KnowledgeBaseOptionsConfiguration:

• <p>
• This class will automatically load default values from a number of places, accumulating properties from each location.
• This list of locations, in given priority is:
• System properties, home directory, working directory, META-INF/ of optionally provided classLoader
• META-INF/ of Thread.currentThread().getContextClassLoader() and META-INF/ of ClassLoader.getSystemClassLoader()
• </p>

Since this properties are only read when "RuleBaseConfiguration" ( KnowledgeBaseOptionsConfiguration implementor ) is constructed, this does not apply/work in case KnowledgeBase is defined via Spring without a <drools:configuration> due to the current sequence of events in "KnowledgeBaseDefinitionParser":

Element kbaseConf = DomUtils.getChildElementByTagName(element, "configuration");
if ( kbaseConf != null )

{ BeanDefinitionBuilder rbaseConfBuilder = BeanDefinitionBuilder.rootBeanDefinition( RuleBaseConfiguration.class ); // ... ... ... factory.addPropertyValue( "conf", rbaseConfBuilder.getBeanDefinition() ); }

To fix it, RuleBaseConfiguration ( which implements KnowledgeBaseOptionsConfiguration ) should be created even though "<drools:configuration>" was not provided ( kbaseConf == null ):

Element kbaseConf = DomUtils.getChildElementByTagName(element, "configuration");
BeanDefinitionBuilder rbaseConfBuilder = BeanDefinitionBuilder.rootBeanDefinition( RuleBaseConfiguration.class );
if ( kbaseConf != null )

{ // ... ... ... }

factory.addPropertyValue( "conf", rbaseConfBuilder.getBeanDefinition() );

Thank you,
/Anatoly