Re: [rules-users] Problem with JPA session persistence in Drools Flow (5.0.1)

Kris, Thanks again. Sorry my earlier test case was missing some items. Updated test case provided below. Thanks Sanjay /*----------Start Test Case ------------*/ Updated Test Case:- a) Run org.drools.examples.process.order.OrderExample.java b) Click on the create button (with default options). Note :- Look up the the session id from the database c) From the eclipse plugin complete one human task (Verify Order). d) Stop the Order example . e) Update the method createWorkingMemory() in org.drools.examples.process.order.OrderExample.java, to load the last session id in the invocation of JPAKnowledgeService.loadStatefulKnowledgeSession. f) Run order Order example . Note:-Should see exception from loadStatefulKnowledgeSession. Was getting this error in H2 and Oracle. /*----------End Test Case ------------*/ SBalakrishnan wrote: > > Thanks for the quick response Kris and appreciate your help. > > It would be great if we can get more information on the activity by the > community member for the fail safe approach for the handlers. > > > Yes, I am using a modified > org.drools.examples.process.order.OrderExample.java class. > Using a modified drl file RuleSetExample.rf (Only two human tasks). > I am attaching the sample project. > > Thanks > Sanjay > > > > Test Case:- > > a) Run org.drools.examples.process.order.OrderExample.java > b) Click on the create button (with default options). > > > The main methods being called are:- > a) private void createWorkingMemory() > > intial setup and load of session happens here. > > b)createOrder() > > ksession.insert(),ksession.startProcess > > > > Kris Verlaenen wrote: >> >> That NPE seems to be an error in the marshaling of the session. Do you >> have a simple test case that you can send me so we can use that to >> reproduce this issue (I noticed you are extending the order example, but >> you seem to have introduced a few new classes and probably some rules as >> well)? >> >> Regarding the session marshaling, it persists its entire internal state. >> So that includes all running process instances, all data in the working >> memory (although that is configurable through a strategy) and the >> internal state (agenda etc.). This does not include the knowledge base >> or external components, like for example work item handlers. >> >> The current human task handler implementation does indeed not support >> restoring after failure, as the event listeners are not re-registered. >> A more fail-safe implementation, for example registering the necessary >> listeners upon initialization or using a fail-safe protocol like JMS >> should be used for that. If I remember correctly, a community member is >> already looking into that. >> >> Kris >> >> Quoting SBalakrishnan <Sanjay.Balakrishnan(a)fnis.com&gt;: >> >>> >>> Hi, >>> >>> >>> Looks like this issue and related problems >>> have become a show stopper for us. >>> >>> >>> >>> The UseCase we are trying to address is recreating inflight Human >>> Tasks >>> after the engine has been stopped (could be a shutdown or server >>> error scenario). >>> >>> It was noticed that if we do not insert any global variables in the >>> session >>> ,then we do not see the earlier reported Null pointer exception and >>> the >>> session load from >>> the previous session id goes through. >>> (Code snippet below) >>> >>> >>> But then I come to the next question, what type of information does >>> the >>> session >>> carry over (could not find information on it) . Is it only global >>> variables >>> ? >>> >>> >>> Also what happens to the informaton tied to the registered handlers. >>> In this case all the task event registrations in the human task >>> handler(CommandBasedWSHumanTaskHandler) >>> are lost.As a result it is noticed that it leads to tasks getting >>> completed >>> on the >>> MinaTaskServer, but the Process Flow not knowing about it and leading >>> to >>> workItems >>> remaining open (orphan items). >>> >>> Please do let us know if you have run into this issue or if you have >>> other inputs. >>> >>> >>> Thanks in advance >>> Sanjay >>> >>> /*Commented code to bypass first issue:-*/ >>> >>> Order order = new Order(); >>> order.setOrderId("Order-" + ++orderCounter); >>> order.setCustomerId(customerIdTextField.getText()); >>> ItemInfo itemInfo = (ItemInfo) itemComboBox.getSelectedItem(); >>> order.addOrderItem(itemInfo.getItemId(), new >>> Integer(amountTextField.getText()), itemInfo.getPrice()); >>> >>> AppData testAppData = new AppData(); >>> testAppData.setRelationShipPricing("Pricing"); >>> >>> //Commented global variable insert >>> //Commented ksession.insert(testAppData); >>> >>> Map<String, Object> parameters = new HashMap<String, Object>(); >>> parameters.put("order", order); >>> parameters.put("email", emailTextField.getText()); >>> WorkflowProcessInstance testProcess = (WorkflowProcessInstance) >>> ksession.startProcess("RuleSetExample", parameters); >>> ksession.fireAllRules(); >>> this._processId= testProcess.getId(); >>> >>> /*Commented code to bypass first issue:-*/ >>> >>> >>> SBalakrishnan wrote: >>> > >>> > Kris, >>> > >>> > Did download the artifacts (drools-5.1.0.SNAPSHOT-bin.zip) >>> > from the above location but ran into the same issue reported >>> earlier. >>> > >>> > >>> /*------------------------------------------------------------------*/ >>> > >>> > java.lang.RuntimeException: Unable to load session snapshot >>> > at >>> > >>> >> org.drools.persistence.session.JPASessionMarshallingHelper.loadSnapshot(JPASessionMarshallingHelper.java:112) >>> > at >>> > >>> >> org.drools.persistence.session.JPASessionMarshallingHelper.<init>(JPASessionMarshallingHelper.java:46) >>> > at >>> > >>> >> org.drools.persistence.session.SingleSessionCommandService.<init>(SingleSessionCommandService.java:194) >>> > at >>> > >>> >> org.drools.persistence.jpa.impl.JPAKnowledgeServiceProviderImpl.loadStatefulKnowledgeSession(JPAKnowledgeServiceProviderImpl.java:75) >>> > at >>> > >>> >> org.drools.persistence.jpa.JPAKnowledgeService.loadStatefulKnowledgeSession(JPAKnowledgeService.java:102) >>> > at >>> > >>> >> org.drools.examples.process.order.OrderExample.createWorkingMemory(OrderExample.java:279) >>> > at >>> > >>> >> org.drools.examples.process.order.OrderExample.<init>(OrderExample.java:107) >>> > at >>> > >>> org.drools.examples.process.order.OrderExample.main(OrderExample.java:88) >>> > Caused by: java.lang.NullPointerException >>> > at >>> > >>> >> org.drools.marshalling.impl.InputMarshaller.readLeftTuple(InputMarshaller.java:496) >>> > at >>> > >>> >> org.drools.marshalling.impl.InputMarshaller.readLeftTuples(InputMarshaller.java:426) >>> > at >>> > >>> >> org.drools.marshalling.impl.InputMarshaller.readFactHandles(InputMarshaller.java:349) >>> > at >>> > >>> >> org.drools.marshalling.impl.InputMarshaller.readSession(InputMarshaller.java:207) >>> > at >>> > >>> >> org.drools.marshalling.impl.DefaultMarshaller.unmarshall(DefaultMarshaller.java:75) >>> > at >>> > >>> >> org.drools.persistence.session.JPASessionMarshallingHelper.loadSnapshot(JPASessionMarshallingHelper.java:104) >>> > >>> > >>> /*------------------------------------------------------------------*/ >>> > >>> > >>> > I am creating a JPA session and starting a process >>> > with a human task and then stopping the engine without completing >>> > the human task .Then trying to load from the earlier session. >>> > >>> > Am I missing any calls before exit. >>> > >>> > Appreciate your help,thanks in advance >>> > >>> > Sanjay >>> > >>> > >>> > Kris Verlaenen wrote: >>> >> >>> >> We're planning to do a M1 near the end of the month, and a final a >>> few >>> >> weeks later. >>> >> >>> >> Kris >>> >> >>> >> Quoting SBalakrishnan <Sanjay.Balakrishnan(a)fnis.com&gt;: >>> >> >>> >>> >>> >>> Thanks Kris >>> >>> >>> >>> Will download from the below link and check. >>> >>> >>> >>> Quick question, do you know when the official 5.1 release will >>> be >>> >>> available >>> >>> ? >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> Kris Verlaenen wrote: >>> >>> > >>> >>> > The fix for this issue has been added to trunk about a month >>> ago >>> >>> already >>> >>> > I think, have you already tried with the 5.1.0 SNAPSHOT >>> release? >>> >>> Does >>> >>> > this solve your issue? >>> >>> > >>> >>> > You can get the snapshot at >>> >>> > >>> >>> >>> https://hudson.jboss.org/hudson/job/drools/lastSuccessfulBuild/artifact/ >>> >>> > >>> >>> > Kris >>> >>> > >>> >>> > Quoting SBalakrishnan <Sanjay.Balakrishnan(a)fnis.com&gt;: >>> >>> > >>> >>> >> >>> >>> >> Looks like I am running into the same/similar issue while >>> >>> recreating >>> >>> >> from a >>> >>> >> session_id. >>> >>> >> Exception pasted below. >>> >>> >> >>> >>> >> Any idea whether it will be addressed in the coming release ? >>> >>> >> >>> >>> >> >>> >>> >> Thanks in advance.. >>> >>> >> >>> >>> >> >>> >>> >> /*--------------------------------------------*/ >>> >>> >> >>> >>> >> Hibernate: select sessioninf0_.id as id0_0_, >>> sessioninf0_.dirty >>> >>> as >>> >>> >> dirty0_0_, sessioninf0_.lastModificationDate as >>> lastModi3_0_0_, >>> >>> >> sessioninf0_.rulesByteArray as rulesByt4_0_0_, >>> >>> sessioninf0_.startDate >>> >>> >> as >>> >>> >> startDate0_0_ from SessionInfo sessioninf0_ where >>> >>> sessioninf0_.id=? >>> >>> >> java.lang.RuntimeException: Unable to load session snapshot >>> >>> >> at >>> >>> >> >>> >>> > >>> >>> >>> >> >>> >> org.drools.persistence.session.JPASessionMarshallingHelper.loadSnapshot(JPASessionMarshallingHelper.java:112) >>> >>> >> at >>> >>> >> >>> >>> > >>> >>> >>> >> >>> >> org.drools.persistence.session.JPASessionMarshallingHelper.<init>(JPASessionMarshallingHelper.java:46) >>> >>> >> at >>> >>> >> >>> >>> > >>> >>> >>> >> >>> >> org.drools.persistence.session.SingleSessionCommandService.<init>(SingleSessionCommandService.java:171) >>> >>> >> at >>> >>> >> >>> >>> > >>> >>> >>> >> >>> >> org.drools.persistence.jpa.impl.JPAKnowledgeServiceProviderImpl.loadStatefulKnowledgeSession(JPAKnowledgeServiceProviderImpl.java:75) >>> >>> >> at >>> >>> >> >>> >>> > >>> >>> >>> >> >>> >> org.drools.persistence.jpa.JPAKnowledgeService.loadStatefulKnowledgeSession(JPAKnowledgeService.java:102) >>> >>> >> at >>> >>> >> >>> >>> > >>> >>> >>> >> >>> >> org.drools.examples.process.order.OrderExample.createWorkingMemory(OrderExample.java:257) >>> >>> >> at >>> >>> >> >>> >>> > >>> >>> >>> >> >>> >> org.drools.examples.process.order.OrderExample.<init>(OrderExample.java:99) >>> >>> >> at >>> >>> >> >>> >>> >>> org.drools.examples.process.order.OrderExample.main(OrderExample.java:80) >>> >>> >> Caused by: java.lang.NullPointerException >>> >>> >> at >>> >>> >> >>> >>> > >>> >>> >>> >> >>> >> org.drools.marshalling.impl.InputMarshaller.readLeftTuple(InputMarshaller.java:496) >>> >>> >> at >>> >>> >> >>> >>> > >>> >>> >>> >> >>> >> org.drools.marshalling.impl.InputMarshaller.readLeftTuples(InputMarshaller.java:426) >>> >>> >> at >>> >>> >> >>> >>> > >>> >>> >>> >> >>> >> org.drools.marshalling.impl.InputMarshaller.readFactHandles(InputMarshaller.java:349) >>> >>> >> at >>> >>> >> >>> >>> > >>> >>> >>> >> >>> >> org.drools.marshalling.impl.InputMarshaller.readSession(InputMarshaller.java:207) >>> >>> >> at >>> >>> >> >>> >>> > >>> >>> >>> >> >>> >> org.drools.marshalling.impl.DefaultMarshaller.unmarshall(DefaultMarshaller.java:75) >>> >>> >> at >>> >>> >> >>> >>> > >>> >>> >>> >> >>> >> org.drools.persistence.session.JPASessionMarshallingHelper.loadSnapshot(JPASessionMarshallingHelper.java:104) >>> >>> >> /*--------------------------------------------*/ >>> >>> >> >>> >>> >> >>> >>> >> Mauricio Salatino wrote: >>> >>> >> > >>> >>> >> > Ok, I will try to take a look at it.. this week.. >>> >>> >> > I will let you know if I can fix it >>> >>> >> > >>> >>> >> > 2009/7/28 DroolsUser <rafiuddin.mk(a)gmail.com&gt;: >>> >>> >> >> Mark / salaboy, I am also facing same problem while >>> recreate >>> >>> the >>> >>> >> session >>> >>> >> >> from database. Can you advice any alternative, so that I >>> can >>> >>> go >>> >>> >> forward >>> >>> >> >> till >>> >>> >> >> the next release. Moreover when is the new release is >>> ....... >>> >>> Do >>> >>> >> new >>> >>> >> >> release >>> >>> >> >> will targeting this kind problem? Please suggest any >>> >>> alternative >>> >>> >> to >>> >>> >> >> recreate >>> >>> >> >> the session from db. Thanks in advance...... >>> >>> >> >> >>> >>> >> >> gairey wrote: >>> >>> >> >> Mark, Done: https://jira.jboss.org/jira/browse/JBRULES-2199 >>> - >>> >>> >> thanks for >>> >>> >> >> the >>> >>> >> >> quick response. Regards, Alan Mark Proctor Sent by: >>> >>> >> >> rules-users-bounces(a)lists.jboss.org 08/07/2009 13:49 >>> Please >>> >>> >> respond to >>> >>> >> >> Rules >>> >>> >> >> Users List To Rules Users List cc Subject Re: >>> [rules-users] >>> >>> >> Problem with >>> >>> >> >> JPA >>> >>> >> >> session persistence in Drools Flow (5.0.1) Can you open a >>> JIRA >>> >>> for >>> >>> >> this, >>> >>> >> >> and >>> >>> >> >> we'll make sure it's done in the next few weeks: >>> >>> >> >> https://jira.jboss.org/jira/browse/JBRULES thanks Mark >>> >>> >> >> Alan.Gairey(a)tessella.com wrote: I'm currently using Drools >>> >>> Flow >>> >>> >> with JPA >>> >>> >> >> session persistence enabled as described in section 5.1 of >>> the >>> >>> >> User >>> >>> >> >> Guide. >>> >>> >> >> As a process executes, session information is saved to the >>> H2 >>> >>> >> database >>> >>> >> >> correctly. The problem comes if a process only executes >>> part >>> >>> way >>> >>> >> through, >>> >>> >> >> and I then try to finish the process by recreating a >>> session >>> >>> using >>> >>> >> the >>> >>> >> >> code: >>> >>> >> >> // recreate the session from database using the sessionId >>> >>> ksession >>> >>> >> = >>> >>> >> >> JPAKnowledgeService.loadStatefulKnowledgeSession( >>> sessionId, >>> >>> >> kbase, null, >>> >>> >> >> env ); This gives me a NullPointerException. Having looked >>> >>> into >>> >>> >> the >>> >>> >> >> Drools >>> >>> >> >> Flow source code, I think the problem is in the class >>> >>> >> >> >>> >>> >> >>> >>> > >>> >>> >>> >> >>> >> drools-persistence-jpa\src\main\java\org\drools\persistence\session\SingleSessionCommandService.java. >>> >>> >> >> The 4th constructor of this class is called as part of the >>> >>> loading >>> >>> >> of a >>> >>> >> >> knowledge session from the H2 database; this in turn leads >>> to >>> >>> the >>> >>> >> >> afterCompletion method of the inner class >>> SynchronizationImpl >>> >>> >> being >>> >>> >> >> called. >>> >>> >> >> The final two lines of this method are: >>> >>> >> ((JPAProcessInstanceManager) >>> >>> >> >> ((ReteooWorkingMemory) >>> >>> >> >> >>> session).getProcessInstanceManager()).clearProcessInstances(); >>> >>> >> >> ((JPAWorkItemManager) ((ReteooWorkingMemory) >>> >>> >> >> session).getWorkItemManager()).clearWorkItems(); However, >>> when >>> >>> >> called via >>> >>> >> >> the route described above, the session member variable of >>> >>> >> >> SingleSessionCommandService has not been set, thus causing >>> the >>> >>> >> >> NullPointerException. (Interestingly, running the unit >>> tests >>> >>> for >>> >>> >> >> drools-persistence-jpa does result in the >>> NullPointerException >>> >>> >> being >>> >>> >> >> thrown >>> >>> >> >> multiple times, although the tests are still listed as >>> having >>> >>> >> passed.) I >>> >>> >> >> believe enclosing the above two lines as follows will fix >>> the >>> >>> >> problem: if >>> >>> >> >> (session != null) { ((JPAProcessInstanceManager) >>> >>> >> ((ReteooWorkingMemory) >>> >>> >> >> >>> session).getProcessInstanceManager()).clearProcessInstances(); >>> >>> >> >> ((JPAWorkItemManager) ((ReteooWorkingMemory) >>> >>> >> >> session).getWorkItemManager()).clearWorkItems(); } Also, >>> in >>> >>> the >>> >>> >> 4th >>> >>> >> >> constructor of SingleSessionCommandService, after the >>> session >>> >>> has >>> >>> >> been >>> >>> >> >> set, >>> >>> >> >> the following line needs to be added to ensure the session >>> id >>> >>> is >>> >>> >> the same >>> >>> >> >> as >>> >>> >> >> the session info id: ((ReteooStatefulSession) >>> >>> >> this.session).setId( >>> >>> >> >> this.sessionInfo.getId() ); (This line is present at the >>> end >>> >>> of >>> >>> >> the 3rd >>> >>> >> >> constructor.) It would be great if this fix could make it >>> into >>> >>> the >>> >>> >> Drools >>> >>> >> >> 5.1 release. Thanks. >>> >>> >> _______________________________________________ >>> >>> >> >> rules-users mailing list rules-users(a)lists.jboss.org >>> >>> >> >> https://lists.jboss.org/mailman/listinfo/rules-users >>> >>> >> >> _______________________________________________ >>> rules-users >>> >>> >> mailing list >>> >>> >> >> rules-users(a)lists.jboss.org >>> >>> >> >> https://lists.jboss.org/mailman/listinfo/rules-users >>> >>> >> >> _______________________________________________ >>> rules-users >>> >>> >> mailing list >>> >>> >> >> rules-users(a)lists.jboss.org >>> >>> >> >> https://lists.jboss.org/mailman/listinfo/rules-users >>> >>> >> >> >>> >>> >> >> ________________________________ >>> >>> >> >> View this message in context: Re: Problem with JPA session >>> >>> >> persistence in >>> >>> >> >> Drools Flow (5.0.1) >>> >>> >> >> Sent from the drools - user mailing list archive at >>> >>> Nabble.com. >>> >>> >> >> >>> >>> >> >> _______________________________________________ >>> >>> >> >> rules-users mailing list >>> >>> >> >> rules-users(a)lists.jboss.org >>> >>> >> >> https://lists.jboss.org/mailman/listinfo/rules-users >>> >>> >> >> >>> >>> >> >> >>> >>> >> > >>> >>> >> > >>> >>> >> > >>> >>> >> > -- >>> >>> >> > - http://salaboy.wordpress.com >>> >>> >> > - http://www.jbug.com.ar >>> >>> >> > - Salatino "Salaboy" Mauricio - >>> >>> >> > _______________________________________________ >>> >>> >> > rules-users mailing list >>> >>> >> > rules-users(a)lists.jboss.org >>> >>> >> > https://lists.jboss.org/mailman/listinfo/rules-users >>> >>> >> > >>> >>> >> > >>> >>> >> >>> >>> >> -- >>> >>> >> View this message in context: >>> >>> >> >>> >>> > >>> >>> >>> >> >>> >> http://www.nabble.com/Problem-with-JPA-session-persistence-in-Drools-Flow... >>> >>> >> Sent from the drools - user mailing list archive at >>> Nabble.com. >>> >>> >> >>> >>> >> _______________________________________________ >>> >>> >> rules-users mailing list >>> >>> >> rules-users(a)lists.jboss.org >>> >>> >> https://lists.jboss.org/mailman/listinfo/rules-users >>> >>> >> >>> >>> > >>> >>> > >>> >>> > >>> >>> > >>> >>> > Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm >>> >>> > _______________________________________________ >>> >>> > rules-users mailing list >>> >>> > rules-users(a)lists.jboss.org >>> >>> > https://lists.jboss.org/mailman/listinfo/rules-users >>> >>> > >>> >>> > >>> >>> >>> >>> -- >>> >>> View this message in context: >>> >>> >>> >> >>> >> http://www.nabble.com/Problem-with-JPA-session-persistence-in-Drools-Flow... >>> >>> Sent from the drools - user mailing list archive at Nabble.com. >>> >>> >>> >>> _______________________________________________ >>> >>> rules-users mailing list >>> >>> rules-users(a)lists.jboss.org >>> >>> https://lists.jboss.org/mailman/listinfo/rules-users >>> >>> >>> >> >>> >> >>> >> >>> >> >>> >> Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm >>> >> _______________________________________________ >>> >> rules-users mailing list >>> >> rules-users(a)lists.jboss.org >>> >> https://lists.jboss.org/mailman/listinfo/rules-users >>> >> >>> >> >>> > >>> > >>> >>> -- >>> View this message in context: >>> >> http://www.nabble.com/Problem-with-JPA-session-persistence-in-Drools-Flow... >>> Sent from the drools - user mailing list archive at Nabble.com. >>> >>> _______________________________________________ >>> rules-users mailing list >>> rules-users(a)lists.jboss.org >>> https://lists.jboss.org/mailman/listinfo/rules-users >>> >> >> >> >> >> Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm >> _______________________________________________ >> rules-users mailing list >> rules-users(a)lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/rules-users >> >> > http://www.nabble.com/file/p25296442/SnapShotDroolsExample.zip > SnapShotDroolsExample.zip >