6:04 a.m.
Stefan Krause [http://community.jboss.org/people/krausest] created the discussion
"How to persist a timer"
To view the discussion, visit: http://community.jboss.org/message/629101#629101
--------------------------------------------------------------
I'm failing miserably at persisting a process with a timer.
I'm disposing the session before the timer expires. When I call
JPAKnowledgeService.loadStatefulKnowledgeSession with the old session id I'm getting
an exception. I've attached a test case with a simple maven project. Just use mvn test
to see the issue.
Any help would be appreciated.
java.lang.IllegalStateException: java.lang.reflect.InvocationTargetException
at
org.drools.persistence.jpa.KnowledgeStoreServiceImpl.buildCommanService(KnowledgeStoreServiceImpl.java:101)
at
org.drools.persistence.jpa.KnowledgeStoreServiceImpl.loadStatefulKnowledgeSession(KnowledgeStoreServiceImpl.java:69)
at
org.drools.persistence.jpa.JPAKnowledgeService.loadStatefulKnowledgeSession(JPAKnowledgeService.java:131)
at net.stefankrause.jbpm.ProcessRunner.setupSession(ProcessRunner.java:94)
at net.stefankrause.jbpm.ProcessRunner.<init>(ProcessRunner.java:49)
at
net.stefankrause.jbpm.tests.TimerPersistence.testTimerPersistence(TimerPersistence.java:34)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at
org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
at
org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at
org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at
org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at
org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)
at
org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)
at
org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
at
org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:49)
at
org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at
org.drools.persistence.jpa.KnowledgeStoreServiceImpl.buildCommanService(KnowledgeStoreServiceImpl.java:86)
... 28 more
Caused by: java.lang.RuntimeException: Unable to load session snapshot
at
org.drools.persistence.SessionMarshallingHelper.loadSnapshot(SessionMarshallingHelper.java:96)
at
org.drools.persistence.SingleSessionCommandService.initKsession(SingleSessionCommandService.java:229)
at
org.drools.persistence.SingleSessionCommandService.<init>(SingleSessionCommandService.java:177)
... 33 more
Caused by: java.lang.NullPointerException
at
org.drools.common.ConcurrentNodeMemories.getNodeMemory(ConcurrentNodeMemories.java:65)
at
org.drools.common.AbstractWorkingMemory.getNodeMemory(AbstractWorkingMemory.java:1040)
at
org.drools.marshalling.impl.InputMarshaller.readSession(InputMarshaller.java:231)
at
org.drools.marshalling.impl.InputMarshaller.readSession(InputMarshaller.java:203)
at
org.drools.marshalling.impl.DefaultMarshaller.unmarshall(DefaultMarshaller.java:92)
at
org.drools.persistence.SessionMarshallingHelper.loadSnapshot(SessionMarshallingHelper.java:91)
... 35 more
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6:59 a.m.
New subject: [jBPM] - Re: How to persist a timer
winton xu [http://community.jboss.org/people/winton] created the discussion
"Re: How to persist a timer"
To view the discussion, visit: http://community.jboss.org/message/629202#629202
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I have the same issue. it seems that there are problem on loading
StatefulKnowledgeSession.
this exception happen frequently,not only persist a timer.
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3:13 p.m.
New subject: [jBPM] - Re: How to persist a timer
Stefan Krause [http://community.jboss.org/people/krausest] created the discussion
"Re: How to persist a timer"
To view the discussion, visit: http://community.jboss.org/message/629427#629427
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I just noticed that the problem persists (pun intended) when I remove the timer event from
the diagram. Even if the process has only two script services loadStatefulKnowledgeSession
fails with the exception above. Looking at the rare examples that I find I can't see
any significant differences. The problem occurs only when an instance was or is active,
otherwise restoring the knowlede session works (but is pointless of course).
Has anyone a clue how I can make it work?
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12:11 p.m.
New subject: [jBPM] - Re: How to persist a timer
Stefan Krause [http://community.jboss.org/people/krausest] created the discussion
"Re: How to persist a timer"
To view the discussion, visit: http://community.jboss.org/message/630111#630111
--------------------------------------------------------------
Thanks for your help so far! I found that the problem occurs when I recreate the
KnowledgeBase. If I keep the KnowledgeBase (e.g. in a member variable) I can recreate the
session with JPAKnowledgeService.loadStatefulKnowledgeSession and everything is fine.
Here's how I create the KnowledgeBase:
{code}
KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
kbuilder.add(ResourceFactory.newClassPathResource("TimerPersistence.bpmn2"),
ResourceType.BPMN2);
KnowledgeBase knowledgeBase = kbuilder.newKnowledgeBase();
{code}
How can I handle recreation of the KnowledgeBase e.g. in a web app when I run in a new
java process?
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10:47 a.m.
New subject: [jBPM] - Re: How to persist a timer
Miljenko Norsic [http://community.jboss.org/people/mnorsic] created the discussion
"Re: How to persist a timer"
To view the discussion, visit: http://community.jboss.org/message/630262#630262
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Hi Stefan,
I had similar problems, and I resolved it by using the same Environment object. I see that
you create a new Environment every time when creating ProcessRunner, but essentially, you
are using the same knowledge session in a same thread.
Try to create Environment once, and pass it to ProcessRunner, and see if it works for
you.
Miljenko
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12:38 p.m.
New subject: [jBPM] - Re: How to persist a timer
Stefan Krause [http://community.jboss.org/people/krausest] created the discussion
"Re: How to persist a timer"
To view the discussion, visit: http://community.jboss.org/message/630281#630281
--------------------------------------------------------------
Thanks for your reply. Keeping the Environment object didn't help. Anyway I want to
simulate an appserver restart, so I have to recreate those objects. I'll create a jira
issue.
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6:37 a.m.
New subject: [jBPM] - Re: How to persist a timer
Mare Geldenhuys [http://community.jboss.org/people/mgeldenhuys] created the discussion
"Re: How to persist a timer"
To view the discussion, visit: http://community.jboss.org/message/630353#630353
--------------------------------------------------------------
Hi Stefan,
I was quite interested in your question, because we have to have long running processes as
well. So I spent some time to try and see how this can be solved. I used your test case
you uploaded to the JIRA to test and this is what I did:
When loading the KnowledgeSession you can pass in a reference to a KnowledgeBase.
StatefulKnowledgeSession ksession =
JPAKnowledgeService.loadStatefulKnowledgeSession(sessionId, knowledgeBase, null, env);
That solves the problem of loading a knowledge session with an already loaded knowledge
base.
You can write a knowledge base itself to external storage, the KnowledgeBaseImpl class is
Externalizable, and then read it again from external storage to load up you session.
This obviously does not solve the problem where the knowledgebase needs to be rebuilt
because of changes to the process definitions, but at least you can load sessions now with
existing process definitions.
You can also look at using a knowledge agent to load knowledge bases from Guvnor which
should manage changes to process definitions.
Mare
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9 a.m.
New subject: [jBPM] - Re: How to persist a timer
Marco Rietveld [http://community.jboss.org/people/marco.rietveld] created the discussion
"Re: How to persist a timer"
To view the discussion, visit: http://community.jboss.org/message/630381#630381
--------------------------------------------------------------
Mare,
Thanks -- that's a good tip.
Stefan,
Thanks for submitting the Jira (and the test case) -- I've been looking at the problem
this week and trying to find a solution for it. I've put most of the info on Jira.
Marco
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12:49 p.m.
New subject: [jBPM] - Re: How to persist a timer
Stefan Krause [http://community.jboss.org/people/krausest] created the discussion
"Re: How to persist a timer"
To view the discussion, visit: http://community.jboss.org/message/630427#630427
--------------------------------------------------------------
Thanks Mare and Marco. Actually my code looked like that before, but when I tried this and
that as a workaround I finally left (to my shame) the code passing null for the
knowledgeBase.
Marco commented on https://issues.jboss.org/browse/JBPM-3383
https://issues.jboss.org/browse/JBPM-3383 and found the real problem I ran into
originally, which is also a NullPointerException but caused by
ConcurrentNodeMemories.getNodeMemory(NodeMemory) line: 65.
Thank you both and sorry for causing additional trouble ;)
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1:34 a.m.
New subject: [jBPM] - Re: How to persist a timer
Mare Geldenhuys [http://community.jboss.org/people/mgeldenhuys] created the discussion
"Re: How to persist a timer"
To view the discussion, visit: http://community.jboss.org/message/630495#630495
--------------------------------------------------------------
No worries Stefan,
You asked an important question and raised an issue that needs to be solved (albeit with
the common programmer mistake of passing a null, we all do that by the way). The solution
I supplied is merely a workaround and not the optimal solution anyway. Marco is busy with
that (the optimal solution, that is).
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5303
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9 comments
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participants (5)
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Marco Rietveld -
Mare Geldenhuys
-
Miljenko Norsic
-
Stefan Krause
-
winton xu