Hi,
I use version 3.0.1 with HSQLDB and continuosly encounter when executing fast SQL statements. I broke it down to a very simple example, happens in different circumstances too, though:

"Could not execute JDBC batch update"

This code works fine with the sleep, but wihout the exception occurs:
for (int i = 0; i < 10; i++)
{
Human h = initRandomHuman();
manager.store(h);
humans.add(h);
Thread.sleep(1000);
}

where the manager executes:
public void store(Human human)
{
Transaction tx = session.beginTransaction();
session.save(human);
tx.commit();
}



This appears to be a timing problem. Seems, that Hibernate tries to optimize and executes all inserts in one "batch"? Any way I can disable this? Or, even better, make it work? The docu states that I should flush() and clear() the session, this did not help, though.
I have a low traffic application, the problems only occur while testing, not in production. Not yet, anyway.


Hibernate: insert into HUMANS (level, lastName, firstName, email, uid) values (?, ?, ?, ?, ?)
Hibernate: insert into HUMANS (level, lastName, firstName, email, uid) values (?, ?, ?, ?, ?)
WARN [main] (JDBCExceptionReporter.java:57) - SQL Error: 0, SQLState: null
ERROR [main] (JDBCExceptionReporter.java:58) - failed batch
ERROR [main] (AbstractFlushingEventListener.java:277) - Could not synchronize database state with session
org.hibernate.exception.GenericJDBCException: Could not execute JDBC batch update
at org.hibernate.exception.ErrorCodeConverter.handledNonSpecificException(ErrorCodeConverter.java:92)
at org.hibernate.exception.ErrorCodeConverter.convert(ErrorCodeConverter.java:80)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:179)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:226)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:136)
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:274)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:678)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:309)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:86)
at tecaf.basic.HumanManager.store(HumanManager.java:27)
at test.tecaf.basic.HumanManagerTest.testList(HumanManagerTest.java:79)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at junit.framework.TestCase.runTest(TestCase.java:154)
at junit.framework.TestCase.runBare(TestCase.java:127)
at junit.framework.TestResult$1.protect(TestResult.java:106)
at junit.framework.TestResult.runProtected(TestResult.java:124)
at junit.framework.TestResult.run(TestResult.java:109)
at junit.framework.TestCase.run(TestCase.java:118)
at junit.framework.TestSuite.runTest(TestSuite.java:208)
at junit.framework.TestSuite.run(TestSuite.java:203)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:474)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:342)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:194)
Caused by: java.sql.BatchUpdateException: failed batch
at org.hsqldb.jdbc.jdbcStatement.executeBatch(Unknown Source)
at org.hsqldb.jdbc.jdbcPreparedStatement.executeBatch(Unknown Source)
at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:57)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:172)
... 24 more

can you provide your mapping files ?

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
<session-factory>
<property name="hibernate.connection.driver_class">org.hsqldb.jdbcDriver</property>
<property name="hibernate.connection.url">jdbc:hsqldb:c:/x/data/test</property>
<property name="hibernate.connection.username">sa</property>
<property name="hibernate.connection.password"> </property>
<property name="dialect">org.hibernate.dialect.HSQLDialect</property>
<property name="show_sql">true</property>
<property name="transaction.factory_class">
org.hibernate.transaction.JDBCTransactionFactory
</property>
<property name="hibernate.cache.provider_class">
org.hibernate.cache.HashtableCacheProvider
</property>
<property name="hibernate.hbm2ddl.auto">update</property>

<property name="hibernate.connection.autocommit">false</property>

<mapping resource="resources/Human.hbm.xml"/>

</session-factory>
</hibernate-configuration>




<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>

<class name="tecaf.basic.Human" table="HUMANS" lazy="false">
<id name="id" column="uid" type="long">
<generator class="increment"/>
</id>
<property name="level" type="int" />
<property name="lastName" not-null="true"/>
<property name="firstName" not-null="true"/>
<property name="email" not-null="true" unique="true" />

</class>
</hibernate-mapping>

I've run a test using the information provided and I don't receive any exceptions. The only thing I wasn't able to duplicate is your initRandomHuman() method so is it possible that there is actually a data issue that's causing this exception ?

I was able to recreate your exception using

And the Thread.sleep(1000) fixed this because now obviously the getTime() would never be duplicated.

Using this problem did not exist.


Hope this helps.

Ouch, you are right. I actually use
human.setEmail("" + System.currentTimeMillis());
for the generation of my random data, but that is still too fast. Reducing the sleep to 10ms solves the problem.
Thanks a lot for the effort!

Stephan