[rules-users] RE: [rules-dev] Multi threading usage best practice

Cross posted for information. Ths subject is more for the user list than the dev' one. Cheers, ________________________________ From: rules-dev-bounces(a)lists.jboss.org [mailto:rules-dev-bounces@lists.jboss.org] On Behalf Of 9Lives 9Lives Sent: 14 July 2008 14:33 To: Rules Dev List Subject: RE: [rules-dev] Multi threading usage best practice TnX Mike 4 the quick response. I'm afraid that u r right regarding the through-put ;-( Using the "synchronized" method will probably solve my problem but will damage the solution. If u have any other thoughts on the matter i would love 2 hear them. Regards Dotan ________________________________ Subject: RE: [rules-dev] Multi threading usage best practice Date: Mon, 14 Jul 2008 14:24:02 +0100 From: manstis1(a)ford.com To: rules-dev(a)lists.jboss.org Hi, Would synchronising on working memory effectively serialise the effects of fireAllRules()? ... synchronised(wm) { wm.fireAllRules(); } ... I don't know whether this would kill your through-put either. Cheers, Mike ________________________________ From: rules-dev-bounces(a)lists.jboss.org [mailto:rules-dev-bounces@lists.jboss.org] On Behalf Of 9Lives 9Lives Sent: 14 July 2008 13:41 To: rules-dev(a)lists.jboss.org Subject: [rules-dev] Multi threading usage best practice Hello I'm using Drools 4.0.7 inside a mail relay application 2 determine the operations that need 2 b executed on each passing message. To do this i'm using the following scenario: 1. I have a ruleBase.newStatefulSession(). 2. I have a fixed set of facts. 3. I have a fixed set of rules. 4. Each mailer (a thread that is handling a single message) is inserting the message to the working memory, calls the "fireAllRules" method and retracts the message. 5. Rules that r executed change custom attributes in the message. Problem: I noticed that sometimes a rule can b executed on the same message more then once. Assumption: My guess is that because i'm working is a multi threading environment but using a stateful session, what happens is: 1. Thread A is inserting Message A. 2. Thread B is inserting Message B 3. Thread A is calling fireAllRules 4. Rule X is executed on messages A + B. 5. Thread B is calling fireAllRules 6. Rule X is executed on messages A + B 7. Thread A is retracting Message A 8. Thread B is retracting message B Question: My goal is 2 make sure a rule is executed only once on a single message. Any ideas on how 2 avoid the situation described above? TnX Dotan ________________________________ Invite your mail contacts to join your friends list with Windows Live Spaces. It's easy! Try it! <http://spaces.live.com/spacesapi.aspx?wx_action=create&wx_url=/friends. aspx&mkt=en-us> ________________________________ Discover the new Windows Vista Learn more! <http://search.msn.com/results.aspx?q=windows+vista&mkt=en-US&form...