We are trying to get a reproducer but this issue comes up intermittently in our systems.We are on drools 7.6.0 version. We see this crash when our service tries to update rules at runtime under heavy load. After that all requests start to fail . This issue is coming while inserting fact in session.
We have seen very similar logs mentioned in https://issues.jboss.org/browse/DROOLS-1383 in the thread dump on that instance.
The stack trace is seen below
java.lang.ArrayIndexOutOfBoundsException: 1 at org.drools.core.phreak.RuleNetworkEvaluator.innerEval(RuleNetworkEvaluator.java:349) ~[drools-core-7.6.0.Final.jar:7.6.0.Final] at org.drools.core.phreak.RuleNetworkEvaluator.outerEval(RuleNetworkEvaluator.java:169) ~[drools-core-7.6.0.Final.jar:7.6.0.Final] at org.drools.core.phreak.RuleNetworkEvaluator.evaluateNetwork(RuleNetworkEvaluator.java:127) ~[drools-core-7.6.0.Final.jar:7.6.0.Final] at org.drools.core.phreak.RuleExecutor.evaluateNetwork(RuleExecutor.java:71) ~[drools-core-7.6.0.Final.jar:7.6.0.Final] at org.drools.core.common.DefaultAgenda.evaluateEagerList(DefaultAgenda.java:887) ~[drools-core-7.6.0.Final.jar:7.6.0.Final] at org.drools.core.common.DefaultAgenda.fireLoop(DefaultAgenda.java:1061) ~[drools-core-7.6.0.Final.jar:7.6.0.Final] at org.drools.core.common.DefaultAgenda.internalFireAllRules(DefaultAgenda.java:1014) ~[drools-core-7.6.0.Final.jar:7.6.0.Final] at org.drools.core.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1006) ~[drools-core-7.6.0.Final.jar:7.6.0.Final] at org.drools.core.impl.StatefulKnowledgeSessionImpl.internalFireAllRules(StatefulKnowledgeSessionImpl.java:1318) ~[drools-core-7.6.0.Final.jar:7.6.0.Final] at org.drools.core.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:1309) ~[drools-core-7.6.0.Final.jar:7.6.0.Final] at org.drools.core.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:1293) ~[drools-core-7.6.0.Final.jar:7.6.0.Final]