Debugging JConsole Connection Failed

问题:

I have a web application deployed to a remote resin server, and it has JMX turned on.

I can telnet to the remote server i.e

franz@see:/tmp$ telnet <remote-ip> 5555
Trying <remote-ip>...
Connected to <remote-ip>.
Escape character is '^]'.
��sr5javax.management.remote.message.HandshakeBeginMessage�,���6profilestLjava/lang/String;Lversionq~xppt1.0^]

telnet> q
Connection closed.

But I cannot connect to it using my JConsole

$JAVA_HOME/bin/java -cp $JAVA_HOME/lib/jconsole.jar:$JAVA_HOME/lib/tools.jar:pm-common/lib/jmxremote_optional-1_0_1_3.jar sun.tools.jconsole.JConsole service:jmx:jmxmp://<remote-ip>:5555

I have tried this with the following java versions but I get a 'Connection Failed' on both instances.

## where JAVA_HOME=/opt/java/64/jdk1.5.0_22
java version "1.5.0_22"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_22-b03)
Java HotSpot(TM) 64-Bit Server VM (build 1.5.0_22-b03, mixed mode)

## where JAVA_HOME=/opt/java/64/jdk1.6.0_17
java version "1.6.0_17"
Java(TM) SE Runtime Environment (build 1.6.0_17-b04)
Java HotSpot(TM) 64-Bit Server VM (build 14.3-b01, mixed mode)

Do you guys have any idea as to how to debug this (i.e. find out what's wrong)?

回答1:

Make sure you are running your application with following java properties set

-Dcom.sun.management.jmxremote.port=9005
-Dcom.sun.management.jmxremote.authenticate=false
-Dcom.sun.management.jmxremote.ssl=false

Try to connect now. If you want to debug this ,you can run the jconsole with following command

jconsole -J-Djava.util.logging.config.file=path_to_logging.properties_for_jconsole

Below is the content of logging.properties file

Logging.properties

handlers = java.util.logging.ConsoleHandler


.level = INFO

java.util.logging.ConsoleHandler.level = FINEST

java.util.logging.ConsoleHandler.formatter = \

java.util.logging.SimpleFormatter

// Use FINER or FINEST for javax.management.remote.level - FINEST is

// very verbose...

javax.management.level = FINEST

javax.management.remote.level = FINER

Once you run jconsole a separate window will pop up displaying logs.

回答2:

if you run jconsole -debug it gives you more diagnostic info on the failure. See the Daniel Fuchs blog entry "Troubleshooting connection problems in JConsole".

I did this and it showed me I was using 32 bit jconsole the target process was started with a different (64 bit) jvm, so apparently this isn't allowed and it was thus failing.

回答3:

This finally made it work for me : Giving this extra option: -Djava.rmi.server.hostname=<ip addres where jvm is running

So all the vm arguments used to open jconsole from a remote machine, the jvm on the remote machine must be started with

 -Dcom.sun.management.jmxremote.authenticate=false  -Dcom.sun.management.jmxremote.port=<port> -Dcom.sun.management.jmxremote -com.sun.management.jmxremote.ssl=false -Djava.rmi.server.hostname=<ip address>

The entire process is listed here

回答4:

I encountered the same Problem when starting the Java-Process through cygwin. JConsole cannot connect. Started it through win7-cmd everything works as expected.

回答5:

I don't know if this is helpful, but perhaps you should use the the jconsole binary in the JDK bin directory rather than using the undocumented (and subject to change) sun.* classes to start up the console

回答6:

If your application is running on JDK 1.6 then you should be able to connect it. If it is using JDK prior to 1.6 then run it with specifying the following JVM argument

-Dcom.sun.management.jmxremote

回答7:

I was having similar issue that remote machine was behind firewall and firewall was blocking ports defined by -Dcom.sun.management.jmxremote.port and RMI 46924. After allowing me to cnnect to these port I connected succesfully.

回答8:

If you are accessing a machine behind a firewall, you need to open both JMX and RMI ports.
In this context, you are much better off forcing the value for RMI than relying on the auto assigned
In my case, I was trying to access Tomcat so I had to do the following:

#!/bin/sh
CATALINA_OPTS="$CATALINA_OPTS -Djava.net.preferIPv4Stack=true -Djava.net.preferIPv4Addresses=true -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=8008 -Dcom.sun.management.jmxremote.rmi.port=8007 -Dcom.sun.
management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false"

and then

firewall-cmd --zone=public --add-port=8008/tcp --permanent
firewall-cmd --zone=public --add-port=8007/tcp --permanent
firewall-cmd --reload