Rule Flows with Drools 10
Supporting the Classic Drools API in Apache KIE¶
Apache KIE continues to support the classic Drools API, ensuring a smooth migration path for users upgrading from earlier versions. This includes the traditional approach of creating a KieSession, inserting facts, and firing rules:
KieSession session = kbase.newKieSession();
session.insert(obj1);
// ...
session.insert(objN);
session.fireAllRules();
This method remains fully supported in the community edition, facilitating straightforward transitions for existing applications.
Limitations in Community Edition: Rule Flows and startProcess¶
While the classic API is supported, certain features like rule flows initiated via the startProcess method are not available in the community edition. For example:
KieSession session = kbase.newKieSession();
session.insert(obj1);
// ...
session.insert(objN);
session.startProcess("RuleOrchestrationProcess");
session.fireAllRules();
startProcess is an exclusive Aletyx feature in Aletyx Enterprise Build of Kogito and Drools
The startProcess method is not supported in the community edition due to architectural shifts favoring more modern, code-centric approaches. This is currently supported by Aletyx to help a quicker adoption to move to Drools 10.
Recommended Alternative: Rule Units¶
For users requiring process orchestration, adopting Rule Units is the recommended approach. Rule Units provide a modular and declarative way to define and execute rules, aligning with contemporary development practices. They allow for better integration with modern frameworks and support more maintainable and testable code structures.
Aletyx Enterprise Support for startProcess¶
We understand that migrating to Rule Units takes time, especially for enterprise users with large and mature rule sets. To support this transition, Aletyx Enterprise provides continued support for the startProcess API as a temporary solution. This helps teams maintain their existing workflows while planning for longer-term updates.
This support is available only when your project is packaged as a KJAR. This does not mean you need to use KIE Server. Instead, the KJAR acts as a regular dependency in your application, most commonly in Spring Boot (which is fully tested) and optionally in Quarkus (which has limited testing).
You can run these applications as containers, including in environments such as Docker or different flavors of Kubernetes.
To enable this support, you also need to make a minor adjustment to your BPMN process. You must add a metadata attribute:
- Name:
LegacyRuleFlow - Value:
true
This instructs the system to use the legacy flow integration for the process. If this metadata is missing, you may encounter the following error during runtime:
While this approach helps meet immediate needs, we encourage migrating to Rule Units as part of your long-term plan. Rule Units offer a more modern, robust, and maintainable approach to business rule execution.
Assistance for Migration¶
If you are planning to upgrade to Drools 10.x and currently utilize rule flows, Aletyx's team of experts is available to assist with the migration process. Our goal is to ensure a seamless transition, minimizing disruptions and aligning your applications with the latest best practices in rule management.
For more information and support, please visit https://aletyx.ai/contact-us to reach out!
