19.20. JBoss Rules

JBoss Rules is the name of the business rule engine provided as part of the Red Hat JBoss Fuse product.

The JBoss Rules engine is the computer program that applies rules and delivers Knowledge Representation and Reasoning (KRR) functionality to the developer.

A production rule is a two-part structure that uses first order logic to represent knowledge. It takes the following form:

when
    <conditions>
then
    <actions>

when
    <conditions>
then
    <actions>

The inference engine is the part of the BRMS engine which matches production facts and data to rules. It performs the actions based on what it infers from the information. A production rules system's inference engine is stateful and is responsible for truth maintenance.

The Rete implementation used in JBoss Rules is called ReteOO. It is an enhanced and optimized implementation of the Rete algorithm specifically for object-oriented systems. The Rete Algorithm has now been deprecated, and PHREAK is an enhancement of Rete. This section merely describes how the Rete Algorithm functions.

To learn how to use JBoss Rules, please refer to the BRMS Development Guide.