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Date: Wed, 2 Mar 2011 11:11:52 -0600
Message-ID: <AANLkTi=hm_b-SzPkQ0pXACJf9NjuEMQ6KkiN_d9xtF4c@mail.gmail.com>
Subject: Re: Optimistic lock problem
From: Rick Curtis <curtisr7@gmail.com>
To: users@openjpa.apache.org
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Kawanaka -

I'm going to start with my typical first question.... How are you enhancing
your Entities? Can you post the contents of your persistence.xml file?

Thanks,
Rick

On Wed, Mar 2, 2011 at 10:31 AM, KAWANAKA Shinya <mayahjp+ml@mayah.jp>wrote:

> Hi list,
>
> I encountered the weird situation that an optimistic lock violation
> happened. I would like you to judge this is my fault or a bug.
>
> First I created an entity listed on here (https://gist.github.com/851075).
> Then I wrote several tests that used the entity. In the following test, an
> optimistic lock violation happened.
>
> === CODE STARTS HERE ===
>        EntityManager em = emf.createEntityManager();
>        {
>            em.getTransaction().begin();
>            for (int i = 0; i < 10; ++i) {
>                Questionnaire q = new Questionnaire("id" + i, "eventId",
> "question", i, "answerText");
>                em.persist(q);
>            }
>            // em.flush(); // (1)
>            em.getTransaction().commit();
>        }
>
>        {
>            em.getTransaction().begin();
>            // em.flush(); // (3)
>            Query q = em.createQuery("DELETE FROM Questionnaires t");
>            q.executeUpdate();
>            em.getTransaction().commit(); // (2)
>        }
>
>        em.close();
> === CODE END HERE ===
>
> In (2) the exception happened. The stack trace is attached at the last.
> When I changed the field type of 'questionNo' to Integer (int -> Integer),
> the violation did not happen.
>
> Some one advised me to use flush() at (1), but it did not help.
>
> When I added (3) and traced the function, I found that
> ImplHelper.getUpdateField(sm) in AbstractUpdateManager#populateRowManager
> returned a dirty flag that said the 'questionNo' was dirty.
>
> === CODE HERE ===
>            } else if ((dirty = ImplHelper.getUpdateFields(sm)) != null) {
>                update(sm, dirty, (ClassMapping) sm.getMetaData(), rowMgr,
>                    store, customs, false);
> === END ===
>
> I only used a single thread, so I don't think the entities were changed in
> the other threads. (Remember that the field type of 'questionNo' was changed
> to Integer, the code worked.)
>
> Does anyone know why the violation happens?
>
> My environment is
>  Mac OS X Snow leopard, Sun Java 6, and OpenJPA-2.0.1.
>
>
>
> Exception in thread "main" <openjpa-2.0.1-r422266:989424 fatal store error>
> org.apache.openjpa.persistence.RollbackException: Optimistic locking errors
> were detected when flushing to the data store.  The following objects may
> have been concurrently modified in another transaction:
> [entity.Questionnaire-id3, entity.Questionnaire-id1,
> entity.Questionnaire-id5, entity.Questionnaire-id2,
> entity.Questionnaire-id6, entity.Questionnaire-id0,
> entity.Questionnaire-id8, entity.Questionnaire-id9,
> entity.Questionnaire-id4, entity.Questionnaire-id7]
>        at
> org.apache.openjpa.persistence.EntityManagerImpl.commit(EntityManagerImpl.java:584)
>        at client.Test.run(Test.java:44)
>        at client.Test.main(Test.java:17)
> Caused by: <openjpa-2.0.1-r422266:989424 nonfatal store error>
> org.apache.openjpa.persistence.OptimisticLockException: Optimistic locking
> errors were detected when flushing to the data store.  The following objects
> may have been concurrently modified in another transaction:
> [entity.Questionnaire-id3, entity.Questionnaire-id1,
> entity.Questionnaire-id5, entity.Questionnaire-id2,
> entity.Questionnaire-id6, entity.Questionnaire-id0,
> entity.Questionnaire-id8, entity.Questionnaire-id9,
> entity.Questionnaire-id4, entity.Questionnaire-id7]
>        at
> org.apache.openjpa.kernel.BrokerImpl.newFlushException(BrokerImpl.java:2291)
>        at org.apache.openjpa.kernel.BrokerImpl.flush(BrokerImpl.java:2139)
>        at
> org.apache.openjpa.kernel.BrokerImpl.flushSafe(BrokerImpl.java:2037)
>        at
> org.apache.openjpa.kernel.BrokerImpl.beforeCompletion(BrokerImpl.java:1955)
>        at
> org.apache.openjpa.kernel.LocalManagedRuntime.commit(LocalManagedRuntime.java:81)
>        at org.apache.openjpa.kernel.BrokerImpl.commit(BrokerImpl.java:1479)
>        at
> org.apache.openjpa.kernel.DelegatingBroker.commit(DelegatingBroker.java:925)
>        at
> org.apache.openjpa.persistence.EntityManagerImpl.commit(EntityManagerImpl.java:560)
>        ... 2 more
> Caused by: <openjpa-2.0.1-r422266:989424 nonfatal store error>
> org.apache.openjpa.persistence.OptimisticLockException: An optimistic lock
> violation was detected when flushing object instance
> "entity.Questionnaire-id3" to the data store.  This indicates that the
> object was concurrently modified in another transaction.
> FailedObject: entity.Questionnaire@72940b84
>        at
> org.apache.openjpa.jdbc.kernel.PreparedStatementManagerImpl.flushAndUpdate(PreparedStatementManagerImpl.java:123)
>        at
> org.apache.openjpa.jdbc.kernel.BatchingPreparedStatementManagerImpl.flushAndUpdate(BatchingPreparedStatementManagerImpl.java:81)
>        at
> org.apache.openjpa.jdbc.kernel.PreparedStatementManagerImpl.flushInternal(PreparedStatementManagerImpl.java:99)
>        at
> org.apache.openjpa.jdbc.kernel.PreparedStatementManagerImpl.flush(PreparedStatementManagerImpl.java:87)
>        at
> org.apache.openjpa.jdbc.kernel.ConstraintUpdateManager.flush(ConstraintUpdateManager.java:550)
>        at
> org.apache.openjpa.jdbc.kernel.ConstraintUpdateManager.flush(ConstraintUpdateManager.java:107)
>        at
> org.apache.openjpa.jdbc.kernel.BatchingConstraintUpdateManager.flush(BatchingConstraintUpdateManager.java:59)
>        at
> org.apache.openjpa.jdbc.kernel.AbstractUpdateManager.flush(AbstractUpdateManager.java:103)
>        at
> org.apache.openjpa.jdbc.kernel.AbstractUpdateManager.flush(AbstractUpdateManager.java:76)
>        at
> org.apache.openjpa.jdbc.kernel.JDBCStoreManager.flush(JDBCStoreManager.java:731)
>        at
> org.apache.openjpa.kernel.DelegatingStoreManager.flush(DelegatingStoreManager.java:131)
>        ... 9 more
>
>
> --
> Kawanaka Shinya <mayahjp+ml@mayah.jp>
> http://mayah.jp/
>
>
>
>
>
>
>

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