Description Michael OBrien 2010-09-10 10:35:49 EDT

>This enhancement is requested by PM
>Problem: Users may want to do an early session.login() to the DB on EntityManagerFactory predeploy instead of waiting for the first EntityManager deploy
This functionality when enabled via a "new" persistence.xml property would extend the existing "validation-only" flag to also do a login in addition to presently initializing descriptors.
History: The fix for bug # 322585, bug # 303063 and bug # 297928 introduced an early login only for the emf.getMetamodel() or emf.getCriteriaBuilder() case via an emf.getServerSession() call.
This enhancement would extend this early login by adding a getServerSession() call into the emf.predeploy() directly if this flag was set.

>Forensics and Volumetrics

======Performance Results 106-3======
  The following show that that the time taken to update the session, do DDL generation and intialize the metamodel and canonical metamodel has shifted to the EMF creation from the EM creation.  In essence an '''emf.createEntityManager()''' now takes just a couple microseconds instead of seconds.
  Doing all the following in the predeploy
    updateServerSession
    session.login
    generateDDL
    metamodel initalization
    canonical metamodel initialization
  takes in '''SE'''
    '''with change'''
      predeploy() = 2.6 sec
        [EL Finest]: 2010-08-17 18:01:12.002--ServerSession(27196165)--Thread(Thread[main,5,main])--Begin predeploying Persistence Unit dao.create.tables.derby; session default-session; state Initial; factoryCount 0
        [EL Finest]: 2010-08-17 18:01:14.67--ServerSession(27196165)--Thread(Thread[main,5,main])--End deploying Persistence Unit dao.create.tables.derby; session default-session; state Deployed; factoryCount 1
      deploy() = 0.09 sec 
        [EL Finest]: 2010-08-17 18:01:14.67--ServerSession(27196165)--Thread(Thread[main,5,main])--End deploying Persistence Unit dao.create.tables.derby; session default-session; state Deployed; factoryCount 1
        [EL Finer]:  2010-08-17 18:01:14.763--ServerSession(27196165)--Thread(Thread[main,5,main])--client acquired
    '''without change'''
      predeploy() = 0.75 sec
        [EL Finest]: 2010-08-17 17:58:29.169--ServerSession(2279771)--Thread(Thread[main,5,main])--Begin predeploying Persistence Unit dao.create.tables.derby; session default-session; state Initial; factoryCount 0
        [EL Finest]: 2010-08-17 17:58:29.934--ServerSession(2279771)--Thread(Thread[main,5,main])--End predeploying Persistence Unit dao.create.tables.derby; session default-session; state Predeployed; factoryCount 1
      deploy() = 1.87 sec
        [EL Finest]: 2010-08-17 17:58:29.934--ServerSession(2279771)--Thread(Thread[main,5,main])--Begin deploying Persistence Unit dao.create.tables.derby; session default-session; state Predeployed; factoryCount 1
        [EL Finer]:  2010-08-17 17:58:31.806--ServerSession(2279771)--Thread(Thread[main,5,main])--client acquired

  On emf.createEntityManager() we just skip deploy/login in getServerSession(), login in createEntityManagerImpl as well as deploy/login in getServerSession() in the EntityManagerImpl constructor
  because the emf.createEntityManager() does virtually nothing after this change
    EE Server testing on WebLogic 10.3.3.0 via standard @PersitenceContext injection on a SSB @EJB injected on a servlet client is OK
    Notice that a predeploy also does a deploy now - previously the deploy was only done when the client persisted or read from the persistence unit (via injection)
>stacktrace of change
    Daemon Thread [[ACTIVE] ExecuteThread: '0' for queue: 'weblogic.kernel.Default (self-tuning)'] (Suspended (breakpoint at line 314 in EntityManagerSetupImpl))	
	EntityManagerSetupImpl.deploy(ClassLoader, Map) line: 314	
	EntityManagerFactoryImpl.getServerSession() line: 157	
	PersistenceProvider.createContainerEntityManagerFactory(PersistenceUnitInfo, Map) line: 243	
	PersistenceUnitInfoImpl.createEntityManagerFactory(boolean) line: 352	
	PersistenceUnitInfoImpl.createEntityManagerFactory() line: 332	
	PersistenceUnitInfoImpl.<init>(PersistenceUnitBean, PersistenceUnitConfigurationBean, GenericClassLoader, String, URL, URL) line: 134	
	ModulePersistenceUnitRegistry(AbstractPersistenceUnitRegistry).storeDescriptors(Map, Map) line: 336	
	ModulePersistenceUnitRegistry(AbstractPersistenceUnitRegistry).loadPersistenceDescriptor(VirtualJarFile, boolean, File) line: 250	
	ModulePersistenceUnitRegistry.<init>(GenericClassLoader, ApplicationContextInternal, Module, boolean) line: 69	
	EJBModule.setupPersistenceUnitRegistry() line: 221