[rules-users] Performance issue

[Wolfgang Laun]

The time for the first call isn't just for validating the DRL since
you do this *every* time you call check. There's lots of things a Java
program does "behind the scenes", i.e., without explicitly initiated
by the programmer.

Calling the Builder with a DRL source file to check a single bean is
extremely wasteful. Create the KnowledgeBase once and start sessions
from that. Also, consider serializing the KnowledgeBase and loading it
in separate runs (as described in the Expert manual).

Also consider using a Stateful Knowledge Session into which multiple
inserts are possible.

-W


On 31/05/2012, Ini <inder.14 at gmail.com> wrote:
> Hi All,
> 		I have written a code to check the properties of a bean using drools
> based
> rules.
> 		I have created the different rules file where different properties of the
> bean will be checked.
> 		
> 		The code i have written is a as below:
>
> public static void check(Object details,String rule){
> 		
> 		long methodStartTime=System.currentTimeMillis();
> 		Resource resource = new ClassPathResource(RULE_CLASSPATH+rule);
> 		
> 		KnowledgeBuilder kbuilder =
> KnowledgeBuilderFactory.newKnowledgeBuilder();
> 		long startTime=System.currentTimeMillis();
> 		kbuilder.add(resource, ResourceType.DRL );
> 		long endTime=System.currentTimeMillis();
> 		System.out.println("Time taken in add resource in milli seconds
> is::"+(endTime-startTime));
> 		 KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
> 			kbase.addKnowledgePackages( kbuilder.getKnowledgePackages() );
> 			 KnowledgeBuilderErrors errors = kbuilder.getErrors();
> 			 if (errors.size() > 0) {
> 				 for (KnowledgeBuilderError error: errors) {
> 					 System.err.println(error);
> 				 }
> 			 }
> 			
> 			 StatelessKnowledgeSession  ksession =
> kbase.newStatelessKnowledgeSession();
> 			 			
> 			
> 			 ksession.execute(details);
> 			 long methodEndTime=System.currentTimeMillis();
> 			
> 			 System.out.println("Time taken in Method check  in milli seconds
> is::"+(methodEndTime-methodStartTime));
> 			
> 	}
> 	
> 	Here in the check method we have three parameters details this is the bean
> whose properties need to be checked in rules file, rule this is the name of
> rules file which contains all the rules.
> 	
> 	Here the issue is that it takes around 4 seconds for the first time and 1
> second for all consecutive requests, and 4 second looks too much time for
> validating the rules file that has only 10 rules.
> 	
> 	Please let me know we have some better way of doing it in drools
>
> --
> View this message in context:
> http://drools.46999.n3.nabble.com/Performance-issue-tp4017688.html
> Sent from the Drools: User forum mailing list archive at Nabble.com.
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