you are starting from the command line, make the JDK on the PATH and run jconsole.
If starting from a GUI shell, find the JDK installation path, open the bin folder, and double-click jconsole .

When the profiling tool pops up (depending on the version of Java running and the number of Java programs running), a dialog may appear asking for the URL of a process to connect to, or it may list many different local Java processes (sometimes contains the JConsole process itself) to connect. as the picture shows:

To analyze that program, double-click the process.

3. How to set JAVA program runtime to be analyzed by JConsolse connection

Local programs (relative to the computer where JConsole is turned on), can be connected to JConsole that can be opened locally without setting any parameters (Java SE 6 does not need to set up, before it still needs to set the runtime parameter - Dcom.sun.management.jmxremote )
Unauthenticated connection (the following settings indicate that the connection port is 8999 and can be connected without authentication)
1. -Dcom.sun.management.jmxremote.port=8999 \
2. -Dcom.sun.management.jmxremote.authenticate=false \
3. -Dcom.sun.management.jmxremote.ssl=false
If security factors are considered, authentication is required, and a secure connection is required, it can be done. Reference: http://download.oracle.com/javase/6/docs/technotes/guides/management/agent.html#gdenv

Fourth, how JConsole connects to the JAVA program of the remote machine (for example)

1. Write a simple JAVA program that runs all the time, running on a certain machine such as (192.168.0.181)

java -cp . -Dcom.sun.management.jmxremote.port=8999 -Dcom.sun.managent.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false JConsoleTest

2. Connect to another machine

You can use the command directly:

jconsole.exe 192.168.0.181:8999

You can also operate the connection in the already opened JConsole interface -> create a new connection -> select a remote process -> enter the remote host IP and port number -> click "connect", as shown in the figure: