Hi Romain.

I don't really understand your solution. Can you please provide me with
simple exmaple.... So I'll understand.

BR

MAtej

2015-03-09 22:59 GMT+01:00 Romain Manni-Bucau <[email protected]>:

> Why not using a dependson singleton as delegate in your mdb as mentionned?
> Fast and reliable  as fix imo
> Le 9 mars 2015 22:13, "Matej" <[email protected]> a écrit :
>
> > Would something like that help. That's probably something what David
> meant.
> >
> > @Singleton
> > @Startup
> > @Lock(LockType.READ)
> > @ConcurrencyManagement(ConcurrencyManagementType.CONTAINER)
> > public class UniversalConfigurationService {
> >
> >     @Inject
> >     UniversalConfigurationDao configDao;
> >
> >     private ConcurrentHashMap<Integer, ConcurrentHashMap<Integer,
> > ConfigValue>> configCache = new ConcurrentHashMap<>();
> >
> >     @PostConstruct
> > @Lock(LockType.WRITE) //probably not nedded right?
> >     public void init() {
> >         this.configCache = configDao.getAllConfigurations();
> >     }
> > }
> >
> > 2015-03-09 19:10 GMT+01:00 Matej <[email protected]>:
> >
> > > I added a short stacktrace. Will try to provide better one. Somehow is
> > > seems, like the system is not fully initialized, like some injection
> > > missing.. Without the (configurationService.getBoolean, everything
> loads
> > > normally. Is the MDB system initialized before EJBs?
> > >
> > >
> > > Here is the Singleton snippet:
> > > @Singleton
> > > @Startup
> > > @ConcurrencyManagement(ConcurrencyManagementType.BEAN)
> > > public class UniversalConfigurationService {
> > >
> > >     @Inject
> > >     UniversalConfigurationDao configDao;
> > >
> > >     private ConcurrentHashMap<Integer, ConcurrentHashMap<Integer,
> > > ConfigValue>> configCache = new ConcurrentHashMap<>();
> > >
> > >     @PostConstruct
> > >     public void init() {
> > >         this.configCache = configDao.getAllConfigurations();
> > >     }
> > > }
> > >
> > > and here te MDB
> > >
> > > MessageDriven(activationConfig = {
> > >     @ActivationConfigProperty(propertyName = "destinationType",
> > > propertyValue = "javax.jms.Queue"),
> > >     @ActivationConfigProperty(propertyName = "destination",
> propertyValue
> > > = "EtaStatisticalRes")})
> > > @DependsOn("UniversalConfigurationService")
> > > public class EtaStatisticalResHandler implements MessageListener {
> > >
> > >     @Inject
> > >     public Logger logger;
> > >
> > >     @Inject
> > >     UniversalConfigurationService configurationService;
> > >
> > >     @Override
> > >     public void onMessage(Message message) {
> > >
> > >         if (configurationService.getBoolean(ETA.getCode(),
> > > EMBEDDED_ETA_REPORTING.getCode())) {
> > >             return;
> > >         }
> > > }
> > >
> > >
> > >
> > >
> > >
> > > 2015-03-08 5:31 GMT+01:00 David Blevins <[email protected]>:
> > >
> > >> The @DependsOn annotation only works for other @Singleton beans.
> > >>
> > >> Definitely use CONTAINER concurrency.  Understand that this code is
> just
> > >> a plain jvm ReentrantReadWriteLock under the covers.  It would be hard
> > to
> > >> do much better.
> > >>
> > >>  -
> > >>
> >
> http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/locks/ReentrantReadWriteLock.html
> > >>
> > >> All methods annotated with an @Lock(READ) acquire a read lock.  All
> > >> methods annotated with @Lock(WRITE) acquire a write lock.
> > >>
> > >> That said, if you're already doing the configuration initialization in
> > >> the @PostConstruct of the @Singleton, this issue shouldn't exist.
> > >>
> > >> Can you paste the stacktrace of your NPE?
> > >>
> > >>
> > >> --
> > >> David Blevins
> > >> http://twitter.com/dblevins
> > >> http://www.tomitribe.com
> > >>
> > >> On Mar 7, 2015, at 3:51 AM, Matej <[email protected]> wrote:
> > >>
> > >> > Hi everybody.
> > >> >
> > >> > We have an annoying problem on our production system. We have an
> > >> > Configuration Singleton which reads config things from DB. Then in
> one
> > >> MDB
> > >> > we inject this Singleton to control operation based on configs. Our
> > >> problem
> > >> > is that the system is quite heavely loadded and while the system
> > >> startups
> > >> > already MDB recievs onMessage events while the Singleton still
> > >> initliazes.
> > >> > Which produces some NPEs and system doesn't boot.
> > >> >
> > >> > The depneds on annotation seems not to help. We are doing BEAN
> > >> conncurency
> > >> > management could this be the issue? And the Singleton has an
> > >> Postconstruct
> > >> > annotation.
> > >> >
> > >> > Anyone has any pattern or tips how to handle this type of scenario.
> > >> >
> > >> > BR
> > >> >
> > >> > Matej
> > >>
> > >>
> > >
> >
>

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