Hibernate version:3.2.5.ga

Hi,

If you want to manage transactions on multiple databases connections, can you do that with Hibernate?

For instance, I want to update data on both databases, but the first transaction on a DB has to be rollback after second transaction on the other DB fails. How can you handle this kind scenario?

Thanks in advance.

Brad

You need to set up distributed transaction in your data sources. That usually involves using the XA version of drivers. However, this will impact performance.



Farzad-

Hi Farzad

Thanks for your quick answer and valuable information. I tried to implement it, however I got a error message
“org.hibernate.TransactionException: could not register synchronization”.
Would you correct me what I am wrong from the following?

Thanks again,
Brad

===Oracle JDBC Driver (XA) on Websphere datasource===
oracle.jdbc.xa.client.OracleXADataSource

===hibernate configuration===
<hibernate-configuration>
<session-factory>
<property name="hibernate.dialect">org.hibernate.dialect.Oracle9iDialect</property>
<property name="hibernate.connection.datasource">jdbc/dsXA1</property>

<property name="hibernate.transaction.factory_class">
org.hibernate.transaction.CMTTransactionFactory
</property>
<property name="hibernate.transaction.manager_lookup_class">
org.hibernate.transaction.WebSphereExtendedJTATransactionLookup
</property>

<property name="show_sql">true</property>
<property name="current_session_context_class">thread</property>
<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
</session-factory>
</hibernate-configuration>

===Java dao code===
for (int idx=0; idx<InitSessionFactory.NUMBER_OF_INSTATNCE; idx++)
{
try
{
Session session = InitSessionFactory.getCurrentSession(idx);
session.saveOrUpdate(obj);
}
catch ( Exception e )
{
e.printStackTrace();
log.error(": Exception on <updateTestOR>: " + e.getMessage());
}
}

If I use “JTATransactionFactory” in hibernate configuration, this error message is shown.
“org.hibernate.TransactionException: could not register synchronization with JTA TransactionManager”

<property name="hibernate.transaction.factory_class">
org.hibernate.transaction.JTATransactionFactory
</property>
<property name="hibernate.transaction.manager_lookup_class">
org.hibernate.transaction.WebSphereExtendedJTATransactionLookup
</property>

Can you give me the whole stack trace? What if you don't specify the factory class and only transaction manager lookup class?

And just my curiosity, you have two session factories right?


Farzad-

And also, here is error stack when org.hibernate.transaction.CMTTransactionFactory is used.

0000002e SystemErr R org.hibernate.TransactionException: Could not register synchronization
at org.hibernate.transaction.CMTTransaction.registerSynchronization(CMTTransaction.java:159)
at org.hibernate.context.ThreadLocalSessionContext.currentSession(ThreadLocalSessionContext.java:78)
at org.hibernate.impl.SessionFactoryImpl.getCurrentSession(SessionFactoryImpl.java:544)
at com.ibm.msp.webtim.hibernate.InitSessionFactory.getCurrentSession(InitSessionFactory.java:87)
at com.ibm.msp.webtim.dao.TestORDao.updateTestOR(TestORDao.java:59)
at webtest.actions.FirstAction.execute(FirstAction.java:37)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:484)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:274)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1482)
at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:507)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:743)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1212)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:629)
at com.ibm.ws.webcontainer.webapp.WebApp.handleRequest(WebApp.java:2837)
at com.ibm.ws.webcontainer.webapp.WebGroup.handleRequest(WebGroup.java:220)
at com.ibm.ws.webcontainer.VirtualHost.handleRequest(VirtualHost.java:204)
at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:1681)
at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:77)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:421)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleNewInformation(HttpInboundLink.java:367)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.ready(HttpInboundLink.java:276)
at com.ibm.ws.tcp.channel.impl.NewConnectionInitialReadCallback.sendToDiscriminaters(NewConnectionInitialReadCallback.java:201)
at com.ibm.ws.tcp.channel.impl.NewConnectionInitialReadCallback.complete(NewConnectionInitialReadCallback.java:103)
at com.ibm.ws.tcp.channel.impl.WorkQueueManager.requestComplete(WorkQueueManager.java:548)
at com.ibm.ws.tcp.channel.impl.WorkQueueManager.attemptIO(WorkQueueManager.java:601)
at com.ibm.ws.tcp.channel.impl.WorkQueueManager.workerRun(WorkQueueManager.java:934)
at com.ibm.ws.tcp.channel.impl.WorkQueueManager$Worker.run(WorkQueueManager.java:1021)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java(Compiled Code))
Caused by: org.hibernate.HibernateException: java.lang.reflect.InvocationTargetException
at org.hibernate.transaction.WebSphereExtendedJTATransactionLookup$TransactionManagerAdapter$TransactionAdapter.registerSynchronization(WebSphereExtendedJTATransactionLookup.java:165)
at org.hibernate.transaction.CMTTransaction.registerSynchronization(CMTTransaction.java:156)
... 28 more
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java(Compiled Code))
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java(Compiled Code))
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java(Compiled Code))
at java.lang.reflect.Method.invoke(Method.java(Compiled Code))
at org.hibernate.transaction.WebSphereExtendedJTATransactionLookup$TransactionManagerAdapter$TransactionAdapter.registerSynchronization(WebSphereExtendedJTATransactionLookup.java:159)
... 29 more
Caused by: com.ibm.websphere.jtaextensions.NotSupportedException
at com.ibm.ws.jtaextensions.ExtendedJTATransactionImpl.registerSynchronizationCallbackForCurrentTran(ExtendedJTATransactionImpl.java:227)
... 35 more

Here is SessionFactory java code which creates multiple SessionFactory, same as the size of CONFIG_FILE_LOCATIONS[].

private static synchronized void initSessionFactory(int idx)
{
if (sessionFactory[idx] == null)
{
try
{
cfg[idx] = new Configuration();
cfg[idx].configure(new URL (CONFIG_FILE_LOCATIONS[idx]));//Hibernate configuration files

String sessionFactoryJndiName
= cfg[idx].getProperty(Environment.SESSION_FACTORY_NAME);
if (sessionFactoryJndiName != null) {
cfg[idx].buildSessionFactory();
log.debug("get a jndi session factory");
sessionFactory[idx] = (SessionFactory) (new InitialContext())
.lookup(sessionFactoryJndiName);
} else{
log.debug("classic factory");
sessionFactory[idx] = cfg[idx].buildSessionFactory();
}

sessionFactory[idx] = cfg[idx].buildSessionFactory();
}
catch (Exception e)
{
log.error("%%%% Error Creating HibernateSessionFactory %%%%");
e.printStackTrace();
throw new HibernateException(
"Could not initialize the Hibernate configuration");
}
}
}

What WAS version are you using?


Farzad-

WAS 6.1
Hibernate 3.2.5
Oracle 9i

According to WAS documents, the exception says:




This means your call is most likely not in an scope of a transaction at all, and as I can see from stack trace I don't see a point which implies creating a new transaction. It's a web call. You will need to demarcate this call in a transaction scope. You can either get a UserTransaction or get a framework like Spring to have it done for you.


Farzad-

Thanks Farzad

The issue has been solved with your idea.
UserTransaction is taken from Session bean (BMP) and it sets transaction scope in session bean method which calls Hibernate DAO class. The method of the DAO class updates data into multiple data source. It works fine (even I don’t do performance testing yet).

Here is hibernate configuration and EJB method for another people who try to find out a example code of distributed transaction management.

<hibernate-configuration>
<session-factory>
<property name="hibernate.dialect">org.hibernate.dialect.Oracle9iDialect</property>
<property name="hibernate.connection.datasource">jdbc/dsXA1</property>

<property name="hibernate.transaction.factory_class">
org.hibernate.transaction.CMTTransactionFactory
</property>
<property name="hibernate.transaction.manager_lookup_class">
org.hibernate.transaction.WebSphereExtendedJTATransactionLookup
</property>

<property name="show_sql">true</property>
<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>

<!-- Mapping files -->
<mapping resource="webtest.hbm.xml"/>

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


==EJB method (BMP)===
public void updateTestOR(TestOR obj) throws Exception
{
UserTransaction ut = getSessionContext().getUserTransaction();
try {
ut.begin();
TestORDao objDao = new TestORDao();
objDao.updateTestOR(obj);
ut.commit();
} catch (Exception e) {
ut.rollback();
}
}

I'm using Required level transactions and I get the same exception.
Since I'm using Container Managed Transactions and not not using bean managed transactions I can not do this:



So how do I solve this in my situation?

Shawn

Has HB been configured with a JTA transaction manager?


Farzad-

Yes

What if you change the CMTTransactionFactory to a JTATransactionFactory? I don't recall the difference from top of my head but JTA would be a better fit I guess.


Farzad-