Java Management Extensions (JMX) is a technology for managing and monitoring Java applications. JMX instructs application developers how to instrument their applications to expose metrics and management mechanisms, and instructs operations teams how to collect metrics and manage Java applications. JMX is ubiquitous: there are a large number of off-the-shelf commercial and open source tools which speak JMX.
This article is intended for application developers to introduce JMX, to teach them how to create some simple metrics via JMX, and to encourage them to thoroughly instrument their applications with JMX.; This article uses only J2SE 5 and the Java Servlet specification. There may be better, more efficient, or more appropriate ways to add JMX counters to applications using other frameworks. For example, Spring developers should read http://static.springsource.org/spring/docs/2.0.x/reference/jmx.html.
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