I am using Drools-Guvnor 5.1 release in an enterprise application. The rules created are separated per packages, and for each package there is a snapshot package called LATEST. The KnowledgeAgent polls the snapshot packages to get the latest data and load into the rule engine. Whenever there is a new rule, or updates to an existing one, the application triggers the process of re-creating the package snapshot: builds all the rules within the package, and creates a new snapshot for the package. The main problem with this approach is that the time to build the package rules, increases quite a lot as the number if rules gets higher. This creates a serious performance hit in the real-time app whenever there is a change to the rules. I sneaked a bit to the source code, and noticed that when build package is called, Guvnor builds a new binary for all the rules within a package even though not all of them are modified. Would it be possible to incrementally create/update the package binary? This would speed up things a lot when the package has lots of rules but only one rule changes at the time. What is the best approach for creating the package snapshots? The approach we've taken is to build all the rules within a package into one snapshot, and we ran into this performance issue. Any ideas/suggestions is much appreciated. Thanks, Patricia

Thanks David for your reply. To clarify: the performance problem is specifically related to the build package. This task takes longer as the package has more and more rules. The build package process is complex, and performs also rule validation. That's why I asked if there is a way to incrementally update the package binary. The app I am working on, we streamlined the process of creating a new rule, including building and deploying a new snapshot package to propagate the changes quick. Because the build task takes longer (as the package has more and more rules), it is a problem for the end user, as it feels that nothing happens for a while when saves a rule. Once the new snapshot package is created, the KnowledgeAgent propagates the updates into the app without problems. So, coming back to the build package task: what is the best strategy to create snapshot packages, so that the build time does not take a long time when there are lots of rules in the package?  One possible solution I see, is to create a snapshot package for each rule within a package, using a custom selector. I haven't tried it, but this approach will keep the build time short. However, it doesn't seem natural to me to have so many snapshot packages... thanks,Patricia  --- On Tue, 4/19/11, David Faulkner <david.faulkner(a)amentra.com&gt; wrote: From: David Faulkner <david.faulkner(a)amentra.com&gt; Subject: Re: [rules-users] Drools-Guvnor ­ question about build and deploy packages To: "Rules Users List" <rules-users(a)lists.jboss.org&gt; Date: Tuesday, April 19, 2011, 11:51 AM Patricia, My understanding (which is certainly open to being corrected) is that in general there is no way to do an incremental compilation of rules. The entire package is analyzed together and significant optimizations are performed to combine common items between rules (which is one of the big reasons why the engine executes so well!). So, generally, what you are doing is the "best practice".  When you say that you are experiencing a performance hit, are you talking about a delay in seeing the updates appear in your production application, or something else? Generally, the compilation is a one-time step, and even during compilation your enterprise application that is actually using the rules should continue to perform quite reasonably, since the compilation is going on in a separate application.  David From: Patricia Bogoevici <patriciabogoevici(a)yahoo.com&gt; Reply-To: Rules Users List <rules-users(a)lists.jboss.org&gt; Date: Tue, 19 Apr 2011 10:45:59 -0500 To: Rules Users List <rules-users(a)lists.jboss.org&gt; Subject: [rules-users] Drools-Guvnor – question about build and deploy packages I am using Drools-Guvnor 5.1 release in an enterprise application. The rules created are separated per packages, and for each package there is a snapshot package called LATEST. The KnowledgeAgent polls the snapshot packages to get the latest data and load into the rule engine. Whenever there is a new rule, or updates to an existing one, the application triggers the process of re-creating the package snapshot: builds all the rules within the package, and creates a new snapshot for the package. The main problem with this approach is that the time to build the package rules, increases quite a lot as the number if rules gets higher. This creates a serious performance hit in the real-time app whenever there is a change to the rules. I sneaked a bit to the source code, and noticed that when build package is called, Guvnor builds a new binary for all the rules within a package even though not all of them are modified. Would it be possible to incrementally create/update the package binary? This would speed up things a lot when the package has lots of rules but only one rule changes at the time. What is the best approach for creating the package snapshots? The approach we've taken is to build all the rules within a package into one snapshot, and we ran into this performance issue. Any ideas/suggestions is much appreciated. Thanks,Patricia -----Inline Attachment Follows----- _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

Thanks a lot Randhish!!! Stateful sessions will have to be disposed. But what if the sessions are taking too long, same with the case of stateless sessions, then what to do in that case. Also in the multi- threaded environment, if I have 10 - 100 Ks of threads, will the rule engines performance be still better. Thanks & Regards, Sumeet Karawal Mailto: sumeet.karawal(a)tcs.com From: Randhish Raghavan <Randhish_Raghavan(a)mindtree.com&gt; To: Rules Users List <rules-users(a)lists.jboss.org&gt; Date: 04/19/2011 08:51 PM Subject: Re: [rules-users] Fw: Some Querries on Drools Sent by: rules-users-bounces(a)lists.jboss.org Hi, I am quite new to drools but I will try to answer your questions. I don't think Drools will cause your application to crash if you ensure 1. You develop rules that will not result in infinite loops. 2. Dispose sessions if you are using Stateful sessions. Basically, you would want to create the Knowledge base once i.e. during application startup. You will create a new Session (not an expensive operation) for every request. In this scenario it will be better to use stateless sessions as you do not have to worry about disposing them. However, if you want to use statefull sessions, you might want to write a set of wrapper classes that provide api's to manage the statefull session and execute rules. Developers will only be allowed to access api's that execute rules and will not have access to api's that create and dispose a session. To you next question on making changes to rules, You have to create a KnowledgeAgent that checks if the rule resource has been modified at configured intervals. The rule resource (drl,pkg etc) can exist on the file system or you want to try to configure rules in guvnor. Guvnor is a GUI tool that allows you to manage rules. Regards, Randhish -----Original Message----- From: rules-users-bounces(a)lists.jboss.org [ mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Sumeet Karawal Sent: Tuesday, April 19, 2011 2:53 PM To: rules-users(a)lists.jboss.org Subject: [rules-users] Fw: Some Querries on Drools Hi Everybody, I had posted this earlier. It would be very greatful if anybody could help me on these queries, any suggestions or any document that I can refer to. Thanks and Regards, Sumeet Karawal Mailto: sumeet.karawal(a)tcs.com From: Sumeet Karawal/MUM/TCS To: rules-users(a)lists.jboss.org Date: 04/18/2011 06:58 PM Subject: Some Querries on Drools Hello All, I have some queries regarding use of drools as rule engine for my Application. It would be very helpful if I get some guidance regarding these: 1) I have an application in which a user logs in, and according to his profile he is provided with some benefits, and rule engine check for the eligibility criteria. But if hundreds of thousands of user will log in at same time, then what will be the performance accordingly. Like, these concurrent users hitting the server, and so many threads will be generated and many number of rules will be fired in the session. Will this hamper the performance of Rule Engine. 2) Suppose I have an application using drools. I create EAR / WAR file of that application and deploy it on some other system. Would it be still possible for me to change the rules on the fly. Or some dependencies might have to be managed. 3) How can we manage sessions in drools? Suppose we are having different stateful sessions in our application, but time consumption when we fireAllRules() exceeds the expected time. So is there a mechanism to kill, restart the session in drools. Could I get some help/document regarding session Management on drools. Thanks & Regards, Sumeet Karawal Mailto: sumeet.karawal(a)tcs.com =====-----=====-----===== Notice: The information contained in this e-mail message and/or attachments to it may contain confidential or privileged information. If you are not the intended recipient, any dissemination, use, review, distribution, printing or copying of the information contained in this e-mail message and/or attachments to it are strictly prohibited. If you have received this communication in error, please notify us by reply e-mail or telephone and immediately and permanently delete the message and any attachments. Thank you _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users ________________________________ http://www.mindtree.com/email/disclaimer.html _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users =====-----=====-----===== Notice: The information contained in this e-mail message and/or attachments to it may contain confidential or privileged information. If you are not the intended recipient, any dissemination, use, review, distribution, printing or copying of the information contained in this e-mail message and/or attachments to it are strictly prohibited. If you have received this communication in error, please notify us by reply e-mail or telephone and immediately and permanently delete the message and any attachments. Thank you