1. DROOLS ENABLED
MICROSERVICES
MAURICIO SALATINO
JBCNCONF 2016 - HANDS ON WORKSHOP

2. DROOLS ENABLED MICROSERVICES
INSTRUCTIONS
▸ Fork: http://github.com/salaboy/drools-game-engine/
▸ Clone your forked repository
▸ git clone http://github.com/<user>/drools-game-
engine/
▸ cd drools-game-engine/
▸ mvn clean install -DskipTests

3. DROOLS ENABLED MICROSERVICES
AGENDA
▸ What is Drools?
▸ Rule Language / Execution Cycle
▸ Drools & Microservices
▸ Scenario

4. DROOLS ENABLED MICROSERVICES
ABOUT ME
▸ Mauricio Salatino (aka Salaboy)
▸ Work for Red Hat
▸ Drools & jBPM Community
▸ http://salaboy.com
▸ @salaboy

5. DROOLS ENABLED MICROSERVICES
WHAT IS DROOLS?
▸ Lightweight Rule Engine (a library)
▸ Rule Engine -> Inference Engine
▸ Change of paradigm from Imperative (Java) to Declarative

6. DROOLS ENABLED MICROSERVICES
RULE STRUCTURE
▸ rule “Warn on low health”
//<rule attributes>
When
Player( health <= 10 )
Then
// Warning.. find medicine
end

7. DROOLS ENABLED MICROSERVICES
DROOLS ENGINE OVERVIEW (STATIC)

8. DROOLS ENABLED MICROSERVICES
DROOLS ENGINE OVERVIEW (RUNTIME)

9. DROOLS ENABLED MICROSERVICES
RULE EXECUTION CYCLE

10. DROOLS ENABLED MICROSERVICES
KIE APIS
▸ KieContainer
▸ KieBase
▸ KieSession
▸ insert(Object)
▸ retract(FactHandle)
▸ update(FactHandle, Object)
▸ fireAllRules() / fireAllRules(int)
▸ KieScanner
▸ kmodule.xml
DROOLS SPECIFICS

11. DROOLS ENABLED MICROSERVICES
MICROSERVICES KEY POINTS
▸ Bounded Context - Domain Driven Design
▸ Aligned with the company structure
▸ Small, managed by a team that knows about that
department requirements
▸ Using the right tool for the job ;)
▸ Release Fast - Release Early - Iterate

12. DROOLS ENABLED MICROSERVICES
DROOLS ENABLED MICROSERVICES
▸ Separate the business logic from technical aspects
▸ Use the bounded context model, no need to change anything,
leverage the scope
▸ Leverage the rule engine features (instead of creating in house
solutions to deal with logical checks and tricky scenarios)
▸ More flexible to business changes
▸ Self documented Micro Services
▸ Micro services that provides justification for each decision made out-of
the-box

13. DROOLS ENABLED MICROSERVICES
SCENARIO (GAME)

14. DROOLS ENABLED MICROSERVICES
SCENARIO (GAME)

15. DROOLS ENABLED MICROSERVICES
INSTRUCTIONS
▸ Fork: http://github.com/salaboy/drools-game-engine/
▸ Clone your forked repository
▸ git clone http://github.com/<user>/drools-game-
engine/
▸ cd drools-game-engine/
▸ mvn clean install -DskipTests

16. DROOLS ENABLED MICROSERVICES
RULES POWER
▸ Any Java Model (non-intrusive)
▸ Filter Data (Simple Filters)
▸ Correlate Data (Multiple filters between patterns)
▸ Accumulations / Aggregations (accumulate functions)
▸ Inference Chain
▸ Justification Log
▸ Query Data
▸ Truth Maintenance System(TMS)

17. GETTING STARTED WITH DROOLS
COMMUNITY
▸ www.drools.org / www.jbpm.org
▸ Drools & jBPM Mailing lists
▸ Report Bugs & Suggest Features: jira.jboss.org
▸ irc.freenode.net
▸ #drools
▸ #jbpm
▸ Blogs:
▸ blog.athico.com
▸ salaboy.com

18. QUESTIONS?
DROOLS ENABLED MICROSERVICES

19. GETTING STARTED WITH DROOLS
RETE

20. GETTING STARTED WITH DROOLS
PHREAK