Ivan Mushketyk Ivan Mushketyk - 2 months ago 26
Java Question

JMX connection refused

I am unable to connect to JMX object. Here is how I create a JMX object:

public static void main(String... args) {
MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
try {
ObjectName name = new ObjectName("org.javasimon.jmx.example:type=Simon");
if (mbs.isRegistered(name)) {
mbs.unregisterMBean(name);
}
SimonManagerMXBean simonManagerMXBean = new SimonManagerMXBeanImpl(SimonManager.manager());
mbs.registerMBean(simonManagerMXBean, name);
System.out.println("SimonManagerMXBean registerd under name: "+name);

} catch (JMException e) {
System.out.println("SimonManagerMXBean registration failed!\n"+e);
}

while (true) {
// waiting for connections
}
}


This is a code for connecting to the remote JMX object:

JMXServiceURL url = new JMXServiceURL("service:jmx:rmi://127.0.0.1:9999/jndi/rmi://127.0.0.1:1099/jmxrmi");
JMXConnector jmxc = JMXConnectorFactory.connect(url, null);
MBeanServerConnection mbsc = jmxc.getMBeanServerConnection();
SimonManagerMXBean simonManagerMXBean = JMX.newMXBeanProxy(mbsc, new ObjectName("org.javasimon.jmx.example:type=Simon"), SimonManagerMXBean.class);
return simonManagerMXBean;


Unfortunatelly I receive the following error:

java.io.IOException: Failed to retrieve RMIServer stub: javax.naming.ServiceUnavailableException [Root exception is java.rmi.ConnectException: Connection refused to host: 127.0.0.1; nested exception is:
java.net.ConnectException: Connection refused: connect]
at javax.management.remote.rmi.RMIConnector.connect(RMIConnector.java:338)
at javax.management.remote.JMXConnectorFactory.connect(JMXConnectorFactory.java:248)
at my.code.RemoteSimonManagerFactoryImpl.createSimonManager(RemoteSimonManagerFactoryImpl.java:24)
at my.code.Demo.main(DemoAggregation.java:21)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)
Caused by: javax.naming.ServiceUnavailableException [Root exception is java.rmi.ConnectException: Connection refused to host: 127.0.0.1; nested exception is:
java.net.ConnectException: Connection refused: connect]
at com.sun.jndi.rmi.registry.RegistryContext.lookup(RegistryContext.java:101)
at com.sun.jndi.toolkit.url.GenericURLContext.lookup(GenericURLContext.java:185)
at javax.naming.InitialContext.lookup(InitialContext.java:392)
at javax.management.remote.rmi.RMIConnector.findRMIServerJNDI(RMIConnector.java:1886)
at javax.management.remote.rmi.RMIConnector.findRMIServer(RMIConnector.java:1856)
at javax.management.remote.rmi.RMIConnector.connect(RMIConnector.java:255)
... 9 more
Caused by: java.rmi.ConnectException: Connection refused to host: 127.0.0.1; nested exception is:
java.net.ConnectException: Connection refused: connect
at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:601)
at sun.rmi.transport.tcp.TCPChannel.createConnection(TCPChannel.java:198)
at sun.rmi.transport.tcp.TCPChannel.newConnection(TCPChannel.java:184)
at sun.rmi.server.UnicastRef.newCall(UnicastRef.java:322)
at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)
at com.sun.jndi.rmi.registry.RegistryContext.lookup(RegistryContext.java:97)
... 14 more
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:351)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:213)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:200)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:529)
at java.net.Socket.connect(Socket.java:478)
at java.net.Socket.<init>(Socket.java:375)
at java.net.Socket.<init>(Socket.java:189)
at sun.rmi.transport.proxy.RMIDirectSocketFactory.createSocket(RMIDirectSocketFactory.java:22)
at sun.rmi.transport.proxy.RMIMasterSocketFactory.createSocket(RMIMasterSocketFactory.java:128)
at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:595)
... 19 more


If I try to connect to my JMX server (as to local process) using "jconsole" utility, I first get "ConnectionFailedSSL1" error, but when I click "Insecure" button in the error form, I connect successfully.

Both server and client are on the same computer.

I am using Windows 7 x64. Windows firewall is disabled.

Answer

Caused by: java.rmi.ConnectException: Connection refused to host: 127.0.0.1; nested exception is:

Most likely you are not running your server with the right JVM parameters. Jconsole uses a different mechanism to find and to connect to local processes. Your client code is trying to use TCP/IP to connect to your server. To turn this on you'll need to add something like the following to your Java command line on your server:

-Dcom.sun.management.jmxremote
-Dcom.sun.management.jmxremote.port=1099

See: How to activate JMX on my JVM for access with jconsole?

As an aside, you might want to consider using my SimpleJMX library which does all this code for you. It includes a JMX client code as well.