Grails 2.0.1 Hibernation exception in foreign working branch

I have a Grails 2.0.1 application and I am creating worker threads. My worker threads use GORM to read / write domain objects from MySql. Given that the code that accesses the DB is not inside the HTTP request, I create a Hibernate session to persist () like this:

MyClass.withTransaction { status ->
    myClass.save()
}

      

        
        
        
      

    

I am doing this to solve the "No Sleeping Session Related to Thread" issue.

This worked great on Grails 1.3.7. I am currently trying to upgrade to Grails 2.0.1 and I see an exception that I do not understand.

The following stack trace shows the exception.

Although I recognize the exception and usually resolve it using the "withTransaction" technique shown above, what is confusing me is that this is happening in a worker thread that I have not created .

Exception in thread "pool-12-thread-2" org.hibernate.HibernateException: No Hibernate Session bound to thread, and configuration does not allow creation of non-transactional one here
at org.springframework.orm.hibernate3.SpringSessionContext.currentSession(SpringSessionContext.java:63)
at org.hibernate.impl.SessionFactoryImpl.getCurrentSession(SessionFactoryImpl.java:687)
at org.codehaus.groovy.grails.orm.hibernate.SessionFactoryProxy.getCurrentSession(SessionFactoryProxy.java:145)
at org.codehaus.groovy.grails.orm.hibernate.validation.HibernateDomainClassValidator.validate(HibernateDomainClassValidator.java:51)
at org.codehaus.groovy.grails.validation.GrailsDomainClassValidator.validate(GrailsDomainClassValidator.java:121)
at org.codehaus.groovy.grails.orm.hibernate.metaclass.ValidatePersistentMethod.doInvokeInternal(ValidatePersistentMethod.java:119)
at org.codehaus.groovy.grails.orm.hibernate.metaclass.AbstractDynamicPersistentMethod.invoke(AbstractDynamicPersistentMethod.java:63)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.springsource.loaded.ri.ReflectiveInterceptor.jlrMethodInvoke(ReflectiveInterceptor.java:1231)
at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite$PojoCachedMethodSite.invoke(PojoMetaMethodSite.java:189)
at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite.call(PojoMetaMethodSite.java:53)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:42)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:108)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:124)
at org.codehaus.groovy.grails.orm.hibernate.HibernateGormValidationApi.validate(HibernateGormEnhancer.groovy:702)
at com......MyClass.validate(MyClass.groovy)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.springsource.loaded.ri.ReflectiveInterceptor.jlrMethodInvoke(ReflectiveInterceptor.java:1231)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
at org.codehaus.groovy.grails.orm.hibernate.support.ClosureEventListener$7.call(ClosureEventListener.java:282)
at org.codehaus.groovy.grails.orm.hibernate.support.ClosureEventListener$7.call(ClosureEventListener.java:267)
at org.codehaus.groovy.grails.orm.hibernate.support.ClosureEventListener.doWithManualSession(ClosureEventListener.java:302)
at org.codehaus.groovy.grails.orm.hibernate.support.ClosureEventListener.onPreUpdate(ClosureEventListener.java:267)
at org.codehaus.groovy.grails.orm.hibernate.EventTriggeringInterceptor.onPreUpdate(EventTriggeringInterceptor.java:164)
at org.codehaus.groovy.grails.orm.hibernate.EventTriggeringInterceptor.onPersistenceEvent(EventTriggeringInterceptor.java:89)
at org.grails.datastore.mapping.engine.event.AbstractPersistenceEventListener.onApplicationEvent(AbstractPersistenceEventListener.java:46)
at org.springframework.context.event.SimpleApplicationEventMulticaster$1.run(SimpleApplicationEventMulticaster.java:92)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:680)

      

        
        
        
      

    

I hope someone can enlighten me regarding:

• where does this worker thread pool come from?
• why does the preUpdate event do (when I believe that the save in my thread has already successfully confirmed and saved
• Can I somehow tweak my application so that these worker worker threads aren't there.
• If # 3 cannot be disabled, how can I make the equivalent of "withTransaction" in the workflow code that I do not "own"