JMX port

[rainerfrey]

As far as I understand, the jmx.port setting in catalina.properties sets the port for the RMI registry for the remote JMX access.

Java uses per default a dynamic port for the management RMI server, which makes it impossible to create firewall exceptions.

Is this port dynamic with tcServer too? Or is it possible to use a static port? If so, is it configurable or implicit (maybe one off the registry port)?

[fhanik]

The JMX port is static, and you should be able to use it through firewalls. In order to do that, you have to configure the bind address, with an externally visible IP address, and not 127.0.0.1

[rainerfrey]

Ok, so which port does hte jmx.port property set?

[fhanik]

It sets the JMX listening port. The port that a JMX user agent will connect to, either locally or from a remote destination. No other ports are exposed.

[rainerfrey]

Well, it seems my question is not clear enough. Here a quote from the Java Monitoring and Management Guide:

As stated above, the code in Example 2-5 can be used to monitor applications through a firewall, which might not be possible if you use the out-of-the-box monitoring solution. The com.sun.management.jmxremote.port management property specifies the port where the RMI Registry can be reached but the ports where the RMIServer and RMIConnection remote objects are exported is chosen by the RMI stack.

So which of these ports is configured with the jmx.port property? The port of the RMI registry, or the port of the RMI server where the remote objects are exposed?

Or am I misunderstanding this whole thing completely and this is not about a RMI JMX connector at all?

[fhanik]

tcServer offers an enhancement to regular JMX/RMI communication. Namely to communicate over a single port.

Its no secret on how its done, here is a good blog entry
http://blogs.sun.com/jmxetc/entry/jm...irewalls_using

[rainerfrey]

Filip, thanks a lot. This is really interesting information! I didn't know this is possible at all.