VisualGC not supported for this JVM

I was having a problem connecting the VisualGC plugin, so I found out the following:

1. It must use jstatd, and not jmx
2. I had to set up the following on my monitored node, in this case a cassandra cluster node:

vi /tmp/tools.policy
grant codebase “file:/usr/lib/jvm/java-8-openjdk-amd64/lib/tools.jar” {
 permission java.security.AllPermission;
};

3. And then I had to run jstatd on the same node:

sudo jstatd -J-Djava.security.policy=/tmp/tools.policy -J-Djava.rmi.server.hostname=10.101.32.110 -p 7198

Notice that I specified the port, 7198 above. Otherwise, it uses the default port of 1099 (I think it’s 1099).

I was then able to establish the jstatd connection, and that allowed VisualGC to work.