Hi, I am running into an issue in a highly concurrent environment where my threads are waiting on locking of the rule base when I try to insert into the session. I am wondering if an appropriate solution would be to create a pool of KnowledgeBase objects, each having its own rule base. A thread dump of my server had the message below for about 40 threads. For my use case, I create the knowledge base once, then don't modify it in any way. Thank you! Travis "ajp-bio-8010-exec-984" daemon prio=10 tid=0x081f3800 nid=0x2a7c waiting on condition [0x9f368000] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <0xf0489a50> (a java.util.concurrent.locks.ReentrantReadWriteLock$NonfairSync) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:186) at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:834) at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:867) at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1197) at java.util.concurrent.locks.ReentrantReadWriteLock$WriteLock.lock(ReentrantReadWriteLock.java:945) at org.drools.common.UpgradableReentrantReadWriteLock.lowPriorityWriteLock(UpgradableReentrantReadWriteLock.java:105) at org.drools.common.UpgradableReentrantReadWriteLock.writeLock(UpgradableReentrantReadWriteLock.java:88) at org.drools.common.AbstractRuleBase.lock(AbstractRuleBase.java:475) at org.drools.reteoo.builder.PatternBuilder.attachObjectTypeNode(PatternBuilder.java:276) at org.drools.reteoo.ClassObjectTypeConf.<init>(ClassObjectTypeConf.java:103) at org.drools.common.ObjectTypeConfigurationRegistry.getObjectTypeConf(ObjectTypeConfigurationRegistry.java:71) at org.drools.reteoo.Rete.assertObject(Rete.java:107) at org.drools.reteoo.ReteooRuleBase.assertObject(ReteooRuleBase.java:286) at org.drools.reteoo.ReteooWorkingMemory$WorkingMemoryReteAssertAction.execute(ReteooWorkingMemory.java:434) at org.drools.common.AbstractWorkingMemory.executeQueuedActions(AbstractWorkingMemory.java:993) at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:335) at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:311) at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:903) at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:847) at org.drools.impl.StatefulKnowledgeSessionImpl.insert(StatefulKnowledgeSessionImpl.java:269) -- View this message in context: http://drools.46999.n3.nabble.com/Pooling-KnowledgeBase-instances-tp40279... Sent from the Drools: User forum mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users