I'm trying to remotely debug a Tomcat webapp on a recently upgraded Tomcat 9.0.13 and Open JDK 11.0.1. Server is Redhat Enterprise Linux 7.6 and I'm using Eclipse on a Windows 7 developer box to connect.
Tomcat starts, and the app is accessible on port 8080 but fails on certain requests. So on my Eclipse, I've configured a Remote Java application with my configuration details. When I try to connect to it, the connecting fails with
Failed to connect to remote VM. Connection refused.
I'm using the default port, 8000 and on the Linux server, netstat -an shows that there is a process listening on that port when Tomcat starts and not when Tomcat stops.
I've tried telnet from the Windows box to port 8000 and get
$ telnet c516vefpubrec 8000
Trying XX.XXX.XX.XX...
telnet: Unable to connect to remote host: Connection refused
When I do the same running our old Tomcat 7 + Java 1.8 everything is successful. I've tried other ports with the same result.
Could this be a bug? Is there a configuration item to enable JPDA on Tomcat 9?
I had this exact same issue. I'm running an application from a centos vm and trying to debug from my windows machine.
I had to go into the catalina.sh file on the vm and make an edit. In the section that says that handles the jpda flag, the JPA_OPTS variable needed to be changed to JPDA_OPTS="-agentlib:jdwp=transport=$JPDA_TRANSPORT,address=*:$JPDA_ADDRESS,server=y,suspend=$JPDA_SUSPEND"
Note the *: before the JPDA variable. This allows any ip address to have access to remote debugging. I believe by default it only allows local host.
Hope this helps.