TIBCO BusinessEvents creates instances of simple events and time events based on user-configured event definitions. The following sections provide more detail on each type of event.
A simple event definition is a set of properties related to a given activity. It includes information for evaluation by rules, meta-data that provides context, and a separate payload—a set of data relevant to the activity.
For example, suppose you are interested in monitoring the creation of new employee records. You might create a simple event definition that includes important fields from the employee record, perhaps the social security number, department, and salary. You could then write a rule to create an instance of this simple event each time a new employee record is created.
A simple event is an instance of a simple event definition. It is a record of a single activity that occurred at a single point in time.
Just as you cannot change the fact that a given activity occurred, once an event is asserted into the Rete network, you can no longer change it. (Before assertion you can use an event preprocessor to enrich the event, however.) Simple events expire when their time to live has elapsed, unless TIBCO BusinessEvents has instructions to consume them prior to that time.
Example 1: A temperature sensor records a reading that is above a predefined limit. The payload might include the temperature-sensor ID, the reading, and the date and time. This simple event might trigger a complex event that would immediately notify a manager.
Example 2: A customer purchases four airline tickets from San Francisco, California to San Jose, Costa Rica. The payload might include the date and time of purchase, the date and time of the flight, the purchase price, the credit card number, the flight number, the names of the four passengers, and the seat assignments. This simple event alone may include no exceptions. However, it is possible that when examined within the context of other related events, an exception may arise. For example, one or more of the passengers may have booked tickets on another flight during the same time period.
Advisory events are asserted into the Rete network automatically when certain conditions, for example, exceptions, occur. Add the AdvisoryEvent event type to rules to be notified of such conditions. An advisory event expires after the completion of the first RTC cycle (that is, the time to live code is set internally to zero). The types of advisory events are described next.
Exception The TIBCO BusinessEvents engine automatically asserts an advisory event when it catches an exception that originates in user code but that is not caught with the
catch command of the TIBCO BusinessEvents Exception type. (For information on working with exceptions, see
Exception Handling in
TIBCO BusinessEvents Developer’s Guide.)
TIBCO BusinessEvents–ActiveMatrix BusinessWorks Integration Advisory events are also used in the container mode TIBCO BusinessEvents-ActiveMatrix BusinessWorks integration feature
invokeProcess() function. Such events are asserted when the ActiveMatrix BusinessWorks process fails or times out (or is cancelled).
Engine-Activated Advisory Event An advisory event is asserted when an engine has finished starting up and executing startup functions (if any).