What do you monitor?

Service component monitoring is enabled on WebSphere Process Server by selecting certain points that a service component reaches during processing. This section explains how each service component defines these points, and the results of an invocation of a monitor on a service component when it detects some activity on a specific point.

Regardless of the type of monitoring you intend to perform on your service components (problem determination, performance tuning, or process monitoring), you will actually be monitoring a certain point that is reached during these components processing. This point is referred to as an event point, and it is these points that you select to be monitored. Each event point encapsulates the service component kind tag, an optional element kind (which are specific functions of a service component type), and the nature of the event. All of these factors will determine the type of event fired by monitoring.

Event natures describe the situations required to generate (or "fire") events during the processing of service components. These natures are essentially key points in the logic structure of a service component that you select to be monitored. The most common natures for service component events are ENTRY, EXIT, and FAILURE, but there are many other natures depending on the particular component and element. Whenever an application containing the specified service component is subsequently invoked, an event is fired every time the processing of a service component crosses the points corresponding to the event nature.

We will use the MAP service component as an example of how events are defined for a service component kind. The MAP service component kind can directly fire events with natures of ENTRY, EXIT, and FAILURE. It also includes an element kind, called Transformation, which defines a specific type of functionality within the MAP component kind. This element also fires events with ENTRY, EXIT, and FAILURE natures. Consequently, the MAP service component kind can fire up to six different events depending on the combination of elements and natures that you specify. The list of all service components, their elements, and their event natures is contained in the event catalog.

Monitoring is a separate layer of functionality that lies atop the processing of your applications, and does not interfere with the processing of your service components. Monitoring is concerned with service component processing only insofar as it detects activity at a specified event point. When this happens, an event is fired by monitoring, which determines where the event is sent, and what data is contained in that event, based on the type of monitoring you are performing, as detailed below:

Performance metrics
If you are monitoring a service component in order to gather performance metrics, light weight events are fired to the Performance Monitoring Infrastructure. You can select for monitoring one or more of the three performance statistics generated for process server-specific server components:
  • A counter for each EXIT event nature – this counts successful computations.
  • A counter for each FAILURE event nature – this counts failed computations
  • The processing duration calculated between corresponding ENTRY and EXIT events (synchronous computations only).
Common Base Events
If you wish to capture the data from events fired by monitoring at specified event points in service component, then you would configure the process server to generate the event and its data to be encoded in Common Base Event formats. Common Base Events capture the business data passed on invocations, responses, and possible failure points of any service request. You can choose to publish these events to either a logger or to the Common Event Infrastructure (CEI) bus, which directs the output to a specially configured CEI server database.
Related concepts
Monitoring performance
Monitoring Common Base Events
Event catalog

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Last updated: Thu Apr 27 14:31:35 2006

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