org.hibernate.exception.LockAcquisitionException without any explicit lock

[avihai marchiano]

Hey,

using in Jboss, hibernate,spring,ms-sql.
I run multi threaded.

in some cases i get - org.hibernate.exception.LockAcquisitionException.

I dont have any explicit lock either by using in "select for update" or hibernate locking ...
But still when hibernate try to flush (and execute update bedore flush) it throw the exception based on deadlock in detected in the DB.

Caused by: org.hibernate.exception.LockAcquisitionException: Could not execute JDBC batch update
	at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:82)
	at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
	at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:253)
	at org.hibernate.jdbc.AbstractBatcher.prepareStatement(AbstractBatcher.java:92)
	at org.hibernate.jdbc.AbstractBatcher.prepareStatement(AbstractBatcher.java:87)
	at org.hibernate.jdbc.AbstractBatcher.prepareBatchStatement(AbstractBatcher.java:222)
	at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2354)
	at org.hibernate.persister.entity.AbstractEntityPersister.updateOrInsert(AbstractEntityPersister.java:2307)
	at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2607)
	at org.hibernate.action.EntityUpdateAction.execute(EntityUpdateAction.java:92)
	at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:250)
....
Caused by: java.sql.BatchUpdateException: com.microsoft.sqlserver.jdbc.SQLServerException: Transaction (Process ID 74) was deadlocked on lock resources with another process and has been chosen as the deadlock victim. Rerun the transaction.
	at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.executeBatch(Unknown Source)

Again - there is no lock in my code?
so - why hibetrnate or the DB lock? (as far as i know the default for hibernate is optimisitc lock).

Some googeling give "strang advices" like read all the data in the beging for ms-sql server ...

https://coderanch.com/t/415119/Object-Relational-Mapping/java/Deadlock-problems-with-Hibernate-Spring
...