[ https://issues.jboss.org/browse/DROOLS-1687?page=com.atlassian.jira.plugi... ] Geoffrey De Smet commented on DROOLS-1687: ------------------------------------------ Mario and I had a meeting, we decided to *fail fast with a helpful error message (including accumulate name and hopefully rule name etc)* and Mario will create a new jira linked here to have *the min/max functions also have reverseSupport if and only if a flag is true on the KieSession*. Raw meeting notes: {code} A) return empty list // ge0ffrey: -1 (user doesn't know) B) log warning; return empty list C) Fail fast // ge0ffrey +1 throw UnsupportedOperationException "The justification failed because the accumulate function (max) in rule (my hard constraint) on line 72 in foo.drl does not have reverseSupport" D) minWithReverseSupport, maxWithReverseSupport con: users don't care and have to make a choice up front E) min and max have reverseSupport always con: performance loss? how much? F) Can we do E) with a flag on the KieBase? drools.setProperty("giveMinMaxReverseSupport" = true) G) Can we do E) with a flag on the KieSession? drools.setProperty("giveMinMaxReverseSupport" = true) // OptaPlanner knows for each KieSession if it needs justification or not (= constraintMatchEnabled = true) Proposal: C) in case they use a custom function without reverseSupport G) so C) doesn't happen much {code} -- This message was sent by Atlassian JIRA (v7.2.3#72005)