Cisco Systems 3.5 D Drools Rules Engine

Drools Rules Engine

Cisco Systems, Inc. Page 161

D Drools Rules Engine

About this appendix:

This appendix introduces and describes the Drools rules engine.

Drools Rules Engine Overview, below, introduces the Drools rules engine

components and terminology.

Drools and ANA Integration, page 162, explains how Drools is integrated

within Cisco ANA.

Drools Definitions in ANA, page 162, describes Drools within ANA.

Upgrading Rule Files, page 163, describes the rule upgrade process.

Drools rules engine is a general-purpose expert-system generator and

combines rule-based techniques and object-oriented programming. It also

provides a customizable mechanism to add decision support and data flow

control functions to business applications.

Drools rules engine is based on an object-oriented paradigm and uses user-

defined rules to perform pattern matching on different conditions. The rules

are written in a java like syntax, and are organized into source files (known as

a rule files), which are plain ASCII files.

Drools uses objects as marked out by patterns and rules that invoke certain

Actions:

• Drools objects are Java objects and can be represented by instances of

Java classes or XML schemas.

• A pattern is a coded expression (“program”), which manipulates one or

more objects to form a pattern to make, adapt or fashion behavior

according to designed logic.

• Working Memory is where Drools stores all the objects, which it is

currently handling.

• Actions are operations that may change the working memory.