Develop performance monitoring applications with the PMI client

A Performance Monitoring Infrastructure (PMI) client is an application that receives PMI data from servers and processes this data. Use the PMI client package to write PMI clients that collect and display PMI data from servers.

Clients can be graphical user interfaces (GUIs) that display performance data in real-time, applications that monitor performance data and trigger different events according to the current values of the data, or any other application that needs to receive and process performance data.

The programming model for PMI clients consists of these steps:

1. Create an instance of PmiClient. This instance is used for all subsequent method calls.
2. Call the listNodes() and listServers(nodeName) methods to find all of the nodes and servers in the WebSphere Application Server domain. The PMI client provides two sets of methods:
   • A set for Version 5
   • A set from Version 4>/li>

   Use only one set of methods.

3. Call listMBeans and listStatMembers to get all of the available MBeans and MBeanStatDescriptors.
4. Call the getStats method to get the Stats object for the PMI data.
5. (Optional) The client can also call setStatLevel or getStatLevel to set and get the monitoring level. Use the MBeanLevelSpec objects to set monitoring levels.

For the WebSphere Application Server Version 4 PMI interface, the object types are different. If you want to use the Version 4 interface, follow these steps:

1. Create an instance of PmiClient.
2. Call the listNodes() and listServers(nodeName) methods to find all of the nodes and servers in the WebSphere Application Server domain.
3. Call listMembers to get all of the perfDescriptor objects.
4. Use the PMI client's get or gets method to get CpdCollection objects. These objects contain performance data from the server. The same structure is maintained and its update method is used to refresh the data.
5. (Optional) The client can also call setInstrumentationLevel or getInstrumentationLevel to set and get the monitoring level.

See these topics for additional information about the PMI client package.

The PMI client package
This topic describes the WebSphere Application Server PMI client package.

The PMI client interface
The PMI client interface provides data in a hierarchical structure. This topic describes that structure.

Example: PMI client with new data structure
This topic provides an example of a PMI client that uses the new data structure.