JMX Update

1
JMX Update

• Scott Molenaar
• ScottMolenaar_at_null.net
• 11/08/2004

2
Original Slides Created by

• David Moran
• dmoran_at_nc.rr.com
• 10/20/03

3
Agenda

• Overview
• Managed Beans
• Services
• Remote API
• J2EE Management
• Implementations
• Future Directions
• Demo

4
Benefits

• JMX is an API to for managing java applications.
• Abstract the instrumentation for management
  information to a common interface to facilitate
  integrated management.
• Distribute management by moving management
  functions to the agents.
• Real-time deployment of services and updates.
• Possible to use to manage any application or
  device (via JNI or SNMP etc..)

5
JMX Architecture
6
MBeanServer

• The core of the agent. It provides a registry for
  MBeans.
• Allows clients to discover and execute operations
  exposed by the MBeans
• Makes available various services to facilitate
  management (I.e. monitoring, scheduling, etc)
• Use ObjectName class to register objects with
  the MBeanServer

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Instrument your resources as MBeans

• MBean stands for managed bean
• MBeans can represent a physical device or an
  application
• You decide which attributes and methods you want
  to expose for management.
• Use design patterns similar to JavaBeans
• MBeans are exposed in an agent.

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Standard MBeans

• The simplest MBean
• Provides a static representation of a manageable
  resource.
• Implements a management interface of attributes
  and methods that a device or application exposes
  for management.

9
Notifications

• Can be used to inform registered listeners with
  important events or state changes.
• Similar to the java event model
• Register once to all types of notifications
• Can supply a filter to say which notifications it
  is interested in.

10
Dynamic MBeans

• Useful if the management interface is not stable.
• The management interface is defined at runtime.
• Developer is responsible for checking the
  validity of the invocations.

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DynamicMBean Interface
ltltInterfacegtgt DynamicMBean
getAttribute(String attribute) setAttribute(Attrib
ute attribute) getAttributes (String
attributes) setAttributes(AttibuteList
attributes) getMBeanInfo() invoke(String
actionName, Object params)
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Model MBeans

• Most flexible and thus most complicated MBeans
• Extension of the dynamic MBean
• Developers do not write an MBean class
• The agent must supply the RequiredModelMBean and
  the Management Interface is defined outside of
  the Bean via setter methods.
• Features include persistence, logging, and
  attribute caching.

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Connectors/Adapters

• A connector makes a Java Management Extensions
  (JMX) API MBean server accessible to remote Java
  technology-based clients.
• Adapters are similar to connectors except they
  provide protocol translations (I.e. SNMP, HTML,
  etc.)

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Agent Services

• Mlet (Management Applet) Dynamically adds class
  files to the server either locally or from a
  remote location.
• Relation Service Allows the definition of
  relationships between MBeans
• Monitors Observe MBean attributes and emit
  notifications when values change.
• Timers Emits user defined notifications at
  specific times.

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JMX Remote API

• Adds remote capability to the JMX spec
• Makes the JMX agent accessible from outside the
  JVM.
• Developed through the JCP JSR 160
• Standard support via RMI
• Optional support via TCP Sockets (JMXMP)
• API is as close as possible to the API defined by
  the JMX API.
• Also support discovery/lookup services and
  defines security between the client and server.
• As with RMI code must handle communication
  exceptions

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J2EE Management

• An MBean can get data directly from an EJB by
  invoking its access methods.
• An MBean can receive data being pushed from an
  EJB.
• Registers and Deletes an MBean with a JMX agent
  upon creation and destruction of an EJB

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J2EE Management Spec JSR77

• This specification represents a model of the J2EE
  application server, and its subcomponents, that
  all J2EE-compliant application vendors are
  required to expose
• Requires JMX
• Part of J2EE 1.4 spec
• Specifies the MEJB, which is a session bean, to
  expose the agent to remote clients.

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Available JMX Implementations

• Sun JDK1.5
• JBOSS JBOSS-MX
• MX4J
• XMOJO
• Commercial implementations available
• Weblogic
• Adventnet
• XtreamJ
• WebSphere Tivioli

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Future Directions

• Use of metadata
• Persistence
• Reliable event handling
• Master-agent/sub-agent functionality
• Manageability for J2EE apps

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Examples

• MX4J - Dynamic MBean Example (CacheMBean) MC4J
  Console
• XMOJO - Model MBean Example (ServerInfo) XMOJO
  Web based console
• JBoss XMBean Example (CacheMBean)
• JBoss Web based console MC4J Console
• JDK1.5 Standard MBeans and JConsole

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Books

• JMX in ActionBenjamin G. Sullins,
  Mark WhipplePublisher Manning Publications
  Company
• JMX Managing J2EE with Java Management
  ExtensionsMarc Fleury, Juha Lindfors
• Publisher Sams
• Java and JMX Building Manageable
  SystemsHeather Kreger, Ward K. Harold,
  Leigh Williamson, Ward HaroldPublisher Pearson
  Education
• Java Management ExtensionsJ. Steven Perry
• Publisher O'Reilly Associates,
  Incorporated
• JMX ProgrammingMike JasnowskiPublisher Wiley,
  John Sons, Incorporated

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References

• Sun JMX Page http//java.sun.com/products/JavaMan
  agement
• JMX Forum jmx-forum_at_java.sun.com
• JBOSS MX http//www.jboss.org/developers/projects
  /jboss/jbossmx.jsp
• AdventNet www.adventnet.com
• http//www.gartner.com/reprints/adventnet/108841.h
  tml
• Interview with Chris Ebro http//www.theserverside
  .com/events/library.jsp
• JSR77 Article
• http//www.onjava.com/pub/a/onjava/2002/03/27/jsr7
  7.html
• Original Slides http//www.trijug.org/downloads/JM
  XPresentation.ppt

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References continued

• MX4J Page http//mx4j.sourceforge.org
• MC4J Page http//mc4j.sourceforge.org
• XMOJO Page http//www.xmojo.org
• Jconsole page http//java.sun.com/j2se/1.5.0/docs
  /tooldocs/share/jconsole.html
• Tutorial Page http//www.admc.com/blaine/howtos/j
  mx/jmx.html
• Article on JMX http//www.onjava.com/pub/a/onjava
  /2004/09/29/tigerjmx.html