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
> >>
> >>
> >
>
