JMX
JMX
JMX Benefits
The recommendation is to use Java's Management eXtension (JMX) framework on the Java based systems (Tomcat, RMI Servers, etc.).
The JMX technology supports monitoring Java based applications. JMX has been incorporated into the Java Stand Edition (J2SE) platform since version 5.0. JMX will provide information related to memory usage, threads and CPU with the JVM. JMX statistical information gathering is an out of box function within each Java application running on JVM version 1.5 or higher. This information is automatically gathered by the Java VM. The change will be to expose this information to be access remotely.
The information should help to pin-point the areas of concern within the reviewed applications. This information will be used to identify some of the application code issues. The information gathered will be coupled with various other system assessment strategies.
JConsole is a general JMX client. The JConsole client will be used by the performance integration technical team to review the JVM heap usage, memory, threads and other key monitoring information. The following is a view of JConsole;
Pros
The following are some of the typical benefits of using JMX in a Java system.
- JMX is a Java production supported technology. It is used by open source and commercial J2EE application servers as a standard technology.
- Enables Java application monitoring at a JVM level without a heavy investment or third party tools (verses JProfiler)
- JMX is part of the J2ES and J2EE standard platform.
- Utilizes Java's "Out of box" monitoring and management of the Java Virtual Machine
- The exposed JMX interfaces will only allow read-only requests through the JMX monitorRole role
- Supports open source or commercial JMX based JVM statistical reporting tools
- Supports the possibility of adding future management functions such as JVM based monitoring notifications and on demand JVM garbage collection.
See the following link for additional reasons why JMX should be used in Java based systems
Cons
- Each remote connection will impact the JVM based on the number of connections plus the number of requests to access the retrieved information. Connections to the JMX services via clients such as JConsole must be limited so that application performance may not be affected. This will be a small impact assuming a small number of JMX clients (the performance integration technical team).
JMX implementation
JMX remote monitoring will use password authentication. The authentication will be setup for the Java server environments.
Tomcat Setup
- Login as the "tomcat" user
- Copy the password template file, ${JRE_HOME}/lib/management/jmxremote.password.template, to /opt/tomcat/apache-tomcat-5.5.12/conf /jmxremote.password
- Set file permissions so that only the owner can read and write the password file.
- chmod 600 /opt/tomcat/apache-tomcat-5.5.12/conf/jmxremote.password
- Add password for role such as monitorRole in /opt/tomcat2/apache-tomcat-5.5.12/conf /jmxremote.password (last line in jmxremote.password file)
- Backup "catalina.sh" and "shutdown.sh"
- Copy /opt/tomcat2/apache-tomcat-5.5.12/bin/catalina.sh to /opt/tomcat2/apache-tomcat-5.5.12/bin/catalina-shutdown.sh
- Add the following JVM arguments to /opt/tomcat2/apache-tomcat-5.5.12/bin/catalina.sh (look for JAVA_OPTS)
-Dcom.sun.management.jmxremote.port=7010
-Dcom.sun.management.jmxremote.authenticate=true
-Dcom.sun.management.jmxremote.ssl=false
-Dcom.sun.management.jmxremote.password.file=/opt/tomcat2/apache-tomcat-5.5.12/conf//jmxremote.password
- Edit /opt/tomcat2/apache-tomcat-5.5.12/bin/catalina-shutdown.sh
- Edit /opt/tomcat2/apache-tomcat-5.5.12/bin/shutdown.sh
- Change "EXECUTABLE=catalina.sh" to "EXECUTABLE=catalina-shutdown.sh"
Windows JMX Password Security Restriction Setup
See the following URL for details
http://download.oracle.com/javase/6/docs/technotes/guides/management/security-windows.html
Also note you must change owner of the file to the security user
Right Click -> Properties -> Security -> Advance -> Owner -> Select a user -> Click OK
JMX Verification
- Restart the Tomcat server on the server
- From a laptop (with JDK version 1.5 or higher)
- Click Start -> run -> jconsole.exe
- Connect to tomcat JMX
- Select Remote Process
- Enter ${server-name}:7010
- Username: monitorRole
- Password: ${password}
See the following for details
http://tomcat.apache.org/tomcat-6.0-doc/windows-service-howto.html#Command_line_arguments
on server
Click Start -> run
Enter "cmd"
Type d:
cd D:\Sciquest\Tomcat6.0\bin
Enter (one line)
tomcat6.exe //US//"Apache Tomcat 6" --JvmOptions -Xrs -Dcom.sun.management.jmxremote.port=7002
-Dcom.sun.management.jmxremote.authenticate=true
-Dcom.sun.management.jmxremote.ssl=false
-Dcom.sun.management.jmxremote.password.file=
