application freeze when trying to save an object

[hugo]

Hi,
I use hibernate and spring in an application. I migrate from an old application that was previously in pure jdbc connection.
All unit tests for my DAOs work but I have a problem in a real case that I can't reproduce in unit test (but I can reproduce every time in a real case).

I know that I freeze in a DAO when I try to do :

        getCurrentSession().saveOrUpdate(obj);

Just before that, I saw in debug mode :

2007.02.27 22:09:25,625 DEBUG Login Client /127.0.0.1 org.hibernate.impl.SessionImpl opened session at timestamp: 4803012876800000
2007.02.27 22:09:25,703 DEBUG Login Client /127.0.0.1 org.hibernate.jdbc.JDBCContext opening user JDBC connection, application must close it

Note that this is only in a second passage, the first one works.

I have the feelings that I have a problem with session but I'm not sure...

I use hibernate 3 and spring 2. Transaction are managed by interceptor in spring.xml. There is no open or close session in my code, I let Spring do all this work.

Any clue ?

[karldmoore]

Is it possible to see your applicationContext.xml and also explain which beans are getting called? It would also be useful to see more of the log.

[hugo]

The application context is attached to the post.

To explain a little :
- a user connect to the server, I use the dao to check is user is present in database, I check password. If connection succeed, I use DAO to update last connexion time.
And now, after the migration with hibernate/spring, the first connexion works, but if I retry, it freeze when I use the DAO to update last connexion time.
=> it always freeze in AccountsDAO

The code is quite basic :

    /**
     * Either save() or update() the given instance, depending upon the value of its
     * identifier property.
     */
    public void saveOrUpdate(Object obj) {
        getSessionFactory().getCurrentSession().saveOrUpdate(obj);
    }

Here is the log of hibernate and spring in debug mode the first time I login : logFirstTry.txt


And the second time : logSecondTry.txt

nothing more after this.

I think I could try to see with mysqladministrator how many connexion are open but I don't know if would be helpfull.

[karldmoore]

Are you using HibernateDaoSupport with Hibernate? If so you can just call getHibernateTemplate.saveOrUpdate(..) instead. It would be useful to suspend the threads in Eclipse and see where the code is getting stuck. Turning on SQL logging in Hibernate might also give some hints.

[hugo]

I extend my DAO from hibernateDAOSupport but I don't use HibernateTemplate as it is recommended by the spring documentation for hibernate3 :

http://www.springframework.org/docs/...aoSupport.html

NOTE: As of Hibernate 3.0.1, transactional Hibernate access code can also be coded in plain Hibernate style. Hence, for newly started projects, consider adopting the standard Hibernate3 style of coding data access objects instead, based on SessionFactory.getCurrentSession().

The log I attached is already in show_sql=true
Wee see that the second update is not made.

I have to try to debug in eclipse. It's just hard for the moment to have the application and eclipse on the same machine ^^

[Injecteer]

couple of ideas:

1. see Hibernate is leaking JDBC connections!

2. if you have a declarative TX management, and the method where you call saveOrUpdate() is declared as transactional, then you don't realy need to call it, as the hibernate checks for the dirty objects during flushing just before the end of transaction and session. Of course, if the object is not persistant, you'll have to call save( obj ).

[hugo]

In point 1. it is a point about session management. But I delegate this problematic to Spring, I don't open or close a session.
In point 2., I understand the point, but do you think that saveOrUpdate could leak a session if I call it instead of save ? I'm not sure.
I really have to find a way to debug under eclipse without crashing my machine ^^

[karldmoore]

Looking at the logs, Injecteer's suggestions do seem very possible. It's trying to get a connection but can't and it's therefore hung. I do appreciate what you are saying however and wonder how it can actually get into this position. Debugging it will obviously point to the problem, if eclipse will actually let you do it!

[Injecteer]

No, point 1 has nothing to do with the session management (at least directly) .
I mean, in your context.xml you let hibernate's SF manage the pooling:

	<bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
		<property name="hibernateProperties">
			<props>
			   <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
			   <prop key="hibernate.show_sql">false</prop>
			   <prop key="hibernate.c3p0.min_size">1</prop>
			   <prop key="hibernate.c3p0.max_size">20</prop>
			   <prop key="hibernate.c3p0.timeout">0</prop>
			   <prop key="hibernate.c3p0.max_statement">100</prop>
			   <prop key="hibernate.c3p0.idle_test_period">60</prop>

instead, I would put it into the dataSource's definition. There's a plenty of setters for that.
In my projects in "hibernateProperties" I define only hibernate-specific entries, like dialect, caching etc.

Also, I'd disable the pooling at all just to see if there are any differences.

[karldmoore]

That seems like a good idea! If you want to try without connection pooling then go for DriverManagerDataSource. Otherwise the attached link has an example of setting up c3p0 as a dataSource.
http://www.springframework.org/docs/...ataSource.html
http://forum.springframework.org/showthread.php?t=33166