Book Image

Mastering JBoss Drools 6

By : Mariano De Maio, Mauricio Salatino, Esteban Aliverti
Book Image

Mastering JBoss Drools 6

By: Mariano De Maio, Mauricio Salatino, Esteban Aliverti

Overview of this book

Mastering JBoss Drools 6 will provide you with the knowledge to develop applications involving complex scenarios. You will learn how to use KIE modules to create and execute Business Rules, and how the PHREAK algorithm internally works to drive the Rule Engine decisions. This book will also cover the relationship between Drools and jBPM, which allows you to enrich your applications by using Business Processes. You will be briefly introduced to the concept of complex event processing (Drools CEP) where you will learn how to aggregate and correlate your data based on temporal conditions. You will also learn how to define rules using domain-specific languages, such as spreadsheets, database entries, PMML, and more. Towards the end, this book will take you through the integration of Drools with the Spring and Camel frameworks for more complex applications.
Table of Contents (18 chapters)
Mastering JBoss Drools 6
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Preface
Index

Summary


This chapter served as an introduction to the underlying pattern matching algorithm used by Drools. An explanation on how the rules and their internal patterns and constraints are decomposed into a network of nodes was provided. Some important tips on how to improve the performance of our KIE Bases was also included.

This chapter also covered a major topic in Drools: backward-chaining. We saw how, using queries, we can construct knowledge that follows the backward reasoning concept: start from a goal and try to fulfill it. The hybrid approach between forward and backward reasoning that Drools takes gives us a powerful and very expressive way to define our knowledge.

The main differences between RETEOO (the algorithm used in previous versions of Drools) and PHREAK were also explained in this chapter. Features such as delayed rule evaluation, set-oriented propagation, and network segmentation, not only make PHREAK a more efficient algorithm, but also facilitate real parallel evaluation...