Hello, Me again and no it is not spamming, and I'm still drools newbie ;-) I was facing a problem of infinite loop with one of my rule, I have solved it but I'm wondering if my solution is not too costful on a performance point of view. So my question is really on the most efficient way of solving the infinite loop problem I'm gonna expose you right now. First of all, a few words the problem I want to solve with Drools : My company is a bank where traders are making deals on markets, these deals must be classified in book, this is what we call "booking process". Booking is done according to booking criteria : which trader has made the deal ? on which product ? etc ... A booking rule defines a set of criteria and the target book where the deal will classified. The guilty rule's job was to fill DealMatchingBookingRules with the booking rules applicable on a deal, (DealMatchingBookingRules references a unique deal). I have put below a corrected version by commenting the update($dealMatchingBookingRules) instruction of the RHS. With update uncommented, the problem occurred when 2 booking rule were matching the same deal in here's my understanding of the problem Facts inserted in the session : - dmbr1 (instance of DealMatchingBookingRule) referencing a deal - br1 and br2 matching the deal referenced in dmr1 Results : 1. rule is activated with (dmbr1, br1), dmbr1 is updated 2. rule is activated with (dmbr1, br2), dmbr1 is updated - (dmbr1, br1) does not activate the rule because of no-loop rule attribute 3. rule is activated AGAIN with (dmbr1, br1), dmbr1 is updated : back to step 1 4. rule is activated AGAIN with (dmbr1, br2), dmbr1 is updated : back to step 2 5. infinite loop on step1 & step 2 I have fixed the problem by removing the call to update, but for the next steps of my process (not shown here) Drools need to aware of the modified DealMatchingBookingRules. I thus have written a rule which only update all DealMatchingBookingRules. Is there a better way to solve this infinite loop ? Feel free to make comments, I'm really open to any suggestion/enhancement. Regards, Joël Costigliola rule "Find matching level 1 booking rules by deal" salience 10 no-loop ruleflow-group "Find level 1 matching booking rules by deal group" when $dealMatchingBookingRules : DealMatchingBookingRules($dealModel : deal, $dealProductRelatedIndexes : dealProductRelatedIndexes) $bookingRule : BTExecutionBookingRuleModel ( priority == 1 // when a criterion is not set, it is considered as satisfied. && (traderCriterion == null || $dealModel.trader == traderCriterion) && (portfolioCriterion == null || $dealModel.portfolio == portfolioCriterion) // when a product type criterion is set to unknown, it is considered as satisfied whatever deal product type is. && (productTypeStringCriterion == null || productTypeCriterion == ProductType.Unknown || $dealModel.product.productType == productTypeCriterion) && (listedIndexCriterion == null || $dealProductRelatedIndexes.relatedIndexes contains listedIndexCriterion) ) then $dealMatchingBookingRules.addMatchingBookingRule($bookingRule); // update($dealMatchingBookingRules) : COMMENTED BECAUSE WAS CAUSING INFINITE LOOP ! end // Does the job of update($dealMatchingBookingRules) but without INFINITE LOOP. rule "Refresh facts in level 1 booking rule process" salience 5 no-loop ruleflow-group "Refresh facts in level 1 booking rule process group" when $dealMatchingBookingRules : DealMatchingBookingRules() then update($dealMatchingBookingRules); end -------------------------------------------------------- Ce courriel et toutes les pièces jointes sont confidentiels et peuvent être couverts par un privilège ou une protection légale. 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