Java Management Extensions (JMX) is a
Java
Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...
technology that supplies tools for managing and monitoring
applications, system objects, devices (such as
printers) and service-oriented networks. Those resources are represented by objects called MBeans (for ''
Managed Bean''). In the API,
class
Class, Classes, or The Class may refer to:
Common uses not otherwise categorized
* Class (biology), a taxonomic rank
* Class (knowledge representation), a collection of individuals or objects
* Class (philosophy), an analytical concept used d ...
es can be dynamically loaded and instantiated.
Managing and monitoring applications can be designed and developed using the Java Dynamic Management Kit.
JSR 003 of the
Java Community Process
The Java Community Process (JCP), established in 1998, is a formal mechanism that enables interested parties to develop standard technical specifications for Java technology. Becoming a member of the JCP requires solid knowledge of the Java program ...
defined JMX 1.0, 1.1 and 1.2. JMX 2.0 was being developed under JSR 255, but this JSR was subsequently withdrawn. The JMX Remote API 1.0 for remote management and monitoring is specified by JSR 160. An extension of the JMX Remote API for Web Services was being developed under JSR 262.
Adopted early on by the
J2EE community, JMX has been a part of
J2SE since version 5.0. "JMX" is a trademark of
Oracle Corporation
Oracle Corporation is an American Multinational corporation, multinational computer technology company headquartered in Austin, Texas. Co-founded in 1977 in Santa Clara, California, by Larry Ellison, who remains executive chairman, Oracle was ...
.
Architecture

JMX uses a three-level architecture:
# The ''Probe'' level – also called the ''Instrumentation'' level – contains the probes (called
MBeans)
instrumenting the resources
# The ''Agent'' level, or MBeanServer – the core of JMX. It acts as an intermediary between the MBean and the applications.
# The ''Remote Management'' level enables remote applications to access the MBeanServer through connectors and adaptors. A connector provides full remote access to the MBeanServer API using various communication (
RMI,
IIOP,
JMS,
WS-* …), while an adaptor adapts the API to another protocol (
SNMP, …) or to Web-based GUI (
HTML
Hypertext Markup Language (HTML) is the standard markup language for documents designed to be displayed in a web browser. It defines the content and structure of web content. It is often assisted by technologies such as Cascading Style Sheets ( ...
/
HTTP
HTTP (Hypertext Transfer Protocol) is an application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web, wher ...
,
WML/
HTTP
HTTP (Hypertext Transfer Protocol) is an application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web, wher ...
, …).
Applications can be generic consoles (such as
JConsole and
MC4J) or domain-specific (monitoring) applications. External applications can interact with the MBeans through the use of JMX connectors and protocol adapters. Connectors serve to connect an agent with a remote JMX-enabled management application. This form of communication involves a connector in the JMX agent and a connector client in the management application.
The
Java Platform, Standard Edition
Java Platform, Standard Edition (Java SE) is a computing platform for development and deployment of porting, portable code for desktop computer, desktop and server (computing), server environments. Java SE was formerly known as Java 2 Platform, S ...
ships with one connector, the RMI connector, which uses the Java Remote Method Protocol that is part of the
Java remote method invocation API. This is the connector which most management applications use.
Protocol adapters provide a management view of the JMX agent through a given protocol. Management applications that connect to a protocol adapter are usually specific to the given protocol.
Managed beans
A managed bean – sometimes simply referred to as an ''MBean'' – is a type of
JavaBean, created with
dependency injection
In software engineering, dependency injection is a programming technique in which an object or function receives other objects or functions that it requires, as opposed to creating them internally. Dependency injection aims to separate the con ...
. Managed Beans are particularly used in the Java Management Extensions technology – but with Java EE 6 the specification provides for a more detailed meaning of a managed bean.
The MBean represents a resource running in the
Java virtual machine
A Java virtual machine (JVM) is a virtual machine that enables a computer to run Java programs as well as programs written in other languages that are also compiled to Java bytecode. The JVM is detailed by a specification that formally descr ...
, such as an application or a Java EE technical service (transactional monitor, JDBC driver, etc.). They can be used for collecting statistics on concerns like performance, resources usage, or problems (pull); for getting and setting application configurations or properties (push/pull); and notifying events like faults or state changes (push).
Java EE 6 provides that a managed bean is a bean that is implemented by a Java class, which is called its bean class. A top-level Java class is a managed bean if it is defined to be a managed bean by any other Java EE technology specification (for example, the
JavaServer Faces technology specification), or if it meets all of the following conditions:
# It is not a non-static inner class.
# It is a concrete class, or is annotated
@Decorator
.
# It is not annotated with an EJB component-defining annotation or declared as an EJB bean class in
ejb-jar.xml
.
No special declaration, such as an annotation, is required to define a managed bean.
A MBean can notify the MBeanServer of its internal changes (for the attributes) by implementing the
javax.management.NotificationEmitter
. The application interested in the MBean's changes registers a listener (
javax.management.NotificationListener
) to the MBeanServer. Note that JMX does not guarantee that the listeners will receive all notifications.
Types
There are two basic types of MBean:
* ''Standard MBeans'' implement a business interface containing setters and getters for the attributes and the operations (i.e., methods).
* ''Dynamic MBeans'' implement the
javax.management.DynamicMBean
interface that provides a way to list the attributes and operations, and to get and set the attribute values.
Additional types are ''Open MBeans'', ''Model MBeans'' and ''Monitor MBeans''. ''Open MBeans'' are dynamic MBeans that rely on the basic data types. They are self-explanatory and more user-friendly. ''Model MBeans'' are dynamic MBeans that can be configured during runtime. A generic MBean class is also provided for dynamically configuring the resources during program runtime.
A MXBean (''Platform MBean'') is a special type of MBean that
reifies Java virtual machine
A Java virtual machine (JVM) is a virtual machine that enables a computer to run Java programs as well as programs written in other languages that are also compiled to Java bytecode. The JVM is detailed by a specification that formally descr ...
subsystems such as
garbage collection,
JIT compilation,
memory pools,
multi-threading, etc.
A MLet (''Management applet'') is a utility MBean to load, instantiate and register MBeans in a MBeanServer from an
XML
Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing data. It defines a set of rules for encoding electronic document, documents in a format that is both human-readable and Machine-r ...
description. The format of the XML descriptor is:
ODEBASE = ''codebaseURL'' AME = ''objectName'' ERSION = ''version'' >
rglist
Support
JMX is supported at various levels by different vendors:
* JMX is supported by Java
application servers such as OpenCloud Rhino Application Serve
JBoss, JOnAS,
WebSphere Application Server,
WebLogic
Oracle Fusion Middleware (FMW, also known as Fusion Middleware) consists of several software products from Oracle Corporation. FMW spans multiple services, including Java EE and developer tools, integration services, business intelligence, co ...
,
SAP NetWeaver Application Server,
Oracle Application Server 10g and
Sun Java System Application Server.
* JMX is supported by the UnboundID Directory Server, Directory Proxy Server, and Synchronization Server.
*
Systems management
Systems management is enterprise-wide System administration, administration of distributed systems including (and commonly in practice) computer systems. Systems management is strongly influenced by network management initiatives in telecommunic ...
tools that support the protocol include
Empirix OneSight, GroundWork Monitor,
Hyperic,
HP OpenView,
IBM Director, ITRS Geneos,
Nimsoft NMS,
OpenNMS,
Zabbix,
Zenoss Core, and Zyrion,
SolarWindsUptime Infrastructure Monitor and LogicMonitor.
* JMX is also supported by
servlet containers such as
Apache Tomcat. &
Jetty (web server)
*
MX4Jbr>
is Open Source JMX for Enterprise Computing.
*
jManagebr>
is an open source enterprise-grade JMX Console with Web and command-line interfaces.
*
MC4Jbr>
is an open source visual console for connecting to servers supporting JMX
*
snmpAdaptor4jbr>
is an open source providing a simple access to MBeans via the SNMP protocol.
jvmtopis a lightweight open source JMX monitoring tool for the command-line
*
Prometheus (software), Prometheus can ingest JMX data via the JMX exporter which exposes metrics in Prometheus format.
*
New Relic's on-host infrastructure agent collects JMX data which is shown in various charts in its
observability platform's dashboard.
Jolokiais a Java agent that exposes JMX over HTTP for easy access from non-Java systems.
See also
*
Jini
*
Network management
*
Simple Network Management Protocol
Simple Network Management Protocol (SNMP) is an Internet Standard protocol for collecting and organizing information about managed devices on IP networks and for modifying that information to change device behavior. Devices that typically su ...
References
Further reading
Articles
*
Enabling Component Architectures with JMX
by Marc Fleury and Juha Lindfors
*
by Andreas Schaefer
* "Java in the management sphere" by Max Goff 1999
*
*
*
– The microkernel
In computer science, a microkernel (often abbreviated as μ-kernel) is the near-minimum amount of software that can provide the mechanisms needed to implement an operating system (OS). These mechanisms include low-level address space management, ...
design
*
by Rakesh Kalra Jan 16, 2006
*
" by Lucas McGregor
Books
* Benjamin G Sullins, ''Mark B Whipple : JMX in Action: You will also get your first JMX application up and running'', Manning Publications Co. 2002,
* J. Steven Perry: ''Java Management Extensions'', O'Reilly,
* Jeff Hanson: ''Connecting JMX Clients and Servers: Understanding the Java Management Extensions'', APress L. P.,
* Marc Fleury, Juha Lindfors: ''JMX: Managing J2EE with Java Management Extensions'', Sams Publishing,
External links
JMX 1.4
(JMX 1.4, part of Java 6)
JMX at JBoss.com
JSR 255
(JMX 2.0)
JSR 3
(JMX 1.0, 1.1, and 1.2)
{{Jakarta EE
Java APIs
Management Extensions
Management Extensions
Network management