Intro to Drools - St Louis Gateway JUG
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The document discusses Drools and the JBoss Business Rules Management System (BRMS), including an overview of concepts like rules, facts, and the runtime execution environment. It also covers authoring rules with the guided rule editor in the web interface or with DRL, and integrating rules with Spring and Camel frameworks at runtime.
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Intro to Drools - St Louis Gateway JUG
- 1. Ray Ploski Director - Developer Experience Drools and the BRMS The Business Logic Integration Platform
- 2. Agenda • The Concepts • A Simple Example and Demo • Projects Overview • Best practices integrating Drools into your development process • Learning more, getting involved and getting support
- 3. What is Drools? Planner
- 5. What is JBoss BRMS? JBoss Enterprise BRMS BRMS • Single, integrated, certified distributions • Extensive Q/A Process • Industry-leading Support • Documentation • Secure, Production-level Configurations JBoss Runtime • Multi-year Errata Policy A common and complete platform to model and govern the business logic of the enterprise
- 6. JBoss Enterprise BRMS n Each JBoss Enterprise Middleware platform goes through a 5 phase delivery methodology that involves many traditional elements of the software development lifecyle: 1 2 3 4 5 Delivery Phase Drools Projects Product Platform Testing, Platform Release Platform Component Requirements Certification & (General Availability) Engineering & Integration Definition Documentation Platform Quality JBoss Candidate BRMS Enterprise Productization Team Assurance Release(s) BRMS JBoss QA, Documentation JBoss Release JBoss Product Team, Certified Partners Engineering Productization Management Engineers JBoss.org Engineers 6
- 7. The Concepts
- 8. The Typical SDLC View Layer Service Layer Business Layer Persistence Layer
- 9. The Typical SDLC View Layer Service Layer Business Layer Persistence Layer
- 10. The Typical SDLC View Layer Service Layer Business Layer Persistence Layer
- 11. The Typical SDLC View Layer Service Layer Business Layer Persistence Layer
- 12. The Typical SDLC View Layer Service Layer Business Layer Persistence Layer
- 13. The Typical SDLC View Layer Service Layer Business Layer Persistence Layer
- 14. The Typical SDLC View Layer Service Layer Business Layer Persistence Layer
- 16. Extract the Logic • Separate integration codebase from business logic and into a rules engine
- 17. Extract the Logic • Separate integration codebase from business logic and into a rules engine • Goal: Remove the requirements churn and complexity
- 18. Extract the Logic • Separate integration codebase from business logic and into a rules engine • Goal: Remove the requirements churn and complexity • Goal: Empower your Domain Experts to directly author rules
- 19. Business Logic
- 21. Business Logic • Rules • Process
- 22. Business Logic • Rules • Process • Response to Events
- 23. Business Logic • Rules • Process • Response to Events • Planning Problems
- 24. Why a Unified Approach? • Extend Rules Engine to handle process State • Extend the Engine to handle Events • Integration provides • Simplicity • Performance • Manageability • Integration of Features
- 25. What is a Rules Engine?
- 26. What is a Rules Engine? • Ambiguous Term
- 27. What is a Rules Engine? • Ambiguous Term • Inference Engine Concepts Clarify • Scales to a large number of rules and facts • Matches facts against rules to infer conclusions • Conclusions result in actions rule “XYZ” when <conditions> • Simple two-part structure: then <actions>
- 28. Facts • POJOs (Plain Old Java Objects) • Rules engine uses to evaluate conditions • Rules engine can execute POJO methods • Can be loaded from a database via Hibernate, JPA, etc... • Rules engine can modify a fact’s state • Dynamic Facts • Can be modeled in the Web UI
- 29. Facts • POJOs (Plain Old Java Objects) • Rules engine uses to evaluate conditions • Rules engine can execute POJO methods • Can be loaded from a database via Hibernate, JPA, etc... • Rules engine can modify a fact’s state • Dynamic Facts • Can be modeled in the Web UI
- 30. Fact Model Example public class Room { Model is multiple private String name // getter and setter methods here facts and their } relationships public class Sprinkler { private Room room; private boolean on; // getter and setter methods here } public class Fire { private Room room; // getter and setter methods here } public class Alarm { }
- 31. Fact Model Example public class Room { Model is multiple private String name // getter and setter methods here facts and their } relationships public class Sprinkler { private Room room; private boolean on; • Must have setters/ // getter and setter methods here getters } public class Fire { • Must have a public no-arg constructor private Room room; // getter and setter methods here • No mandatory } inheritance/ public class Alarm { interface }
- 32. Rules
- 33. Rules • Form the “IF/Then” action defined as “When/Then”
- 34. Rules • Form the “IF/Then” action defined as “When/Then” • Must have a name that is unique for a rule package
- 35. Rules • Form the “IF/Then” action defined as “When/Then” • Must have a name that is unique for a rule package • LHS (Left Hand Side) • Conditional part of the rule • Evaluate fact attributes based on criteria
- 36. Rules • Form the “IF/Then” action defined as “When/Then” • Must have a name that is unique for a rule package • LHS (Left Hand Side) • Conditional part of the rule • Evaluate fact attributes based on criteria • RHS (Right Hand Side) • Consequence or action part of the rule • Invoke operations • Modify Fact State
- 37. Rules • Form the “IF/Then” action defined as “When/Then” • Must have a name that is unique for a rule package • LHS (Left Hand Side) • Conditional part of the rule • Evaluate fact attributes based on criteria • RHS (Right Hand Side) • Consequence or action part of the rule • Invoke operations • Modify Fact State
- 38. Rules • Form the “IF/Then” action defined as “When/Then” • Must have a name that is unique for a rule package • LHS (Left Hand Side) • Conditional part of the rule • Evaluate fact attributes based on criteria • RHS (Right Hand Side) • Consequence or action part of the rule • Invoke operations • Modify Fact State
- 39. Rules • Form the “IF/Then” action defined as “When/Then” • Must have a name that is unique for a rule package • LHS (Left Hand Side) • Conditional part of the rule • Evaluate fact attributes based on criteria • RHS (Right Hand Side) • Consequence or action part of the rule • Invoke operations • Modify Fact State Rules can be authored in multiple ways!
- 40. Rules in DRL package com.sample import com.sample.*; rule "When there is a fire turn on the sprinkler" dialect "mvel" when Fire( $room: room) $sprinkler: Sprinkler( room == $room, on == false ) then modify ($sprinkler) {on = true}; println("Sprinkler activated in " + $room.name); end rule "When the fire is gone turn off the sprinkler" dialect "mvel" when $room : Room() $sprinkler : Sprinkler( room == $room, on == true ) not Fire( room == $room ) then modify( $sprinkler ) { on = false }; println( "Turn off the sprinkler for room " + $room.name ); end
- 41. Conditional Elements ● and ✓ all attributes match (default of comma separated list) ● or ✓ either attribute matches ● eval ✓ catch all element ✓ wraps any primative returning semantic code ● not ✓ attribute does not match ● exists ✓ checks for the existence of something ● collect, memberOf, accumulate ✓ elements to reason over collections of data ● from ✓ element to retreive data from external sources like DBs, WebServices, etc. ● matches, soundslike, ✓ regular expressions and English language phonetics
- 42. Rule Control ● no-loop ✓ short circuit rule recursion ● salience ✓ numeric value that represents rule importance ● agenda-group ✓ fire rules in group only when in focus ● auto-focus ✓ trigger focus change to the rule's agenda-group ● activation-group ✓ first matching rule fires ✓ all other rules in group are ignored lock-on-active ● date-effective, date-expires ✓ define rules that are only active at certain points in time ● template ✓ define templates that may be reused in multiple rules
- 43. Avenues for Authoring Rules - Dynamic Facts - Decision Tables - Guided Rules - English/Industry Specific Rules - Guided Tests - Scenario Tests - Asset Search - Browse by Category - Browse by Status Web Broswer - Spreadsheet Decision Tables Spread sheet - Technical Rules (.drl) - Enumerations - Domain Specific Language - Templates - Rule Flow - Step-debugging - Agenda Views and Inspection - Working Memory Inspection - Rule Engine Audit Trails - Technical Tests - Technical Test Suites JBoss Developer Studio
- 44. BRMS – Rich UI for Business Rules 20
- 45. Fact Model Editor 21
- 46. Guided Rule Editor (Web) 22
- 47. Web Decision Table Editor 23
- 48. Decision Tables 24
- 50. DroolsDoc
- 52. Multiple View / Edits in a Single Tab
- 53. From, Collect & Accumulate Support From CE From Collect CE From Accumulate CE
- 55. Working Sets
- 56. Fact Constraints within WorkingSets
- 57. Runtime
- 58. Runtime: Building private static KnowledgeBase readKnowledgeBase() throws Exception { KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(); kbuilder.add(ResourceFactory.newClassPathResource("fire.drl"), ResourceType.DRL); KnowledgeBuilderErrors errors = kbuilder.getErrors(); if (errors.size() > 0) { for (KnowledgeBuilderError error: errors) { System.err.println(error); } throw new IllegalArgumentException("Could not parse knowledge."); } KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase(); kbase.addKnowledgePackages(kbuilder.getKnowledgePackages()); return kbase; }
- 59. Runtime: Building private static KnowledgeBase readKnowledgeBase() throws Exception { KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(); kbuilder.add(ResourceFactory.newClassPathResource("fire.drl"), ResourceType.DRL); KnowledgeBuilderErrors errors = kbuilder.getErrors(); if (errors.size() > 0) { for (KnowledgeBuilderError error: errors) { System.err.println(error); } throw new IllegalArgumentException("Could not parse knowledge."); } KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase(); kbase.addKnowledgePackages(kbuilder.getKnowledgePackages()); return kbase; }
- 60. Runtime: Building private static KnowledgeBase readKnowledgeBase() throws Exception { KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(); kbuilder.add(ResourceFactory.newClassPathResource("fire.drl"), ResourceType.DRL); KnowledgeBuilderErrors errors = kbuilder.getErrors(); if (errors.size() > 0) { for (KnowledgeBuilderError error: errors) { System.err.println(error); } throw new IllegalArgumentException("Could not parse knowledge."); } KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase(); kbase.addKnowledgePackages(kbuilder.getKnowledgePackages()); return kbase; }
- 61. Runtime: Building private static KnowledgeBase readKnowledgeBase() throws Exception { KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(); kbuilder.add(ResourceFactory.newClassPathResource("fire.drl"), ResourceType.DRL); KnowledgeBuilderErrors errors = kbuilder.getErrors(); if (errors.size() > 0) { for (KnowledgeBuilderError error: errors) { System.err.println(error); } throw new IllegalArgumentException("Could not parse knowledge."); } KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase(); kbase.addKnowledgePackages(kbuilder.getKnowledgePackages()); return kbase; }
- 62. Runtime: Building private static KnowledgeBase readKnowledgeBase() throws Exception { KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(); kbuilder.add(ResourceFactory.newClassPathResource("fire.drl"), ResourceType.DRL); KnowledgeBuilderErrors errors = kbuilder.getErrors(); if (errors.size() > 0) { for (KnowledgeBuilderError error: errors) { System.err.println(error); } throw new IllegalArgumentException("Could not parse knowledge."); } KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase(); kbase.addKnowledgePackages(kbuilder.getKnowledgePackages()); return kbase; }
- 63. Camel & Spring Configuration <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:drools="http://drools.org/schema/drools-spring" http://drools.org/schema/drools-spring http://verylongurl/drools-spring-1.0.0.xsd> <drools:resource id="resource1" type="DRL" source="classpath:orgth:org/drools/container/spring/testSpring.drl"/> <drools:kbase id="kbase1"> <drools:resources> <drools:resource type="DRL" source="classpath:org/drools/container/spring/testSpring.drl"/> <drools:resource ref="resource1"/> <drools:resource source="classpath:org/drools/container/spring/IntegrationExampleTest.xls" type="DTABLE"> <drools:decisiontable-conf input-type="XLS" worksheet-name="Tables_2" /> </drools:resource> </drools:resources> <drools:configuration> <drools:mbeans enabled="true" /> <drools:event-processing-mode mode="STREAM" /> </drools:configuration> </drools:kbase> </beans> THE BRE now has extensive Spring support, the XSD can be found in the the drools-spring jar. The namespace is "http://drools.org/schema/drools-spring"
- 64. Runtime - Execution try { // load up the knowledge base KnowledgeBase kbase = readKnowledgeBase(); StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession(); KnowledgeRuntimeLogger logger = KnowledgeRuntimeLoggerFactory .newFileLogger(ksession, "test"); for( String name: ROOM_NAMES ){ Room room = new Room( name ); name2room.put( name, room ); ksession.insert( room ); Sprinkler sprinkler = new Sprinkler( room ); ksession.insert( sprinkler ); } // go ! ksession.fireAllRules();
- 65. Runtime - Execution try { // load up the knowledge base KnowledgeBase kbase = readKnowledgeBase(); StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession(); KnowledgeRuntimeLogger logger = KnowledgeRuntimeLoggerFactory .newFileLogger(ksession, "test"); for( String name: ROOM_NAMES ){ Room room = new Room( name ); name2room.put( name, room ); ksession.insert( room ); Sprinkler sprinkler = new Sprinkler( room ); ksession.insert( sprinkler ); } // go ! ksession.fireAllRules();
- 66. Runtime - Execution try { // load up the knowledge base KnowledgeBase kbase = readKnowledgeBase(); StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession(); KnowledgeRuntimeLogger logger = KnowledgeRuntimeLoggerFactory .newFileLogger(ksession, "test"); for( String name: ROOM_NAMES ){ Room room = new Room( name ); name2room.put( name, room ); ksession.insert( room ); Sprinkler sprinkler = new Sprinkler( room ); ksession.insert( sprinkler ); } // go ! ksession.fireAllRules();
- 67. Runtime - Execution try { // load up the knowledge base KnowledgeBase kbase = readKnowledgeBase(); StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession(); KnowledgeRuntimeLogger logger = KnowledgeRuntimeLoggerFactory .newFileLogger(ksession, "test"); for( String name: ROOM_NAMES ){ Room room = new Room( name ); name2room.put( name, room ); ksession.insert( room ); Sprinkler sprinkler = new Sprinkler( room ); ksession.insert( sprinkler ); } // go ! ksession.fireAllRules();
- 68. Runtime - Execution try { // load up the knowledge base KnowledgeBase kbase = readKnowledgeBase(); StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession(); KnowledgeRuntimeLogger logger = KnowledgeRuntimeLoggerFactory .newFileLogger(ksession, "test"); for( String name: ROOM_NAMES ){ Room room = new Room( name ); name2room.put( name, room ); ksession.insert( room ); Sprinkler sprinkler = new Sprinkler( room ); ksession.insert( sprinkler ); } // go ! ksession.fireAllRules();
- 69. Runtime - Execution try { // load up the knowledge base KnowledgeBase kbase = readKnowledgeBase(); StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession(); KnowledgeRuntimeLogger logger = KnowledgeRuntimeLoggerFactory .newFileLogger(ksession, "test"); for( String name: ROOM_NAMES ){ Room room = new Room( name ); name2room.put( name, room ); ksession.insert( room ); Sprinkler sprinkler = new Sprinkler( room ); ksession.insert( sprinkler ); } // go ! ksession.fireAllRules();
- 70. Runtime - Execution try { // load up the knowledge base KnowledgeBase kbase = readKnowledgeBase(); StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession(); KnowledgeRuntimeLogger logger = KnowledgeRuntimeLoggerFactory .newFileLogger(ksession, "test"); for( String name: ROOM_NAMES ){ Room room = new Room( name ); name2room.put( name, room ); ksession.insert( room ); Sprinkler sprinkler = new Sprinkler( room ); ksession.insert( sprinkler ); } // go ! ksession.fireAllRules(); > Everything is OK
- 71. Runtime - Execution Fire kitchenFire = new Fire( name2room.get( "kitchen" ) ); Fire officeFire = new Fire( name2room.get( "office" ) ); FactHandle kitchenFireHandle = ksession.insert( kitchenFire ); FactHandle officeFireHandle = ksession.insert( officeFire ); ksession.fireAllRules();
- 72. Runtime - Execution Fire kitchenFire = new Fire( name2room.get( "kitchen" ) ); Fire officeFire = new Fire( name2room.get( "office" ) ); FactHandle kitchenFireHandle = ksession.insert( kitchenFire ); FactHandle officeFireHandle = ksession.insert( officeFire ); ksession.fireAllRules(); > Raise the alarm > Turn on the sprinkler for room kitchen > Turn on the sprinkler for room office
- 73. Runtime - Execution ksession.retract( kitchenFireHandle ); ksession.retract( officeFireHandle ); ksession.fireAllRules();
- 74. Runtime - Execution ksession.retract( kitchenFireHandle ); ksession.retract( officeFireHandle ); ksession.fireAllRules(); > Turn off the sprinkler for room office > Turn off the sprinkler for room kitchen > Cancel the alarm > Everything is ok
- 75. Use FROM for external data rule “Find Vehicles for a given zip code" when $zipCode : ZipCode() Vehicle() from $hibernate.getNamedQuery( “FindVehicles” ) .setParameters( [ “zipCode” : $zipCode ]) .list() then ... end Can be a Web Service, Hibernate or any external system
- 76. Runtime Visibility - JMX • Drools 5.3 brings support to the JMX standard and enables knowledge base and knowledge session monitoring and inspection using any JMX console. KnowledgeBase Stats
- 77. Runtime Visibility - JMX KnowledgeSession Stats
- 78. Deployment - Packaging - Snapshots - Asset Search - Status Definition - Browse by Category - User Administration - Browse by Status - Categorization Analysis - Step-debugging - Agenda Views and Inspection - Rule Authoring Analysis - Working Memory Inspection - Guided Test Audit Trails - Rule Engine Audit Trails Tests - Technical Tests - Guided Tests - Technical Test Suites - Scenario Tests Rules - Technical Rules (.drl) - Decision Tables - Enumerations - Domain Specific Language - Decision Tables - Templates - Guided Rules - Rule Flow - English/Industry Specific Rules Facts Java Jars Dynamic Facts Developer-centric Business Analyst Web-only Feature Modifiable via Developer IDE Modifiable via Web Browser or Developer IDE Modifiable via Excel/OpenOffice
- 79. Deployment - Packaging - Snapshots - Asset Search - Status Definition - Browse by Category - User Administration - Browse by Status - Categorization Analysis - Step-debugging - Agenda Views and Inspection - Rule Authoring Analysis - Working Memory Inspection - Guided Test Audit Trails - Rule Engine Audit Trails Tests - Technical Tests - Guided Tests - Technical Test Suites - Scenario Tests Rules - Technical Rules (.drl) - Decision Tables - Enumerations - Domain Specific Language - Decision Tables - Templates - Guided Rules - Rule Flow - English/Industry Specific Rules Facts Java Jars Dynamic Facts Developer-centric Business Analyst Web-only Feature Modifiable via Developer IDE Modifiable via Web Browser or Developer IDE Modifiable via Excel/OpenOffice
- 80. Deployment - Packaging - Snapshots - Asset Search - Status Definition - Browse by Category - User Administration - Browse by Status - Categorization Analysis - Step-debugging - Agenda Views and Inspection - Rule Authoring Analysis - Working Memory Inspection - Guided Test Audit Trails - Rule Engine Audit Trails Tests - Technical Tests - Guided Tests - Technical Test Suites - Scenario Tests Rules - Technical Rules (.drl) - Decision Tables - Enumerations - Domain Specific Language - Decision Tables - Templates - Guided Rules - Rule Flow - English/Industry Specific Rules Facts Java Jars Dynamic Facts Developer-centric Business Analyst Web-only Feature Modifiable via Developer IDE Modifiable via Web Browser or Developer IDE Modifiable via Excel/OpenOffice
- 81. Eclipse – Developer Perspective 43
- 82. Debugging Debug Views l New rule “perspective” to configure IDE for rules as needed 44
- 83. Guided Rule Editor (Eclipse) Eclipse Guided Editor 45
- 84. Rule Flow 46
- 85. Node Types
- 86. Domain Specific Process Steps •Extend Drools Flow to incorporate your application’s needs Note: Community Only
- 88. CEP Complex event processing Real time events (concurrent events – thread safe): sliding windows: Pattern(...) over window:time(3000)
- 89. Fusion Enables: • Event Detection: • From an event cloud or set of streams, select all the meaningful events, and only them. • [Temporal] Event Correlation: • Ability to correlate events and facts declaring both temporal and non-temporal constraints between them. • Ability to reason over event aggregation • Event Abstraction: • Ability to compose complex events from atomic events AND reason over them
- 90. Events • (Usually) Immutable Facts • Strong Temporal Relationship • Managed Lifecylce • Use of sliding windows • Can provide metadata on: • @timestamp, @duration or @expires
- 91. Streams
- 92. Temporal Reasoning • Event and Time semantics: • Point in Time • Over an Interval • Unified semantics for event correlation over time • Temporal Constraints: • Set of 13 operators to express temporal relationship between events
- 93. Expressive Event Constraints Point-Point Point-Interval Interval-Interval A before B A meets B A overlaps B A includes B A finishes B A starts B A coincides B
- 94. Behaviors & Sliding Windows • Behaviors: special semantics to certain patterns • sliding windows, distinct, sort, etc • SlidingWindow: Allows reasoning over a moving window of “interest” • Time • Length
- 95. Memory Management •CEP scenarios are stateful by nature. •Events usually are only interesting during a short period of time. •Fusion manages the benefits memory management while events still in window of consideration
- 96. Rulebase Partitioning • Achieves coarse grained parallelization • No fundamental changes in the matching algorithm (ReteOO) • Preserves optimizations, especially node sharing
- 98. What is Planner? •Optimizes Automated Planning •Use Cases: • Space Planning • Employee Shift Rostering • Team Scheduling •Still in development! • Not commercially supported.
- 100. Patient Admission Schedule • Hard constraints • No 2 patients in same bed in same night • Room gender limitation • Department minimum or maximum age • Patient requires specific room equipment(s) • Soft constraints • Patient prefers maximum room size • Department specialization • Room specialization • Patient prefers specific room equipment(s)
- 101. Planner Syntax // If a hospital patient prefers specific equipment, try to assign him/her a hospital room with such equipment. rule "preferredPatientEquipment" when // If a patient prefers specific equipment PreferredPatientEquipment($patient : patient, $equipment : equipment); // and that patient is assigned a room BedDesignation(patient == $patient, $room : room); // and that room doesn't have that equipment not RoomEquipment(room == $room, equipment == $equipment); then ... // lower the score with a certain weight end
- 102. Needle in a Haystack
- 103. Needle in a Haystack • How many possible solutions? • 310 beds • in 105 rooms • in 4 departments • 84 nights
- 104. Needle in a Haystack • How many possible solutions? • 310 beds • in 105 rooms • in 4 departments • 84 nights • 2750 patients (admissions)
- 105. Needle in a Haystack • How many possible solutions? • 310 beds • in 105 rooms • in 4 departments • 84 nights • 2750 patients (admissions) • Numbers from a real dataset
- 106. Commercial Support •Drools ships within several supported platforms: • JBoss Enterprise BRMS • JBoss Enterprise SOA Platform * • JBoss Enterprise Application Platform **
- 107. Support Open Source! • We need You! • JBoss User Groups • Contribute • Code • Features • Documentation • Testing • Let us continue our work that benefits so many.