The Common Base Event in WebSphere Application Server
The Common Base Event is an XML document that...
- Defines common fields
- Values they can take
- Meanings of these values
An application creates an event object whenever something happens that either needs to be recorded for later analysis, or which might require the trigger of additional work. An event is a structured notification that reports information that is related to a situation. An event reports three kinds of information:
- What happened
- The identity of the affected component. For example, the server that shut down
- The identity of the component that is reporting the situation, which might be the same as the affected component
The application that creates the event object is called the event source. Event sources can use a common structure for the event. The accepted standard for such a structure is called the Common Base Event. The Common Base Event is an XML document defined as part of the autonomic computing initiative.
The Common Base Event model is a standard that defines a common representation of events intended for use by enterprise management and business applications. This standard, which is developed by the IBM Autonomic Computing Architecture Board, supports encoding of logging, tracing, management, and business events using a common XML-based format. This format makes it possible to correlate different types of events that originate from different applications. The common event infrastructure currently supports Version 1.0.1 of the specification.
Avoid trouble:
For WebSphere Application Server v8.5, if we delete an application server that was previously deployed with the Common Event Infrastructure (CEI) enabled and you did not uninstall CEI before deleting the server, use a different name when creating an application server to deploy with CEI. If we deploy CEI on an application server that was created with the exact same server name as the server that was previously deleted and CEI was not uninstalled, the following error occurs:
com.ibm.websphere.management.exception.AdminException: ADMA5026E: No valid target is specified in ObjectName WebSphere:cell=targetCell,node=targetNode,server=targetServer for module EventServerMdb.jar+META-INF/ejb-jar.xml
If we did not uninstall CEI before deleting the application server, you must ensure that you use a name for the new application server that is different from the name of the server that was previously deployed with the common event infrastructure.
The basic concept behind the Common Base Event model is the situation. A situation can be anything that happens anywhere in the computing infrastructure, such as a server shutdown, a disk-drive failure, or a failed user login. The Common Base Event model defines a set of standard situation types that accommodate most of the situations that might arise (for example, StartSituation and CreateSituation).
The Common Base Event contains all of the information needed by the consumers to understand the event. This information includes data about the runtime environment, the business environment, and the instance of the application object that created the event.
For complete details on the Common Base Event format, see the XML schema included in the Common Base Event specification document, at http://www.ibm.com/developerworks/autonomic/books/fpy0mst.htm#HDRCBEDESC .
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