Hello,
I have a problem, the code is like this...

method1(...)
{
//Create Session
...
iter1 = session.find(...).iterator();
while (iter1.hasNext())
{
obj = iter1.next();
...
method2(session, obj);
...
session.save(obj);
}

method2 (session, obj)
{
Query q = session.createQuery(...);
q.setParameter("xxx", obj.getXXX());
q.setParameter("yyy", obj.getYYY());
q.list() // HERE throws the exception
}


GRAVE: Could not synchronize database state with session
java.sql.SQLException: General error, message from server: "Deadlock found when trying to get lock; Try restarting transaction"
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:1628)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:886)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:945)
at com.mysql.jdbc.Connection.execSQL(Connection.java:1809)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1602)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1488)
at net.sf.hibernate.impl.NonBatchingBatcher.addToBatch(NonBatchingBatcher.java:22)
at net.sf.hibernate.persister.EntityPersister.insert(EntityPersister.java:478)
at net.sf.hibernate.persister.EntityPersister.insert(EntityPersister.java:454)
at net.sf.hibernate.impl.ScheduledInsertion.execute(ScheduledInsertion.java:20)
at net.sf.hibernate.impl.SessionImpl.executeAll(SessionImpl.java:2100)
at net.sf.hibernate.impl.SessionImpl.execute(SessionImpl.java:2061)
at net.sf.hibernate.impl.SessionImpl.autoFlushIfRequired(SessionImpl.java:1566)
at net.sf.hibernate.impl.SessionImpl.getQueries(SessionImpl.java:1372)
at net.sf.hibernate.impl.SessionImpl.find(SessionImpl.java:1332)
at net.sf.hibernate.impl.QueryImpl.list(QueryImpl.java:76)
at msyslog.acciones.LastMessageRepeatedAccion.run(LastMessageRepeatedAccion.java:38)
at msyslog.Main.runAcciones(Main.java:392)
at msyslog.Main.main(Main.java:222)

thanks,
C

Make sure to start your session's transaction, and to commit it after the save, as well as performing a flush() on the session after the save.

I see you're using a save() and not an update(), or saveOrUpdate().

After you've created obj from the iteration, do you make any changes to it before you get to the method2() call? Also, what is the query you perform in method2?

-G

Hello,
I have 2 bbdd:

Code in more detail:
main()
{
...
try{
...
// bbdd 1
sourceF = confSource.configure(confSourceFile).buildSessionFactory();
sessionSource = sessionsSource.openSession();
// bbdd2
destF = confDest.configure(confDestFile).buildSessionFactory();
sessionDest = sessionsDest.openSession();

// find in bbdd1
iter1 = sessionSource.find(...).iterator();
while (iter1.hasNext())
{
// Process obj to set attributes required in bbdd2
Syslog obj = (Syslog)iter1.next();
obj.setXXX(...);
...
method2(sessionDest, obj);
...
sessionDest.save(obj); // save in bbdd2
}
// Flush updates in bbdd1
sessionSource.flush();
sessionSource.connection().commit();
// Flush pending object inserts/updates in bbdd2
sessionDest.flush();
sessionDest.connection().commit();
...
}

method2 (sessionDest, obj)
{
...
Query q = session.createQuery(...);
q.setParameter("xxx", obj.getXXX());
q.setParameter("yyy", obj.getYYY());
q.list() // HERE throws the exception

iter1 = list.iterator();
while (iter1.hasNext())
{
// Process obj to set attributes required in bbdd2
Syslog obj = (Syslog)iter1.next();
obj.setXXX(...);
}
}

The exception always does not happen. the obj which I want to find and update in method2 can be of that I have processed (and saved in a previous iteration of main()) or that already was in bbdd2.

thanks,
C

* This is where the problem seems to happens. You change the data and I believe Hibernate puts a lock on that record.

* I assume that you start the transaction for each session before you being using them?

* Something that is bugging me, and hopefully one of the Hibernate team can answer this, is: when you create an object that is linked to a specific sessionFactory, can you simply save() that object in a completely different sessionFactory?

Would it not be better to have some class that takes that object as a parameter, and returns a "copy" of it. e.g.



I'm thinking it's the last thing - about the sessionFactory...

-G

Only it has failed once, but not identified the cause.
* I assume that you start the transaction for each session before you being using them?

Only use these 2 sessions, and only call sessionsFact.openSession() before find objects to process. start the transaction? it does not start hibernate?

and only flush and commit after processing (at end of main()).

The process:


the method2 findOtherObjectAndUpdateIt(sessionDest, obj) search another object in sessionDest (bbdd2):



the otherObject that i want to update can be of that I have processed in iter1 (a previous currentObj) or that already was in bbdd2 (not find in this iter1 bbdd1).

I don't know if the problem is transactions, or if the otherObject is one of previously process (found in bbdd1) and still has not been flush and commit or what?

Thanks again for all,
Cesar.

PD: You excuse my terrible english.