Bug 724237 (BRMS-181)

Summary:	StatelessKnowledgeSessions created by KnowledgeAgent causes NullPointerException when used in a pipeline
Product:	[JBoss] JBoss Enterprise BRMS Platform 5	Reporter:	nwallace <nwallace>
Component:	unspecified	Assignee:	Mark Proctor <mark.proctor>
Status:	CLOSED NEXTRELEASE	QA Contact:
Severity:	unspecified	Docs Contact:
Priority:	high
Version:	unspecified
Target Milestone:	---
Target Release:	5.0.1
Hardware:	Unspecified
OS:	Unspecified
URL:	http://jira.jboss.org/jira/browse/BRMS-181
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:	5.0.1.SNAPSHOT for May 12, 2009
Last Closed:	2009-09-01 12:29:19 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:

Description nwallace 2009-07-07 15:28:28 UTC

Date of First Response: 2009-09-10 01:37:38
securitylevel_name: Public

This issue is related to this thread on the user-list:  http://www.mail-archive.com/rules-users@lists.jboss.org/msg08770.html

I'm getting a NullPointerException when I insert an object into
the pipeline using 5.0.1.SNAPSHOT from May 12, 2009:
java.lang.NullPointerException
        at 
org.drools.runtime.pipeline.impl.StatelessKnowledgeSessionPipelineImpl.insert(StatelessKnowledgeSessionPipelineImpl.java:24)

It looks like StatelessKnowledgeSession's ruleBase is null when created by the KnowledgeAgent, which poses a problem since StatelessKnowledgeSessionPipelineImpl invokes getRootClassLoader() on the session's ruleBase.

Here's what I'm doing:
StatelessKnowledgeSession ksession = kagent.newStatelessKnowledgeSession();
Pipeline pipeline =
PipelineFactory.newStatelessKnowledgeSessionPipeline(ksession);
pipeline.setReceiver(messageTransformer);
pipeline.insert(message);  // NPE here

I'll attach a patch to KnowledgeAgentTest containing a failing test case.

Comment 1 nwallace 2009-07-07 15:29:50 UTC

Link: Added: This issue is related to JBRULES-2090

Comment 2 nwallace 2009-09-01 12:29:19 UTC

Fix in place.

Comment 3 David Le Sage 2009-09-10 05:37:38 UTC

For documenting this in the Release Notes, can you please confirm the following and fill in the missing information. Dot point explanations are fine:

The CAUSE (what was actually broken)
 * 

CONSEQUENCES of the bug (how it impacts users.)
 * The StatelessKnowledgeSessions created by the Knowledge Agent were, when used in pipelines, causing  null pointer exceptions. 

The FIX (what was changed to eliminate this bug) and 
 * The Agent is now checked to ensure that the latest version of the rulebase has been set.

RESULTS of the fix (what now happens for users.)
 *

Comment 4 Dana Mison 2009-10-05 05:45:07 UTC

added to the 5.0.CP01 release notes as resolved:

JBRULES-2090
StatelessKnowledgeSessions created by KnowledgeAgent could throw a Null Pointer Exception if used in a pipeline. This because KnowledgeAgent creates the StatelessKnowlegeSession with a null ruleBase. The Agent is now checked to ensure that the latest version of the rule base has been set.