I get the following error when I try to run a commit on a change to an entry in my database that I had previously created in another transaction.

org.hibernate.HibernateException: Error while indexing in Hibernate Search (before transaction completion)
at org.hibernate.search.backend.impl.EventSourceTransactionContext$DelegateToSynchronizationOnBeforeTx.doBeforeTransactionCompletion(EventSourceTransactionContext.java:175)
at org.hibernate.engine.ActionQueue$BeforeTransactionCompletionProcessQueue.beforeTransactionCompletion(ActionQueue.java:543)
at org.hibernate.engine.ActionQueue.beforeTransactionCompletion(ActionQueue.java:216)
at org.hibernate.impl.SessionImpl.beforeTransactionCompletion(SessionImpl.java:571)
at org.hibernate.jdbc.JDBCContext.beforeTransactionCompletion(JDBCContext.java:250)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:138)
at my.code tx.commit();

Caused by: java.util.ConcurrentModificationException
at java.util.HashMap$HashIterator.nextEntry(HashMap.java:793)
at java.util.HashMap$ValueIterator.next(HashMap.java:822)
at org.hibernate.search.engine.WorkPlan.processContainedInAndPrepareExecution(WorkPlan.java:119)
at org.hibernate.search.backend.WorkQueue.prepareWorkPlan(WorkQueue.java:133)
at org.hibernate.search.backend.impl.BatchedQueueingProcessor.prepareWorks(BatchedQueueingProcessor.java:124)
at org.hibernate.search.backend.impl.PostTransactionWorkQueueSynchronization.beforeCompletion(PostTransactionWorkQueueSynchronization.java:89)
at org.hibernate.search.backend.impl.EventSourceTransactionContext$DelegateToSynchronizationOnBeforeTx.doBeforeTransactionCompletion(EventSourceTransactionContext.java:172)
... 7 more
|#]

I have spent a couple of days trying to track this down, but no luck.

I should also mention that I am using the c3p0 connection pool. If anyone has any ideas, please let me know.

Hello,
thanks for reporting this, my fault!
Just on time to save the release.

http://opensource.atlassian.com/projects/hibernate/browse/HSEARCH-647

Hi,
I think the fix is pretty trivial and would like to merge it soon, but I'm having a hard time thinking about a unit test able to reproduce the bug. Could you please share a minimal unit test able to reproduce the error?
This is quite urgent to make sure it's fixed in the 3.3 release, thanks.

What I did was to create a new object and save it to the session and commit that transaction. Soon after, I started another transaction, changed a property of the object, and committed the transaction. The error then came on that second commit.

This didn't happen every time. It seems to be some complicated race condition. I never got this error with CR1 or earlier versions of HS.

Hopefully this is enough information for you. I am not at work right now, so this is the best I can do. I am in Japan, so it is already time to go to bed. I will be at work in about 10 hours, though...

Hi Makoto,
I would need to know how the object you saved was mapped, if you could provide a simplified version of your model (like just two entities with minimal set of properties).
I don't think it's a race condition, the name of the exception was badly chosen, but there should be a combination of model & data able to trigger it consistently.
Anyway, I think I've fixed it, please try the release we'll publish tomorrow; still I'd appreciate making a unit test so that we can be safe to regressions on this.

I downloaded the latest snapshot of 3.3 from 12/14 and I have not experienced this error with this version.

I will see about making a test case.

Thank you that would be great.
There are examples of very simple testcases in the sourcecode, example: https://github.com/Sanne/hibernate-search/blob/master/hibernate-search/src/test/java/org/hibernate/search/test/embedded/nested/containedIn/NestedContainedInTest.java. Hope it helps.

I will try to get to this next week.

The end of the year is a busy time!