> I'm having a strange memory problem when committing transactions with BLOBs in many threads, using Hibernate and Jaybird on Java with Firebird. Here's my setup:
>
> - Firebird 2.5
> - JDK 1.6.0
> - Jaybird 2.1.6
> - Hibernate 3.5.6
>
> I have a daemon task which at certain times spawns many tasks that load a BLOB, does calculations on it, and stores the result either in a new row in another table, or it saves back a changed version of the original BLOB. The tasks correctly commit the transactions and close the hibernate session.
>
> After some time of correctly committing the transactions, the tasks start to give the following exception:
>
> org.hibernate.exception.GenericJDBCException: could not insert: [ch.gutermann.zonescan.model.SummedMeasurement]
> at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:140)
> at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:128)
> at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
> at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2438)
> at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2858)
> at org.hibernate.action.EntityInsertAction.execute(EntityInsertAction.java:79)
> at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:267)
> at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:259)
> at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:178)
> at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
> at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51)
> at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1206)
> at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:375)
> at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137)
> at ch.gutermann.zonescan.server.correlation.MeasAveragingTask.run(MeasAveragingTask.java:155)
> at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
> at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
> at java.lang.Thread.run(Unknown Source)
> Caused by: org.firebirdsql.jdbc.FBSQLException: I/O Exception. could not close blob: org.firebirdsql.gds.GDSException: unable to allocate memory from operating system
> at org.firebirdsql.jdbc.FBBlob.copyBytes(FBBlob.java:516)
> at org.firebirdsql.jdbc.field.FBBlobField.copyBytes(FBBlobField.java:265)
> at org.firebirdsql.jdbc.field.FBBlobField.flushCachedData(FBBlobField.java:239)
> at org.firebirdsql.jdbc.AbstractPreparedStatement.flushFields(AbstractPreparedStatement.java:749)
> at org.firebirdsql.jdbc.AbstractPreparedStatement.internalExecute(AbstractPreparedStatement.java:723)
> at org.firebirdsql.jdbc.AbstractPreparedStatement.executeUpdate(AbstractPreparedStatement.java:190)
> at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeUpdate(NewProxyPreparedStatement.java:105)
> at org.hibernate.jdbc.NonBatchingBatcher.addToBatch(NonBatchingBatcher.java:46)
> at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2418)
> ... 14 more
>
> When this happens, every subsequent task will give the same error, "unable to allocate memory from operating system". However, when I wait several minutes and then start the tasks again, the tasks will run correctly again for some time, potentially starting to give the error again later on.
>
> This sounds to me like some kind of buffer is being overflowed. But what kind of buffer is it, and how can I avoid this from happening?

Perhaps it is better to move this to the Firebird-java list?



--
With regards,

Thomas Steinmaurer
Upscene Productions
http://www.upscene.com
http://blog.upscene.com/thomas/

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