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

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>