I’ve been playing with JOnAS lately and have been puzzling out how to get
RMI working through a firewall. Normally RMI uses dynamic ports which
represents pain and suffering if you want to use JMX. The documentation
for JOnAS is located
here. After glancing at the JOnAS config I was disheartened to find it
wasn’t just ‘set the RMI port’. It was set the port for a particular protocol
RMI will run over:
- For the RMI/JRMP protocol, change:
carol.jrmp.server.port=0
- For the RMI/Jeremie protocol, change:
carol.jeremie.server.port=0
- For the RMI/IIOP protocol, change:
carol.iiop.server.port=0
Oh great. All those wonderful docs on JMX that I read
before didn’t exactly mention I’d have to
choose the transport protocol for RMI. Why is it everytime you try to learn
more about Java stuff it’s like falling into the rabbit hole?
So after poking around I found what I was looking for in the Javadocs
on JMX here. This is what the docs say:
The RMI connector supports both the JRMP and the IIOP transports for RMI.
Like most connectors in the JMX Remote API, an RMI connector usually has an address, which is a JMXServiceURL. The protocol part of this address is rmi for a connector that uses the default RMI transport (JRMP), or iiop for a connector that uses RMI/IIOP
So there you have it. By DEFAULT JMX will default to using JRMP but it
can also use IIOP. Lots more Java acronym soup to figure out.
References:
