I am using the following JVM parameters to start-up a JVM with the hostpot debugger.
-Xdebug -Xrunjdwp:server=y,transport=dt_socket,address=0
Note that I am assigning port zero, so that the JVM asks the OS for an ephemeral port. This is critical for my use-case, to make sure the JVM will not fail to start-up due to contention for some pre-defined port.
As a result my JVM starts-up, and the following log entry is outputted to stdout
:
Listening for transport dt_socket at address: XXXX
I would like to find some way to identify the debug port from inside or outside of the JVM, so it would be possible for me to record it in a state management serverice.
What options are available for this use-case? I have considered the following, with little joy:
From within VM:
Properties props = sun.misc.VMSupport.getAgentProperties();
System.out.println(props.getProperty("sun.jdwp.listenerAddress"));
From outside application:
VirtualMachine vm = com.sun.tools.attach.VirtualMachine.attach(PID);
try {
Properties props = vm.getAgentProperties();
System.out.println(props.getProperty("sun.jdwp.listenerAddress"));
} finally {
vm.detach();
}
Both are not a part of a standard. Applicable only to OpenJDK / Oracle JDK.
Maybe something you could start with.
netstat -tlnp
This gives you a list of all processes listening on a local TCP port. For example:
tcp 0 0 0.0.0.0:35688 0.0.0.0:* LISTEN 26733/java
35688 - the ephemeral port java - the program name which is listening 26733 - the PID of the process
If you need a finer granularity of the java processes you could use ps
to gather informations about the process.
ps x -p 26733
could return something like
26733 pts/1 0:00 java -Xdebug -Xrunjdwp:server=y,transport=dt_socket,address=0 Scratch
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.