StatelessSession does not flush when using jdbc batch_size > 1

Description

I'm using a StetelessSession to insert millions of rows : it works great and without using much memory. But I've just seen that with a jdbc batch size of 50 for example (<property name="hibernate.jdbc.batch_size" value="0"/> in my persistence.xml) the last round of inserts aren't flushed to the database. For example, with 70 insert, only the first 50 are sent to the database.

I've searched a lot about this issues and on this thread (https://forum.hibernate.org/viewtopic.php?f=1&t=987882&start=0), the only solution found is to set the batch_size to 1, which is really a shame.
I've tried to flush the session, close the jdbc connection, etc etc ... no luck.

I'd be fine with a way to set the batch_size to 1 only for this method, pro grammatically, but I've not found any way to do that.

If you don't pay attention, it's a easy way to lose data.

Subtasks

100% Done


Type	Key	Summary	Priority	Story Points	Assignee	Status
	HHH-5935	stateless session does not commit in batches by default, it commits one by one	Major		Unassigned

Activity

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Christian Beikov March 2, 2023 at 11:28 PM

Please create a new issue and attach a reproducer for this if that is still a problem in Hibernate 6

Felix König February 28, 2023 at 1:16 PM

Or, as a generic workaround snippet:

Session session = entityManager.unwrap(Session.class);
session.doWork(connection -> {
    try (StatelessSession statelessSession = session.getSessionFactory().openStatelessSession(connection)) {
        // do stuff with stateless session
        // workaround for https://hibernate.atlassian.net/browse/HHH-4042
        ((SharedSessionContractImplementor) statelessSession).getJdbcCoordinator().executeBatch();
    }
});

Felix König February 28, 2023 at 1:10 PM

This is still a problem and source of potential data loss in hibernate 6.1.7. For my case, which is Spring Boot, I’ve implemented this workaround:

@Service
public class StatelessSessionRunner {
  private final Session session;
  
  public StatelessSessionRunner(Session session) {
    this.session = session;
  }

  public <T> T runWithStatelessSession(Function<StatelessSession, T> func) {
    return session.doReturningWork(connection -> {
      try (StatelessSession statelessSession = session.getSessionFactory().openStatelessSession(connection)) {
        var result = func.apply(statelessSession);
        // workaround for https://hibernate.atlassian.net/browse/HHH-4042
        ((SharedSessionContractImplementor) statelessSession).getJdbcCoordinator().executeBatch();
        return result;
      }
    });
  }
}

Which allows you to perform some operations using a stateless session within a larger transaction.

Tobias Kremer June 27, 2013 at 9:02 AM

The workaround @sandermak posted does not work with Hibernate 4.2.2.

I found an new one:

final StatelessSession statelessSession = sessionFactory.openStatelessSession(connection);

/*
 * DO SOMETHING
 */

 ((TransactionContext) statelessSession).managedFlush(); //HACK to flush the session
 statelessSession.close();

I still do not understand why StatelessSession does not offer a method to flush the session.

Steve Ebersole March 21, 2011 at 7:08 PM

Bulk closing stale resolved issues

Rejected

Details

Assignee

Unassigned

Reporter

Gael Beaudoin

Components

hibernate-core

Affects versions

3.3.1

Priority

Major

Created July 17, 2009 at 2:23 AM

Updated March 2, 2023 at 11:28 PM

Resolved January 6, 2010 at 6:26 PM

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