The point is that @RequestScoped per spec is available in all EJB invocations, 
all @PostConstruct CDI methods (which could be an @Named Batchlet, Reader, 
Writer, …), Message Driven Beans, JAX-RS and JAX-WS invocations, @Remote 
invocations, etc. 

So despite it originates from ServletRequests it is really much more like a 
„@ThreadScoped“ actually. And that’s the reason why it is so tremendously 
popular.

If I write something which is purely used in batches, then I’d also prefer 
@StepScoped. 
BUT if you need to reuse some Service which is e.g. also used in MDBs and 
Servlet invocations (JSF, etc) then @RequestScoped is the best you can do to 
store information which is not shared across different threads.

LieGrue,
strub




> Am 04.03.2015 um 13:23 schrieb Romain Manni-Bucau <[email protected]>:
> 
> @Mark: this has no link with EE 6 or 7, this is just a feature you want - 
> which is fine. JBatch doesn't deal with request scoped at all for instance. 
> That said for batches we have @JobScoped and @StepScoped which are still 
> exeprimental in batchee-cdi but can be more adapted. I know you are used to 
> it but I just find it a non-sense to have named request scoped something 
> which is not bound to any http request but that's another topic ;)
> 
> 
> Romain Manni-Bucau
> @rmannibucau |  Blog | Github | LinkedIn | Tomitriber
> 
> 2015-03-04 13:11 GMT+01:00 Mark Struberg <[email protected]>:
> I did not read the full thread, but @Stateless and a @RequestScoped 
> EntityManager doesn’t make sense.
> @Stateless basically _only_ works well with @PersistenceContext. If you use 
> DeltaSpike JPA then I’d rather use @AppliationScoped + @Transactional (from 
> deltaspike, not the half-broken one from EE7).
> 
> 
> The EE support module btw is not just for WAS - it’s for all environments 
> which support EE but not yet EE7. The point is that with wrapping new thread 
> creating in @Asynchronous ejb call you get all the ThreadLocals set up for 
> free. And it’s even needed on some EE7 container as the concurrency-utils 
> spec doesn’t define that the Context for @RequestScoped needs to get started. 
> Some containers do it, others don’t…
> 
> LieGrue,
> strub
> 
> 
> 
> > Am 02.03.2015 um 22:46 schrieb Romain Manni-Bucau <[email protected]>:
> >
> > Depend your conf for both but a thread stack will say you in 2s
> >
> > Le 2 mars 2015 22:35, <[email protected]> a écrit :
> > Hrmm. Probably not. But maybe, I would expect a clear error message though? 
> > Maybe some other pool like stateless? Or will it get tired of waiting and 
> > throw?
> >
> > Skickat från min iPhone
> >
> > 2 mar 2015 kl. 21:58 skrev Romain Manni-Bucau <[email protected]>:
> >
> >> Full db connection pool?
> >>
> >> Le 2 mars 2015 21:04, "Karl Kildén" <[email protected]> a écrit :
> >> Hi Romain, I removed all @Async usage and now it's the request thread that 
> >> hangs :D
> >>
> >> Actually when I dump the thread it seems to work forever being here and 
> >> there inside Eclipselink internals. Wonder if I triggered some kind of 
> >> endless loop. It looks like it because my heap is going way up and down 
> >> and I am the only one using the app and whatever task I started should be 
> >> done aaaages ago.
> >>
> >> Big help getting my attention away from batch and async :-)
> >>
> >> I will keep analyzing. If it's not local to my app I will try to reproduce 
> >> it in a sample (but it's always quite hard to do that :/)
> >>
> >> thanks again
> >>
> >>
> >>
> >> On 2 March 2015 at 20:07, Romain Manni-Bucau <[email protected]> wrote:
> >> yes surely
> >>
> >> if you can put some effort to create a github project it can really help 
> >> since we'll identify the issue really faster (and where it comes from ;))
> >>
> >>
> >> Romain Manni-Bucau
> >> @rmannibucau |  Blog | Github | LinkedIn | Tomitriber
> >>
> >> 2015-03-02 19:32 GMT+01:00 Karl Kildén <[email protected]>:
> >> Romain you are right I am to tired now... Maybe I am quite stupid for 
> >> putting @RequestScoped on it since that is how I used to do it when I did 
> >> tomcat.  It should not even do anything when I think about it.
> >>
> >> This problem seems very related to how I use @Async. Maybe I should move 
> >> my topic with a new mail to tomee list?
> >>
> >> On 2 March 2015 at 19:27, Romain Manni-Bucau <[email protected]> wrote:
> >> well
> >>
> >> deltaspike data doesn't want @RequestScoped, it just used the contextual 
> >> entity manager - this comes from what JSF guys do AFAIK.
> >>
> >> Wonder if you could reproduce it with OpenJPA or if it is due to the fact 
> >> eclipselink is storing itself a state somewhere. Any idea?
> >>
> >>
> >>
> >> Romain Manni-Bucau
> >> @rmannibucau |  Blog | Github | LinkedIn | Tomitriber
> >>
> >> 2015-03-02 19:13 GMT+01:00 Karl Kildén <[email protected]>:
> >> Romain,
> >>
> >> Deltaspike Data wants a @RequestScoped entityManager. If I want to use 
> >> Data module from my batches, how to combine that?
> >>
> >> Also, this whole problem seems linked to @Async not batch (I thought batch 
> >> was implemented with @Async)
> >>
> >> On 2 March 2015 at 18:50, Romain Manni-Bucau <[email protected]> wrote:
> >> batchee default impl shouldnt be @Async excepted if you imported the 
> >> module Mark added for WAS - but your thread naming is closer to tomee ;).
> >>
> >> batches are by design asynchronous so no need of @Async to launch them.
> >>
> >> then all depends your @requestScoped. if it matches nothing the container 
> >> handles (http request or synchronous ejb call) then you should handle it 
> >> yourself but sounds like a workaround more than a fix which would be using 
> >> a correct scope.
> >>
> >>
> >>
> >> Romain Manni-Bucau
> >> @rmannibucau |  Blog | Github | LinkedIn | Tomitriber
> >>
> >> 2015-03-02 18:44 GMT+01:00 Karl Kildén <[email protected]>:
> >> I was wrong - this problem is in many other places not just batches!
> >>
> >> regarding batch:
> >>
> >> Interesting, I have not done anything (what I know) to enable 
> >> requestscoped...
> >>
> >> I thought Mark once told me that the impl in batchee for creating threads 
> >> is actually @Asynchronous. I also kind of recall not getting any extra 
> >> threads in my batchee jobs until I increased the @Async thread pool.
> >>
> >> I do use @Async myself also here and there... In fact I think in one or 
> >> two cases Asynchronous will start the batch. I use 
> >> <class>org.apache.deltaspike.jpa.impl.transaction.EnvironmentAwareTransactionStrategy</class>
> >>
> >> Then I use this producer:
> >>
> >>      @PersistenceContext(unitName = APP_NAME)
> >>      private EntityManager entityManager;
> >>
> >>      @Produces
> >>      @RequestScoped
> >>      protected EntityManager createEntityManager() {
> >>              return this.entityManager;
> >>      }
> >>
> >>
> >>
> >> And a normal stateless that uses either the entityManager or a repository 
> >> from deltaspike data (actually almost always the repository). This is the 
> >> only way I produce entityManagers.
> >>
> >>
> >> Anyways my problem seems to be also in JSF @ViewScoped beans and whatnot. 
> >> Can it be that I must dispose my entitymanagers myself somehow?
> >>
> >>
> >>
> >> On 2 March 2015 at 18:15, Romain Manni-Bucau <[email protected]> wrote:
> >> Hmm
> >>
> >> for a batch this code doesnt mean anything - request scope. Did you hack 
> >> something around detaspike to make it working?
> >>
> >> If this entity manager is used in an EJB this should be fine, if not then 
> >> you need to ensure transaction are handled as you expect - should be the 
> >> case with batchee but doesnt cost anything to validate it .
> >>
> >> Finally do you use @Asynchronous in your code otherwise you shouldn't see 
> >> it
> >>
> >>
> >>
> >>
> >>
> >> Romain Manni-Bucau
> >> @rmannibucau |  Blog | Github | LinkedIn | Tomitriber
> >>
> >> 2015-03-02 18:10 GMT+01:00 Karl Kildén <[email protected]>:
> >> Hello,
> >>
> >> I have some @Stateless that I use from batches. After the job has finished 
> >> I can see after a heap dump that the async thread seems to keep a 
> >> reference to the RepeatableWriteUnitOfWork. When I google I understand 
> >> that this is the EclipseLink entitymanager and since nobody seems to have 
> >> called clear on it my heap is getting pretty full...
> >>
> >> I have defined my Batches with normal read process write. They are @Named 
> >> and simply inject my @Stateless. They @Stateless uses EntityManager and it 
> >> is produced like this:
> >>
> >>      @PersistenceContext(unitName = APP_NAME)
> >>      private EntityManager entityManager;
> >>
> >>      @Produces
> >>      @RequestScoped
> >>      protected EntityManager createEntityManager() {
> >>              return this.entityManager;
> >>      }
> >>
> >>
> >> Not sure if I am missing some kind of disposal here?  I don't think so 
> >> because only the jobs get the UnitOfWork stuck on the heap.
> >>
> >> Not sure I understand any of this very well. I can just clearly see that 
> >> my entire heap is now RepeatableWriteUnitOfWork tied to @ASynchronous 
> >> threads.
> >>
> >> My memory dump could of course be sent to someone or shared desktop if 
> >> someone want's to help me understand this... Or maybe a pointer on where 
> >> to debug?
> >>
> >> cheers
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> 
> 

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