Question

I am running Tomcat 6 on a Linux server in Amazon’s cloud. I am trying to connect to it with VisualVM from my Mac at my office. I have allowed opened up all TCP ports between my desktop and the server, but I am unable to get VisualVM to do anything.

On the linux box, I have started Tomcat with:

-Dcom.sun.management.jmxremote
-Dcom.sun.management.jmxremote.port=9191
-Dcom.sun.management.jmxremote.ssl=false
-Dcom.sun.management.jmxremote.authenticate=false

On my Mac, I launch VisualVM and choose File -> New JMX Connection…

I enter amazonhostname.com:9191 in the box. It says “Adding amazonhostname.com:9191…” and sits there for several minutes before timing out.

From my Mac, I can “telnet amazonhostname.com 9191” just fine, and I tried some other random ports, and they all worked. I’m pretty convinced it’s not a firewall issue, unless I need to open UDP or ICMP or something like that. (Really??)

There is nothing in catalina.log on the server, or the system console on my Mac, related to jmx. netstat on the server shows 9191 and some other ports open on all interfaces.

There is no jstatd on the remote server. Is that a pre-requisite for JMX? (I am totally new to Java and I’m not even sure what those things mean, but I saw it on a blog post somewhere. I’m grasping at straws now.)

Answer 1

Set the hostname property before the VM starts:

java -Dcom.sun.management.jmxremote \
     -Dcom.sun.management.jmxremote.port=9191 \
     -Dcom.sun.management.jmxremote.authenticate=false \
     -Dcom.sun.management.jmxremote.ssl=false \
     -Djava.rmi.server.hostname=the.public.ip \
     -jar program.jar

Add the relevant rules to your security group.