What is it?
The Geronimo monitoring plug-in is broken down between server and client plug-ins, referred to as the 'Agent' and 'Console' respectively. When properly setup, these plug-ins provide both local and remote real-time JSR77 compliant statistic monitoring, as well as historical tracking of any exposed statistic with visual representations drawn in the form of graphs through the Dojo Toolkit's dojoX Charting packages.
Agent (Server)
The Agent plug-in can be deployed headless on an instance of Geronimo requiring no administrative console able to be polled by the console plug-in from any instance of Geronimo that can communicate with it. There are two flavors of the Agent plug-in available; the first allowing for EJB connections, and the second allowing for JMX connections between the Console and Agent.
While the EJB Agent is the default plug-in installed with the full JEE5 assembly of Geronimo, the JMX is recommended for those that otherwise would require no form of EJB in their assembly but still require monitoring ability.
Console (Client)
Conversely, the console plug-in, which requires the Geronimo administrative console, can connect to multiple Agent plug-ins across multiple instances of Geronimo, allowing centralized monitoring of statistics on a multitude of machines. The same console is able to connect to either the EJB or the JMX flavor of the Agent plug-in, or even connect to both types on different instances of Geronimo.
What can I monitor?
From within the Agent plug-in in the administrative console, it is possible to define a connection to any instance of Geronimo that has the Monitoring Agent plug-in deployed. Furthermore, any MBean deployed on the Geronimo instance with the Monitoring Agent that provides statistics can be historically tracked, allowing for graph generation from any statistic element exactly as defined.
Standard behavior of the Monitoring Agent is to take snapshots of the JSR77 defined JVM statistics, as well as the web container statistics for the web container being used (either Jetty or Tomcat). Additional MBeans can be added, or these defaults can be easily removed through the Monitoring Console plug-in.
Currently available statistics:
- TransactionManager Statistics
- JVM Statistics
- AJP/Web/WebSSL Connector Statistics
- ThreadPool Statistics
- Web Application Statistics
Installation
There are two methods for installing the necessary Monitoring Plug-ins. The first (and easiest), is to log into the Geronimo administrative console for the instance of Geronimo onto which the plug-in(s) will be installed, and select 'Plugins' from the left navigation menu.
In the Plugins portlet:
- Click 'Update repository list'
- Select a valid Geronimo repository from the list available
- Click 'Show Plugins in selected repository'
- To install the Monitoring Agent, select the appropriate plug-in from the list shown
- If the OpenEJB component is not already present on the assembly, it may be beneficial to use the JMX flavor of the Monitoring Agent
- To install the Monitoring Console, select the plugin appropriate for the web container in use from the list shown
- If the goal is to both view and record statistics from the same instance of Geronimo, both the Agent and Console plugins must be installed
The second method is required if starting from a minimal assembly, or if the Geronimo administrative console is otherwise unavailable.
In terminal:
- Go to the Geronimo bin directory
- Execute:
java -jar deployer.jar search-plugins - At the prompt, enter the appropriate number(s) for the desired plugins
Customization
One of the primary goals in developing the monitoring and management plugin was to allow an administrator to monitor any Geronimo server. This meant that the customization must be easy.
DataSources
The datasources used to communicate to the DB on the server and client side are all packaged into separate plugins. By default, the provided datasources are used to connect an Apache Derby database (the reason for this is because the default DB that Geronimo uses is also Derby). However, since these datasources are packaged as plugins, anyone is able to write their own datasource deployment descriptor, package it into a plugin, and use it instead of the one provided by default.
Graphs
Administrators using the console are able to create customized graphs. They are able to specify which statistic to be on which axis, in addition to the ability to perform a mathematical operation on two statistics.
Views
Since there may be many different graphs, the concept of a "view" is used to bundle related graphs together for more manageable use. For example, all graphs related to a specific server can be bundled together, or all graphs graphing the throughput of servers.