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>

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...

Did you synchronise on the insertion of objects into working memory too? (not as part of an activation on the RHS). What about the use of a stateless session per thread (isn't session creation really quick once the package\rulebase has been compiled)? In the mail relay below won't you want the set of rules to apply to one set of facts inserted by one thread representing one message? Is this achievable with a shared working memory? (Could you not get an activation caused by the presence of a fact inserted into working memory by one thread and the insertion into the same working memory of a fact by another thread). This is much more interesting that work ;-) Mike ________________________________ From: rules-dev-bounces(a)lists.jboss.org [mailto:rules-dev-bounces@lists.jboss.org] On Behalf Of Fenderbosch, Eric Sent: 14 July 2008 14:36 To: Rules Dev List Subject: RE: [rules-dev] Multi threading usage best practice We have multiple threads performing inserts/updates/queries/fireAllRules and had to synchronize access on working memory. The performance impact is surprisingly almost non-existent. ________________________________ From: rules-dev-bounces(a)lists.jboss.org [mailto:rules-dev-bounces@lists.jboss.org] On Behalf Of Anstis, Michael (M.) Sent: Monday, July 14, 2008 9:24 AM To: Rules Dev List Subject: RE: [rules-dev] Multi threading usage best practice 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>

Opsss. Sorry ... my mistake The phrase: "I did use sync on any reference ..." should b: "I did not use sync on any reference ..."Dotan From: ninelives35(a)hotmail.comTo: rules-dev(a)lists.jboss.orgSubject: RE: [rules-dev] Multi threading usage best practiceDate: Mon, 14 Jul 2008 17:53:59 +0300 I did use sync on any reference 2 the working memory with the hope of archiving the maximum performance from Drools.Stateless session seems like a waste of resources when thinking of the volume of messages passing through the server and translating that 2 create and destroy a session per each one.MayB i should rephrase my rules in some way that they would know if the message was already processed? Dotan Subject: RE: [rules-dev] Multi threading usage best practiceDate: Mon, 14 Jul 2008 14:51:49 +0100From: manstis1(a)ford.comTo: rules-dev(a)lists.jboss.org Did you synchronise on the insertion of objects into working memory too? (not as part of an activation on the RHS). What about the use of a stateless session per thread (isn't session creation really quick once the package\rulebase has been compiled)? In the mail relay below won't you want the set of rules to apply to one set of facts inserted by one thread representing one message? Is this achievable with a shared working memory? (Could you not get an activation caused by the presence of a fact inserted into working memory by one thread and the insertion into the same working memory of a fact by another thread). This is much more interesting that work ;-) Mike From: rules-dev-bounces(a)lists.jboss.org [mailto:rules-dev-bounces@lists.jboss.org] On Behalf Of Fenderbosch, EricSent: 14 July 2008 14:36To: Rules Dev ListSubject: RE: [rules-dev] Multi threading usage best practice We have multiple threads performing inserts/updates/queries/fireAllRules and had to synchronize access on working memory. The performance impact is surprisingly almost non-existent. From: rules-dev-bounces(a)lists.jboss.org [mailto:rules-dev-bounces@lists.jboss.org] On Behalf Of Anstis, Michael (M.)Sent: Monday, July 14, 2008 9:24 AMTo: Rules Dev ListSubject: RE: [rules-dev] Multi threading usage best practice 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 9LivesSent: 14 July 2008 13:41To: rules-dev(a)lists.jboss.orgSubject: [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: I have a ruleBase.newStatefulSession(). I have a fixed set of facts. I have a fixed set of rules. 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. 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: Thread A is inserting Message A. Thread B is inserting Message B Thread A is calling fireAllRules Rule X is executed on messages A + B. Thread B is calling fireAllRules Rule X is executed on messages A + B Thread A is retracting Message A Thread B is retracting message BQuestion: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? TnXDotan Invite your mail contacts to join your friends list with Windows Live Spaces. It's easy! Try it! Connect to the next generation of MSN Messenger Get it now! _________________________________________________________________ Invite your mail contacts to join your friends list with Windows Live Spaces. It's easy! http://spaces.live.com/spacesapi.aspx?wx_action=create&wx_url=/friend...