Welcome to the wiki landing page for Drools. This site is for the project Drools - for information about the product (sometimes known as JBoss Rules or BRMS platform) - see here. Drools is the upstream project of the BRMS platform (as well as feeding into other platforms). Please feel free to add your own tips/gotchas - you just need to sign-up for a jboss.org account (free and open to everyone).

Events and up to date info

Please read and subscribe to the the blog. Upcoming events and latest news appear there, as well as articles and much more.

Getting help from the community

For user questions, please use the user list. There is also an IRC channel. This is volunteer best effort support. For guaranteed/SLA support, please refer to the BRMS platform.

Pre-installed Development environment for Virtual Box

Details on the virtual box image can be found here.

SNAPSHOT Releases

We are now running the excellent Hudson build tool. Whenever a change is made, it will build. You can track it from https://hudson.jboss.org/hudson/job/drools/. To get the latest SNAPSHOT releases, go to https://hudson.jboss.org/hudson/job/drools/lastSuccessfulBuild/artifact/trunk/target/. After a commit, a new build is usually available 30-ish minutes later (if successful), depending on load/time of day etc.

NOTE: There is also a complete manual for JBoss Drools, this wiki supplements the formal manual (see below for links).

Important links

Online documentation

Testing framework add-on

JBoss Rules Student Projects

Reporting Issues and Errors

Internationalization (i18n)

Help in translations is always welcome. Guvnor (the web console) is available in various languages thanks to volunteers..

See: Helping out with Guvnor i18n (how to translate GUI).

Getting help and helping out

• As normal, the maniacs can be found in the drools IRC room at irc.codehaus.org. Web client available for those behind a firewall http://irc.codehaus.org. Mark Proctor is known as "conan", and he is a vegetarian, so he won't bite. The others are not though

• Use the mailing lists. Use the "user" list for end user issues, "dev" for when you are mucking about with the internals.

• Use jira to log issues.

Articles

• Real world rules by Geoffrey Wiseman

• Business Rules community A useful site especially for business rule analysis (your best buddies remember !)

• Embedding rules in your process

• Whats the big deal about the business rules approach

• O'Reilly Onjava - Give your business logic a framework with drools

• O'Reilly Onjava - Using Drools in Your Enterprise Java Application

• Cape Clear - exposing rules as a service

• Traffic control with rules

• Building enterprise services with drools

• Curtail logic complexity with rules

• Business rules and business processes - article on InfoQ explaining differences

• Solving planning problems: Introducing drools-solver (now known as drools-planner)

Samples

From the download page there are samples to show of various aspects. Some samples may be found on the wiki from time to time which are more up to date/richer.

Drools Puzzles - (A Regular Drools Programming Contest)

Since August 2007 we have a regular programming contest for JBoss-Drools. Initiated by E.Zhao, open to everyone. See the JBoss-Drools puzzle page for details. You might even win a price...

Standards

• Reverse user friendly and portable rule language (includes JBoss Rules translators)

Drools Research Network

Drools is used in a number of research projects in various universities, this page attempts to list some of these and provides details on the mailing list for academic collaborative efforts.

DroolsInAcademia

TIPS, TRICKS & FAQ for users (rule developers)

• DeployingGuvnor5OnWebSphere
• Deploying Guvnor on JBoss AS 5
• Clustering Guvnor (if you really really have to)Drools Guvnor 5.0 in JBoss AS 5

• Deploying BRMS (Business Rules Management WebApp) on non JBoss App Servers - example Weblogic and MySql

• Deploying BRMS on Tomcat 6, Jetty etc (some tweaks to libs are needed).

• DeployingBRMSOnOC4JTips

• Dynamically add a property change listener to your beans This means you don't need to "modify" object changes

• Intern strings for performance

• Don't be afraid of sync

• Function call in conditional part

• Serialization tips

• Tomcat (and JBoss AS) Issues and tricks - also applies to app servers that use tomcat or similar for JSP compilation

• Memory Issues - PermSpace and OutOfMemoryExceptions

• How to read/load things from your classpath

• Using the Reader interface to load drls from different sources

• Drools library in JBoss AS- NullPointerException at org.drools.compiler.PackageBuilder.compile(Unknown Source) using JBossAS 4.0.4GA

• Have problems with serialization? Then read this

• Counting facts from the LHS

• Finding maximum value and ordered processing

• JVM crashing

• Spring Framework Integration

• Agenda Timer Listener

• Comparing BigDecimal's in Rules

• How do I see the DRL for a Decision Table?

• What about an "else" statement?

• How do I fire a specific rule, or make sure only one rule in a group fires

• When to use rules, SQL, plain java or BPM

• Rules and BPM in a "process server"

• Weblogic and Jboss Rules integration

• Grandfather Rules

• WebSphere troubleshooting

• WhyMVEL

• NotFromMismatchedToken

• JBRMSV4.01150CreateEnumerationsViaDatabaseAccess

• JBRMSSmartEnumerations

• SolvingProblemsWhenWorkingWithXML

• RetrieveCompiledRulesSourceCode

• Solving performance problems related to accumulation

• Ant Task

   

• Eclipse plug-in Installation Instructions for Rational Application Developer v. 7.0: here

Rule patterns and practices

• Usage Patterns

Tips for JBoss Rules developers/contributors

• We have just moved to an ant driven build system (it uses maven 2 underneath, but you don't need to install maven yourself) due to complaints. See the manual for details on how to build.

• Building on Fedora Core linux

• Tips on merging between SVN branches

• SVN Best Practices

• How to do a Manual Release

• How to develop and maintain grammar tests

• How to upload artifacts to JBoss maven repo

Performance

• Benchmarks

Miscellaneous Questions

• What version of Rete (I, II or III) is Drools implementing?

Presentations (feel free to use as needed)

• Why use rules? Orlando BarCamp

• Why use rules? Why use drools?

  Many more, scan the blog for links to them.

   

Maven2 Repository

JBoss Rules is made available at the JBoss maven2 repository http://repository.jboss.com/maven2/ in the following directory http://repository.jboss.com/maven2/org/drools/. We do not currently upload to ibiblio, but community members are welcome.

Wiki guidelines

• Feel free to edit/add to this wiki - the aim of the wiki is not to be a manual, but to be a general "catch all" area for helpful tips and links. Also, articles and documentation may be entered here first, when its ready, it will then be formally moved into the manual for future reference. In the old Drools web site, the wiki was also the documentation, but for Drools 3 onwards, we are providing a formal manual for this purpose.

• Many tips are from real world deployments, add more of your own  Feedback/contributions are always appreciated. Its a wiki !

.Net version

• Information can still be located here

• Legacy drools.org site

Design and Enhancement ideas

This section is for contributors (of ideas and code) or people interested in the future directions of JBoss Rules. Some of these ideas are works well in progress, some are just concepts/thoughts. Jump in, the water is warm (its a wiki !).

BRMS (repository) designs

Rule Deployment Agent

DSLs, Natural Language and rules

SBVR standard (s beaver)

ReasoningOverDeepNestedObjectModels

ComplexEventProcessing

Event Stream Analysis

ObjectValidation

CertaintyFactors

BeyondORM

Backward  Chaining

LinearRuleEngine

LazyMultiListQueue

ImprovingRulesBuildPerformance

GuidedEditorImprovements

RuleTemplates

Decision tables:

DecisionTableTemplates