Jmx4Perl

Posted on August 18th, 2009 by roland

Jmx4Perl communication with a JEE Server (agent mode)

Jmx4Perl provides an alternative way of accessing Java JEE Server management interfaces that are based on JMX (Java Management Extensions). It is an agent-based approach where a small Java Web application (approx. 100k) deployed on the application server provides HTTP/JSON-based access to JMX MBeans registered within the application server. It is set up from a handful of Perl modules, which can be integrated seamlessly in your own Perl programs. It includes a sample Nagios check command utilizing JMX::Jmx4Perl as well as the “jmx4perl” tool, which allows for access to JMX information via the command line.

Benefits of this approach compared to the traditional way of accessing JMX remotely via JSR 160 connectors are:

• No Java installation required on the Nagios host
• Fast plugin startup times because no JVM needs to be launched.
• Support for bulk operations
• Fine grained security policies possible
• No special JEE Server startup options required in order to access JMX information remotely
• JSON serialization allows deep access into Java objects
• Firewall friendly communication via HTTP

However, since release 0.50 jmx4perl can be operated in a proxy mode where a dedicated proxy server accesses the target platform via JSR-160 JMX remoting. This allows for an agentless operation without the need of installing any extra software on the target server.

Beside these technical advantages, the JMX Nagios Plugin check_jmx4perl provides also a rich feature set:

• Access to JMX attributes and return values of JMX operations for monitoring purposes
• Incremental mode for monitoring the velocity of value changes, e.g. the growth rate of the thread count
• Relative monitoring of values by providing a base value attribute, e.g. for checking that the memory used is below 80% of the available memory
• Deep access to arbitrary Java bean attributes, e.g. the statistics values of a JSR77 Stats object
• Alias names for common attributes and operations
• Selective access to a predefined set of MBeans by providing an access policy file to the agent servlet

This plugin has been tested on JBoss 4.2.3 GA & 5.1.0 GA, Oracle Weblogic 9.2 MP3 & 10.0.2.0, IBM Websphere 6.1 & 7.0, Jonas 4.10.3 (with Jetty 5.1.10 and Tomcat 5.5.26), Apache Geronimo 2.1.4 (Jetty 6 and Tomcat 6), Glassfish 2.1 & v3, Apache Tomcat 4.1.39, 5.5.27 & 6.0.18 and Jetty 5.1.15 & 6.1.18 (with JMX enabled). Beside these, it should work on any Servlet Container running on at least Java 1.5.

‘check_jmx4perl’ is part of a larger distribution, jmx4perl. In addition to this Nagios plugin, jmx4perl contains tools for exploring and examing the available JMX MBeans on the JEE-Server so that it is easy to discover the MBeans and attributes worth monitoring.

A Mule agent for deploying on the Mule ESB Server is available, too.

You can find Jmx4Perl at CPAN.

One Response to “Jmx4Perl”

1. John Tangney Says:
   July 17th, 2010 at 11:49

   I just came across Jmx4Perl. I haven’t had a chance to try it yet, but it sounds like a great solution to our nagios/tomcat monitoring needs. Thanks! –johnt

   [Reply]

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