Release Notes

In order to make the kie-maven-plugin compatible with Maven-based project using a more recent version of the JDK, the plugin will now also look at the maven.compiler.release property to infer the language level to use during the build, with precedence over the java.version property (old behaviour).

When the kie-maven-plugin is used in a Maven-based project, we recommend NOT to set the drools.dialect.java.compiler.lnglevel in your KJAR project, so that the version of the JDK to be used is the one fully governed by the whole Maven build (including Java source files).

In order to generate the executable model with kie-maven-plugin, drools-model-compiler was required in prior versions, but starting from Drools 8.33, drools-engine or drools-ruleunits-engine dependency is enough to generate the executable model.

'with' statement is no longer supported in DRL. It should be easily rewritten with valid Java syntax.

Following the JDK Security Manager deprecation for removal in Java 17, since version 8.31.0.Final Drools no longer allows to define a Security Manager for constraints evaluation and consequences execution.

Rule Unit is a central paradigm in the Drools 8-series. You can refer the Migration guide chapter for more information about Rule Unit.

JDK 11 is now the minimum Java version required to compile Drools and make use of Drools.

Maven 3.8.6 is now the minimum Maven version required to build Drools from source, or using kie-ci APIs.

drools-mvel is now deprecated in favor of the executable model. It also means drools-engine is recommended instead of deprecated drools-engine-classic that contains drools-mvel. You can still use MVEL syntax in your rules, so it doesn’t affect how to write rules.

All the files with .xls, .xlsx and .csv extensions were considered and parsed as decision tables. In general, this was a too strong assumption, breaking projects containing random excel files that are not decision tables and generating artificial compile-time errors. To prevent such problems the filename extension policy has been changed, considering and processing files as decision tables only if their extension is prepended with .drl. In other words, only files with .drl.xls, .drl.xlsx, and .drl.csv extensions will now be compiled as decision tables. For example: rules.drl.xls is a valid extension and will be included for rule compilation when found in a KJAR based project.

The Drools features related to the JDK Security Manager will not be further developed, as starting with JDK17, the Java Platform has deprecated the Security Manager for removal. You can refer the Security Manager chapter for more information.

The KieMarshallers are still present and working as expected on the release of the Drools 8-series, however we are currently exploring alternative solutions more idiomatic to cloud-native use cases.

KIE Server is no longer a component of Drools 8. For migration, see Migration guide chapter.

Business Central is no longer a component of Drools 8. For migration, see Migration guide chapter.

Drools 8 no longer provides out of the box OSGi support in its modules.