We've discovered that if we create a class in Java corresponding to our DerivedValues class, we do not get the error, however, this takes away the flexibility we were trying to provide our Guvnor users. Interestingly enough, if we put a print statement into the setter for appID in the Java class, we DO NOT see the print message until the 52 record. It appears that Drools does not start looking for the Class Definition until we've hit some sort of maximum limit of records in Guvnor. Is there some limit (number of instances, memory, etc.)? ------------------------------ Message: 5 Date: Tue, 24 Aug 2010 09:30:37 -0700 From: "John Peterson" <john.peterson.gv3k(a)statefarm.com&gt; Subject: [rules-users] NoClassDefFoundError when inserting Guvnor-declared Fact To: <rules-users(a)lists.jboss.org&gt; Message-ID: <D3A6E68928C9104BB815C83F43A36BDF0E27C9F1(a)WPSCV6NH.OPR.STATEFARM.ORG&gt; Content-Type: text/plain; charset="us-ascii" I'm experiencing a stack trace error (which I've pasted below) with a sample Drools/Guvnor application. I'm running version 5.0.1 right now. Here's the scenario: I have a Java application loading data (56 records right now) from a flat file, creating objects (one per row), parsing the individual fields on the file into the attributes of the objects, putting them into an array, and then inserting them into my Guvnor session. In Guvnor, I have a POJO model to receive the data plus a Declarative Model that enables the Guvnor user to set derived values based on the input data. There is a very basic rule that says the following (using the Guided Editor): When AppData[ad] Then System.out.println("Creating DerivedValues for " + ad.getAwards_id()); /* Added as Free Form DRL Insert DerivedValues appID=ad.getAwards_ID(); System.out.println("DerivedValus for Awards_id " + dv.getAwardsID()); /* Added as Free Form DRL Essentially, for each Fact of AppData, I'm creating and linking it to a Fact of DerivedValues that the user can add attributes to. I runs fine for the first 51 rows, then blows up on the rule when it is processing the 52 row (with 4 more to go after that). If I cut the file down to only have 51 rows, it doesn't blow up. The error - java.lang.NoClassDefFoundError: com/statefarm/DerivedValues is confusing because it has used DerivedValues 51 times without issue up to this point. I've been trying to a handle on this for a couple days without any luck. Here is my stack trace: RuleAgent(default) INFO (Tue Aug 24 11:17:12 CDT 2010): Configuring with newInstance=false, secondsToRefresh=-1 RuleAgent(default) INFO (Tue Aug 24 11:17:12 CDT 2010): Configuring package provider : URLScanner monitoring URLs: http://localhost:8080/drools-guvnor/org.drools.guvnor.Guvnor/package/com .statefarm/LATEST RuleAgent(default) INFO (Tue Aug 24 11:17:15 CDT 2010): Applying changes to the rulebase. RuleAgent(default) INFO (Tue Aug 24 11:17:16 CDT 2010): Adding package called com.statefarm (53 blank rows removed to save space) Creating DerivedValues for 122932 DerivedValus for Awards_id 122932 Creating DerivedValues for 122440 DerivedValus for Awards_id 122440 Creating DerivedValues for 122433 DerivedValus for Awards_id 122433 Creating DerivedValues for 122295 DerivedValus for Awards_id 122295 Creating DerivedValues for 119677 DerivedValus for Awards_id 119677 Creating DerivedValues for 118089 DerivedValus for Awards_id 118089 Creating DerivedValues for 118055 DerivedValus for Awards_id 118055 Creating DerivedValues for 118047 DerivedValus for Awards_id 118047 Creating DerivedValues for 118001 DerivedValus for Awards_id 118001 Creating DerivedValues for 117969 DerivedValus for Awards_id 117969 Creating DerivedValues for 117750 DerivedValus for Awards_id 117750 Creating DerivedValues for 117685 DerivedValus for Awards_id 117685 Creating DerivedValues for 117679 DerivedValus for Awards_id 117679 Creating DerivedValues for 117607 DerivedValus for Awards_id 117607 Creating DerivedValues for 117520 DerivedValus for Awards_id 117520 Creating DerivedValues for 117492 DerivedValus for Awards_id 117492 Creating DerivedValues for 117432 DerivedValus for Awards_id 117432 Creating DerivedValues for 117413 DerivedValus for Awards_id 117413 Creating DerivedValues for 117292 DerivedValus for Awards_id 117292 Creating DerivedValues for 117230 DerivedValus for Awards_id 117230 Creating DerivedValues for 117137 DerivedValus for Awards_id 117137 Creating DerivedValues for 116971 DerivedValus for Awards_id 116971 Creating DerivedValues for 116748 DerivedValus for Awards_id 116748 Creating DerivedValues for 116662 DerivedValus for Awards_id 116662 Creating DerivedValues for 116579 DerivedValus for Awards_id 116579 Creating DerivedValues for 116101 DerivedValus for Awards_id 116101 Creating DerivedValues for 115834 DerivedValus for Awards_id 115834 Creating DerivedValues for 115730 DerivedValus for Awards_id 115730 Creating DerivedValues for 114885 DerivedValus for Awards_id 114885 Creating DerivedValues for 114837 DerivedValus for Awards_id 114837 Creating DerivedValues for 114760 DerivedValus for Awards_id 114760 Creating DerivedValues for 114728 DerivedValus for Awards_id 114728 Creating DerivedValues for 114652 DerivedValus for Awards_id 114652 Creating DerivedValues for 114317 DerivedValus for Awards_id 114317 Creating DerivedValues for 113944 DerivedValus for Awards_id 113944 Creating DerivedValues for 113908 DerivedValus for Awards_id 113908 Creating DerivedValues for 113251 DerivedValus for Awards_id 113251 Creating DerivedValues for 113230 DerivedValus for Awards_id 113230 Creating DerivedValues for 112949 DerivedValus for Awards_id 112949 Creating DerivedValues for 112397 DerivedValus for Awards_id 112397 Creating DerivedValues for 111749 DerivedValus for Awards_id 111749 Creating DerivedValues for 111313 DerivedValus for Awards_id 111313 Creating DerivedValues for 111035 DerivedValus for Awards_id 111035 Creating DerivedValues for 110646 DerivedValus for Awards_id 110646 Creating DerivedValues for 110617 DerivedValus for Awards_id 110617 Creating DerivedValues for 109918 DerivedValus for Awards_id 109918 Creating DerivedValues for 109821 DerivedValus for Awards_id 109821 Creating DerivedValues for 109439 DerivedValus for Awards_id 109439 Creating DerivedValues for 109154 DerivedValus for Awards_id 109154 Creating DerivedValues for 105709 DerivedValus for Awards_id 105709 Creating DerivedValues for 105333 DerivedValus for Awards_id 105333 Creating DerivedValues for 103269 <- appears to blow up when creating/inserting the instance of DerivedValues Exception in thread "main" java.lang.NoClassDefFoundError: com/statefarm/DerivedValues at ASMAccessorImpl_320797751282666636960.getValue(Unknown Source) at org.mvel2.optimizers.dynamic.DynamicGetAccessor.optimize(DynamicGetAcces sor.java:87) at org.mvel2.optimizers.dynamic.DynamicGetAccessor.getValue(DynamicGetAcces sor.java:57) at org.mvel2.ast.NewObjectNode.getReducedValueAccelerated(NewObjectNode.jav a:170) at org.mvel2.compiler.ExecutableAccessor.getValue(ExecutableAccessor.java:3 7) at org.mvel2.ast.TypedVarNode.getReducedValueAccelerated(TypedVarNode.java: 68) at org.mvel2.MVELRuntime.execute(MVELRuntime.java:85) at org.mvel2.compiler.CompiledExpression.getValue(CompiledExpression.java:1 04) at org.mvel2.MVEL.executeExpression(MVEL.java:978) at org.drools.base.mvel.MVELConsequence.evaluate(MVELConsequence.java:87) at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:934) at org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:885) at org.drools.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1086) at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemo ry.java:660) at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemo ry.java:627) at com.statefarm.DroolsTest.main(DroolsTest.java:30) Caused by: java.lang.ClassNotFoundException: com.statefarm.DerivedValues at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClassInternal(Unknown Source) ... 16 more ********************************************