Rule Priority and Rank

For each RTC, the rule agenda is sorted by priority and then within priority by rank, for those rules that use the same ranking mechanism.

Use of priority and rank is optional. You can also use priority without using rank.

TIBCO recommends that you use priority and rank features only as needed; that is, unless there is reason to set priority (or priority and rank), let the rule engine determine the sequence of execution. This lessens the complexity of rule maintenance, and takes advantage of the power of the inferencing engine.

Rule Priority
Because TIBCO BusinessEvents rules are declarative rather than procedural, there is no inherent order for processing. However, a priority property allows you to specify the order in which rules in one RTC execute.
Rule Rank Within the Same Priority
If you want to also control the order in which rules with the same priority execute, you can use the rule rank feature. The value for the Rank property is a rule function that returns a double. The larger the return value, the higher the ranking. You can specify the same rule function in different rules to perform ranking across tuples of those rules.
Other Rules
Not all rules in TIBCO BusinessEvents are inferencing rules. Rules in decision tables are business rules, executed only when the table is invoked.

Form-based and Source Rule Editors

When you work with rules and rule functions, you can choose how to work:

  • Using a form-based rule editor, similar to the rule editor in earlier versions of TIBCO BusinessEvents
  • Using a source editor, which is closer to a Java programming environment.

You can switch between editors and changes made in one editor are reflected in the other one. You cannot switch from the source editor to the form editor if there are validation errors in the code.

Effect of Cache Only Cache Mode

When using Cache Only cache mode for one or more entities, you must consider how to handle the cache-only entities when you write rules and preprocessor rule functions. See Working With Cache Modes and Loading Cache Only Objects into the Rete Network in TIBCO BusinessEvents Architect’s Guide.