Performance Bottleneck on PackageClassLoader
Sushan Baskota
Dear community/drools team,
In my current project, compiled Collection<KiePackages> are stored as byte arrays and deserialized at runtime to convert them into KieBase objects. These KieBase instances are cached in-memory, and stateless KieSessions are created dynamically from them.
However, I’ve observed that the first execution of rules is significantly slow due to class loading overhead, specifically caused by a lock on PackageClassLoader. This has become a major bottleneck, especially since I’m dealing with thousands of unique rules that utilize similar fact objects. Each execution triggers class loading for the same set of classes, which is inefficient.
Approaches Tried So Far:- Pre-warming rules at startup: This helps reduce runtime latency but introduces a noticeable startup delay, which is problematic.
- Custom class loader implementation: Attempted to optimize class loading, but it doesn’t fully cover all dynamically generated classes.
Is there a recommended approach to avoid or minimize class loading during runtime in this scenario? Any strategies or best practices to preload or reuse class definitions efficiently would be greatly appreciated.
Sample code from my project:
On rule execution
// deserialized Kiepackages to get Kiebase
InternalKnowledgeBase kiebase = KnowledgeBaseFactory.newKnowledgeBase();
KieBasePackages kieBasePackages =(KieBasePackages) ois.readObject();
kiebase.addPackages(kieBasePackages.packages());
// get keisession from kiebase
StatelessKieSession statelessKieSession = kieBase.newStatelessKieSession();
//fire rule
statelessKieSession.execute(facts);
Thanks,
Alex Porcelli
Sounds like you could benefit from a more recent version with an
executable model.
> You received this message because you are subscribed to the Google Groups "Drools Usage" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to drools-usage...@googlegroups.com.
> To view this discussion visit https://groups.google.com/d/msgid/drools-usage/f02086a6-4991-42e2-b167-cf7b26bc4773n%40googlegroups.com.
Sushan Baskota
Alex Porcelli
outdated but also no longer maintained, which puts you in a difficult
position moving forward.