Bojan Dolinar [http://community.jboss.org/people/bodzolca] created the 
discussion

"How to reconcile CMPC and SMPC?"

To view the discussion, visit: http://community.jboss.org/message/611536#611536

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When using EJB and Seam, it's probably inevitable to end up with lots of EJBs 
that are components at the same time, some with container-managed persistent 
context, some with SMPC. Because it was easier to do (mostly since it precludes 
any kind of LazyInitializationException) our codebase ended up with lots of 
EJBs/components with SMPC, even the ones that are part of the data engine and 
are not always part of the JSF lifecycle (triggered jobs, WS, other services, 
etc.). The absence of this lifecycle is probably the reason for some strange 
behaviour since it's not clear what the session is scoped to. For example, 
sometimes the actionqueue just doesn't get cleaned up after commit, so 
performance of a job degrades quickly (every flush "flushes" every preceding 
change), not to mention the memory leak. Migration from Seam 2.0.1 to 2.2.1 was 
the start of a whole new problem: org.hibernate.StaleStateException because 
optimistic locking failed. Looks like actionqueue again is keeping some stale 
objects and decides to commit them, quite sporadically, for all I could find 
out.

I guess that in the absence of conversation the session doesn't get closed. The 
situation is alleviated by superseding SMPC with @PersistenceContext. But due 
to convoluted and numerous execution paths, I'm not allowed to even dream that 
I'm aware of all the side effects. LIE is just on the top of the list, because 
all the entities loaded by PC are detached sooner or later.

All this leads to two questions. First, what would be the best way to handle 
this situation? Is mocking the approapriate JSF life cycle phases safe? Is it 
possible to scope SMPC to transaction programmatically? 

Second, what is the best way to handle this situation from the scratch, when 
you have that luxury? I didn't find anything addressing this exact problem and 
I'm sure I'm not the only one experiencing it. My personal approach would be to 
keep the seam layer as thin as possible. When I was not restricted by legacy 
code, it worked quite well, although I had to think carefully about LIE all 
over again. However, every book I've read so far advocates the exact opposite 
approach. Their samples are usually pure web applications, but I was more than 
welcome to the real world.

Any thoughts or pointers to further reading on this would be appreciated.
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