Java remote debugging connection refused

Question

I get connection refused when remotely debugging a Java application that executes on a different server. The JVM is version 16, and the OS is Ubuntu 21.04. I chose 8999 as an unused port on the server. Not much help from Oracle documentation on runjdwp.

The command line options are ...

-Xdebug \
-Xrunjdwp:transport=dt_socket,address=8999,server=y,suspend=y \

Answer 1

The socket 8999 on the remote host defaults to 127.0.0.1:8999 which only accepts connections from running on the same host. In order to accept connections from any host, I found that the following worked OK.

-Xdebug \
-Xrunjdwp:transport=dt_socket,address=0.0.0.0:8999,server=y,suspend=y \