RE: Exceptions thrown from callbacks

2007-02-06 Thread Patrick Linskey
It seems like we've reached consensus around the following behavior at
least:

1. if a callback throws an exception during commit(), wrap in
RollbackException and roll back the transaction.

2. if a callback throws an exception during some non-commit() operation,
do not wrap the exception, and mark the transaction for rollback.

It turns out that this is exactly the current behavior. I just checked
in some test cases to exercise this, since the CTS has an outage here
now.

-Patrick

-- 
Patrick Linskey
BEA Systems, Inc. 

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> -Original Message-
> From: Patrick Linskey 
> Sent: Thursday, February 01, 2007 3:27 PM
> To: open-jpa-dev@incubator.apache.org
> Subject: Exceptions thrown from callbacks
> 
> Hi,
> 
> There's a bit of ambiguity in the spec about what should 
> happen when an
> exception is thrown from a callback. 
> 
> I propose that we change OpenJPA's behavior to always wrap exceptions
> thrown from callbacks in a RollbackException. Additionally, I propose
> that if a callback is thrown from a direct flush() call or a find() or
> other data load, we should mark the transaction for rollback 
> instead of
> immediately rolling back the transaction.
> 
> 
> Details:
> 
> Section 3.5 says: 
> 
> "Lifecycle callback methods may throw unchecked/runtime exceptions. A
> runtime exception thrown by a callback method that executes within a
> transaction causes that transaction to be rolled back."
> 
> 3.5.6: 
> 
> "Lifecycle callback methods may throw runtime exceptions. A runtime
> exception thrown by a callback method that executes within a 
> transaction
> causes that transaction to be rolled back. No further 
> lifecycle callback
> methods will be invoked after a runtime exception is thrown."
> 
> 3.7:
> 
> "The PersistenceException is thrown by the persistence provider when a
> problem occurs. [...] All instances of PersistenceException except for
> instances of NoResultException and NonUniqueResultException will cause
> the current transaction, if one is active, to be marked for rollback."
> 
> ...
> 
> "The RollbackException is thrown by the persistence provider when
> EntityTransaction.commit() fails.
> 
> 
> So in my opinion, this means that if a callback fails during
> commit(), the exception thrown by the callback clearly should 
> be wrapped
> in a RollbackException. It is less clear to me what should happen if a
> callback fails at some other time, such as during a find() call. In my
> opinion, we should be wrapping the user-thrown exceptions in
> RollbackExceptions all the time.
> 
> Further, I think that 3.7 trumps 3.5.6, so if an exception is thrown
> from a callback during a find(), we should be marking the transaction
> for rollback, rather than actually rolling it back.
> 
> I've got changes in place that implement the behavior I just 
> described.
> The CTS tests surrounding this issue have been excluded, due to the
> ambiguity in the spec.
> 
> Thoughts?
> 
> -Patrick
> 
> -- 
> Patrick Linskey
> BEA Systems, Inc. 
> 
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Re: Exceptions thrown from callbacks

2007-02-06 Thread Craig L Russell

Ah, the perils of spec-writing...

On Feb 1, 2007, at 3:55 PM, Dain Sundstrom wrote:


On Feb 1, 2007, at 3:27 PM, Patrick Linskey wrote:


3.5.6:

"Lifecycle callback methods may throw runtime exceptions. A runtime
exception thrown by a callback method that executes within a  
transaction
causes that transaction to be rolled back. No further lifecycle  
callback

methods will be invoked after a runtime exception is thrown."


One other thing to check is if the tx is marked rollback only,  
should we not call anymore lifecycle events or is that "No Further  
lifecycle callback" clause supposed to apply to the single entity  
that failed.


More decisions. Is it

1. After a runtime exception is thrown (during any em method call)  
the tx is marked for rollback and no callbacks are called on any  
entity for any method


2. After a runtime exception is thrown from a user-defined callback,  
the tx is marked for rollback and no callbacks are called on any  
entity for any method


3. After a runtime exception is thrown from a user-defined callback,  
the tx is marked for rollback and no callbacks are called on the  
entity that stimulated the exception


4. After a runtime exception is thrown from a user-defined callback,  
the tx is marked for rollback and no callbacks are called on any  
entity during the execution of the current entity manager method


5. The provider decides what to do

6. Something else

Craig Russell
DB PMC
[EMAIL PROTECTED] http://db.apache.org/jdo




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Description: S/MIME cryptographic signature


Re: Exceptions thrown from callbacks

2007-02-06 Thread Abe White
I think if a user throws an exception in a callback outside of a  
commit operation, we should simply rethrow it to the user after we  
clean up our internal state. Presumably, the specific runtime  
exception has meaning to the user's code, and we don't add much  
value in wrapping the exception.


I might think differently if the spec allowed/required us to  
continue after catching the first exception thrown from a callback,  
but it explicitly says that the first exception aborts the  
operation. From 3.5.6,  "No further lifecycle callback methods will  
be invoked after a runtime exception is thrown."


I can go either way on it, but I think Craig's reasoning is sound.
+1
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RE: Exceptions thrown from callbacks

2007-02-06 Thread Patrick Linskey
> We should ask that the spec be clarified so applications can be more  
> portable.

I've done this, and have been told that this issue will be included in
the JPA 2.0 process.

-Patrick

-- 
Patrick Linskey
BEA Systems, Inc. 

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> -Original Message-
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] 
> Sent: Tuesday, February 06, 2007 12:12 PM
> To: open-jpa-dev@incubator.apache.org
> Subject: Re: Exceptions thrown from callbacks
> 
> 
> On Feb 6, 2007, at 11:27 AM, Patrick Linskey wrote:
> 
> > Out-of-band, Abe pointed out to me that the text about when
> > RollbackExceptions are thrown is pretty clear. 3.7 says:
> >
> > "The RollbackException is thrown by the persistence provider when
> > EntityTransaction.commit fails."
> >
> > So, it would seem that in the case where an EM.find() or some other
> > non-commit() call triggers a callback that throws an exception, we
> > should not wrap the exception in a RollbackException. Should we just
> > throw the raw exception, or should we wrap in some other
> > PersistenceException?
> 
> I think if a user throws an exception in a callback outside of a  
> commit operation, we should simply rethrow it to the user after we  
> clean up our internal state. Presumably, the specific runtime  
> exception has meaning to the user's code, and we don't add 
> much value  
> in wrapping the exception.
> 
> I might think differently if the spec allowed/required us to 
> continue  
> after catching the first exception thrown from a callback, but it  
> explicitly says that the first exception aborts the operation. From  
> 3.5.6,  "No further lifecycle callback methods will be invoked after  
> a runtime exception is thrown."
> 
>  From that same paragraph, "A runtime exception thrown by a callback  
> method that executes within a transaction causes that transaction to  
> be rolled back." But I think it's ok to set RollbackOnly to satisfy  
> this requirement. And as a matter of design (separation of concerns)  
> this really is best practice.
> 
> We should ask that the spec be clarified so applications can be more  
> portable.
> 
> Craig
> >
> > -Patrick
> >
> > -- 
> > Patrick Linskey
> > BEA Systems, Inc.
> >
> > 
> __
>  
> > _
> > Notice:  This email message, together with any attachments, may  
> > contain
> > information  of  BEA Systems,  Inc.,  its subsidiaries  and   
> > affiliated
> > entities,  that may be confidential,  proprietary,  copyrighted   
> > and/or
> > legally privileged, and is intended solely for the use of the  
> > individual
> > or entity named in this message. If you are not the intended  
> > recipient,
> > and have received this message in error, please immediately return  
> > this
> > by email and then delete it.
> >
> >> -Original Message-
> >> From: Patrick Linskey [mailto:[EMAIL PROTECTED]
> >> Sent: Monday, February 05, 2007 7:14 PM
> >> To: open-jpa-dev@incubator.apache.org
> >> Subject: RE: Exceptions thrown from callbacks
> >>
> >>>> I don't recall the details about why we made that
> >> decision, but I
> >>>> prefer
> >>>> wrapping in a RollbackException for consistency. It sucks
> >> to have
> >>>> to do:
> >>>
> >>> I agree that that sucks. Of course, if they want their
> >>> application to
> >>> be portable, then they'll need to put in that logic anyway :)
> >>
> >> Agreed, and we may need to change our behavior later once the
> >> spec team
> >> clears this up. I'll be lobbying for the spec team to move to the
> >> always-wrapped model, though.
> >>
> >>>> Do you have any opinion about the rollback vs. mark-for-rollback
> >>>> distinction?
> >>>
> >>> Well, section

Re: Exceptions thrown from callbacks

2007-02-06 Thread Craig L Russell


On Feb 6, 2007, at 11:27 AM, Patrick Linskey wrote:


Out-of-band, Abe pointed out to me that the text about when
RollbackExceptions are thrown is pretty clear. 3.7 says:

"The RollbackException is thrown by the persistence provider when
EntityTransaction.commit fails."

So, it would seem that in the case where an EM.find() or some other
non-commit() call triggers a callback that throws an exception, we
should not wrap the exception in a RollbackException. Should we just
throw the raw exception, or should we wrap in some other
PersistenceException?


I think if a user throws an exception in a callback outside of a  
commit operation, we should simply rethrow it to the user after we  
clean up our internal state. Presumably, the specific runtime  
exception has meaning to the user's code, and we don't add much value  
in wrapping the exception.


I might think differently if the spec allowed/required us to continue  
after catching the first exception thrown from a callback, but it  
explicitly says that the first exception aborts the operation. From  
3.5.6,  "No further lifecycle callback methods will be invoked after  
a runtime exception is thrown."


From that same paragraph, "A runtime exception thrown by a callback  
method that executes within a transaction causes that transaction to  
be rolled back." But I think it's ok to set RollbackOnly to satisfy  
this requirement. And as a matter of design (separation of concerns)  
this really is best practice.


We should ask that the spec be clarified so applications can be more  
portable.


Craig


-Patrick

--
Patrick Linskey
BEA Systems, Inc.

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-Original Message-
From: Patrick Linskey [mailto:[EMAIL PROTECTED]
Sent: Monday, February 05, 2007 7:14 PM
To: open-jpa-dev@incubator.apache.org
Subject: RE: Exceptions thrown from callbacks


I don't recall the details about why we made that

decision, but I

prefer
wrapping in a RollbackException for consistency. It sucks

to have

to do:


I agree that that sucks. Of course, if they want their
application to
be portable, then they'll need to put in that logic anyway :)


Agreed, and we may need to change our behavior later once the
spec team
clears this up. I'll be lobbying for the spec team to move to the
always-wrapped model, though.


Do you have any opinion about the rollback vs. mark-for-rollback
distinction?


Well, section 3.5 suggests that it should be rolled back
immediately,
but then if we start wrapping in a PersistenceException, then 3.7
says that it should just be marked for rollback. Tricky. I guess I
favor immediate rollback, just since section 3.5 is so explicit in
saying that it should happen.


I think that rolling back directly is pretty evil, and as I
recall, the
spec team agreed at one point. I think that this one just slipped
through the cracks. In any event, this is covered in the area
of the CTS
that was excluded, for just this reason presumably.

--
Patrick Linskey
BEA Systems, Inc.

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-Original Message-
From: Marc Prud'hommeaux [mailto:[EMAIL PROTECTED] On
Behalf Of Marc Prud'hommeaux
Sent: Monday, February 05, 2007 6:49 PM
To: open-jpa-dev@incubator.apache.org
Subject: Re: Exceptions thrown from callbacks




I don't recall the details about why we made that

decision, but I

prefer
wrapping in a RollbackException for consistency. It sucks

to have

to do:


I agree that that sucks. Of course, if they want their
application to
be portable, then they'll need to put in that logic anyway :)


Do you have any opinion about the rollback vs. mark-for-rollback
distinction?


Well, section 3.5 suggests that it should be rolled back
immediately,
but then if we start wrapping in a PersistenceException, then 3.7
says that it should just be marked for rollback. Tricky. I guess I
favor immediate rollback, just since section 3.5 is so 

RE: Exceptions thrown from callbacks

2007-02-06 Thread Patrick Linskey
Out-of-band, Abe pointed out to me that the text about when
RollbackExceptions are thrown is pretty clear. 3.7 says:

"The RollbackException is thrown by the persistence provider when
EntityTransaction.commit fails."

So, it would seem that in the case where an EM.find() or some other
non-commit() call triggers a callback that throws an exception, we
should not wrap the exception in a RollbackException. Should we just
throw the raw exception, or should we wrap in some other
PersistenceException?

-Patrick

-- 
Patrick Linskey
BEA Systems, Inc. 

___
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or entity named in this message. If you are not the intended recipient,
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> -Original Message-
> From: Patrick Linskey [mailto:[EMAIL PROTECTED] 
> Sent: Monday, February 05, 2007 7:14 PM
> To: open-jpa-dev@incubator.apache.org
> Subject: RE: Exceptions thrown from callbacks
> 
> > > I don't recall the details about why we made that 
> decision, but I  
> > > prefer
> > > wrapping in a RollbackException for consistency. It sucks 
> to have  
> > > to do:
> > 
> > I agree that that sucks. Of course, if they want their 
> > application to  
> > be portable, then they'll need to put in that logic anyway :)
> 
> Agreed, and we may need to change our behavior later once the 
> spec team
> clears this up. I'll be lobbying for the spec team to move to the
> always-wrapped model, though.
> 
> > > Do you have any opinion about the rollback vs. mark-for-rollback  
> > > distinction?
> > 
> > Well, section 3.5 suggests that it should be rolled back 
> > immediately,  
> > but then if we start wrapping in a PersistenceException, then 3.7  
> > says that it should just be marked for rollback. Tricky. I guess I  
> > favor immediate rollback, just since section 3.5 is so explicit in  
> > saying that it should happen.
> 
> I think that rolling back directly is pretty evil, and as I 
> recall, the
> spec team agreed at one point. I think that this one just slipped
> through the cracks. In any event, this is covered in the area 
> of the CTS
> that was excluded, for just this reason presumably.
> 
> -- 
> Patrick Linskey
> BEA Systems, Inc. 
> 
> __
> _
> Notice:  This email message, together with any attachments, 
> may contain
> information  of  BEA Systems,  Inc.,  its subsidiaries  and  
> affiliated
> entities,  that may be confidential,  proprietary,  
> copyrighted  and/or
> legally privileged, and is intended solely for the use of the 
> individual
> or entity named in this message. If you are not the intended 
> recipient,
> and have received this message in error, please immediately 
> return this
> by email and then delete it. 
> 
> > -Original Message-
> > From: Marc Prud'hommeaux [mailto:[EMAIL PROTECTED] On 
> > Behalf Of Marc Prud'hommeaux
> > Sent: Monday, February 05, 2007 6:49 PM
> > To: open-jpa-dev@incubator.apache.org
> > Subject: Re: Exceptions thrown from callbacks
> > 
> > 
> > 
> > > I don't recall the details about why we made that 
> decision, but I  
> > > prefer
> > > wrapping in a RollbackException for consistency. It sucks 
> to have  
> > > to do:
> > 
> > I agree that that sucks. Of course, if they want their 
> > application to  
> > be portable, then they'll need to put in that logic anyway :)
> > 
> > > Do you have any opinion about the rollback vs. mark-for-rollback  
> > > distinction?
> > 
> > Well, section 3.5 suggests that it should be rolled back 
> > immediately,  
> > but then if we start wrapping in a PersistenceException, then 3.7  
> > says that it should just be marked for rollback. Tricky. I guess I  
> > favor immediate rollback, just since section 3.5 is so explicit in  
> > saying that it should happen.
> > 
> > 
> > 
> > On Feb 5, 2007, at 6:27 PM, Patrick Linskey wrote:
> > 
> > >> As for whether to wrap the exceptions during 
> non-flush/commit times
> > >> (e.g., during a find() call), I'm a little less keen on 
> it, but not
> > >> r

Re: Exceptions thrown from callbacks

2007-02-06 Thread Craig L Russell


On Feb 5, 2007, at 7:14 PM, Patrick Linskey wrote:


Do you have any opinion about the rollback vs. mark-for-rollback
distinction?


Well, section 3.5 suggests that it should be rolled back
immediately,
but then if we start wrapping in a PersistenceException, then 3.7
says that it should just be marked for rollback. Tricky. I guess I
favor immediate rollback, just since section 3.5 is so explicit in
saying that it should happen.


I think that rolling back directly is pretty evil, and as I recall,  
the

spec team agreed at one point. I think that this one just slipped
through the cracks. In any event, this is covered in the area of  
the CTS

that was excluded, for just this reason presumably.


If you get the exception in a commit, then it's appropriate to roll  
back immediately. If you get the exception anywhere else, I'm  
strongly opposed to an immediate rollback. Mark the transaction for  
rollback is the appropriate action.


Craig


--
Patrick Linskey
BEA Systems, Inc.

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and have received this message in error, please immediately return  
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-Original Message-
From: Marc Prud'hommeaux [mailto:[EMAIL PROTECTED] On
Behalf Of Marc Prud'hommeaux
Sent: Monday, February 05, 2007 6:49 PM
To: open-jpa-dev@incubator.apache.org
Subject: Re: Exceptions thrown from callbacks




I don't recall the details about why we made that decision, but I
prefer
wrapping in a RollbackException for consistency. It sucks to have
to do:


I agree that that sucks. Of course, if they want their
application to
be portable, then they'll need to put in that logic anyway :)


Do you have any opinion about the rollback vs. mark-for-rollback
distinction?


Well, section 3.5 suggests that it should be rolled back
immediately,
but then if we start wrapping in a PersistenceException, then 3.7
says that it should just be marked for rollback. Tricky. I guess I
favor immediate rollback, just since section 3.5 is so explicit in
saying that it should happen.



On Feb 5, 2007, at 6:27 PM, Patrick Linskey wrote:


As for whether to wrap the exceptions during non-flush/commit times
(e.g., during a find() call), I'm a little less keen on it, but not
really opposed. The reason is that the clause "Lifecycle callback
methods may throw runtime exceptions" suggests to me (and,
apparently, to the CTS authors) that they restricted the exception
type to be runtime exceptions because they expect the unmodified
exception will be thrown straight up the application. Summary: +0


I don't recall the details about why we made that decision, but I
prefer
wrapping in a RollbackException for consistency. It sucks to have
to do:

try {
em.find(...);
em.commit();
} catch (RollbackException re) {
if (re.getCause() instanceof MySpecialException) {
// custom logic
} else {
throw re;
}
} catch (MySpecialException mse) {
// same custom logic as above
}


Do you have any opinion about the rollback vs. mark-for-rollback
distinction?

-Patrick

--
Patrick Linskey
BEA Systems, Inc.



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-Original Message-
From: Marc Prud'hommeaux [mailto:[EMAIL PROTECTED] On
Behalf Of Marc Prud'hommeaux
Sent: Monday, February 05, 2007 6:20 PM
To: open-jpa-dev@incubator.apache.org
Subject: Re: Exceptions thrown from callbacks


I don't have any strong opinions either way. Wrapping is useful,
because we can usually provide the FailedObject so that

the user can

more easily attempt some recovery. And I do agree that if

a callback

exception occurs during a commit()/flush() operation then we should
wrap it (and it might as well be in a RollbackException).

Summary: +1


As for whether to wrap the exceptions during non-flush/commit times
(e.g., during a find() call), I'm a little less keen on it, but not
really opposed. The reason is that the clause "Lifecycle callback
methods may throw runtime exceptions" suggests to me (and,
apparently, to the CTS author

RE: Exceptions thrown from callbacks

2007-02-05 Thread Patrick Linskey
> > I don't recall the details about why we made that decision, but I  
> > prefer
> > wrapping in a RollbackException for consistency. It sucks to have  
> > to do:
> 
> I agree that that sucks. Of course, if they want their 
> application to  
> be portable, then they'll need to put in that logic anyway :)

Agreed, and we may need to change our behavior later once the spec team
clears this up. I'll be lobbying for the spec team to move to the
always-wrapped model, though.

> > Do you have any opinion about the rollback vs. mark-for-rollback  
> > distinction?
> 
> Well, section 3.5 suggests that it should be rolled back 
> immediately,  
> but then if we start wrapping in a PersistenceException, then 3.7  
> says that it should just be marked for rollback. Tricky. I guess I  
> favor immediate rollback, just since section 3.5 is so explicit in  
> saying that it should happen.

I think that rolling back directly is pretty evil, and as I recall, the
spec team agreed at one point. I think that this one just slipped
through the cracks. In any event, this is covered in the area of the CTS
that was excluded, for just this reason presumably.

-- 
Patrick Linskey
BEA Systems, Inc. 

___
Notice:  This email message, together with any attachments, may contain
information  of  BEA Systems,  Inc.,  its subsidiaries  and  affiliated
entities,  that may be confidential,  proprietary,  copyrighted  and/or
legally privileged, and is intended solely for the use of the individual
or entity named in this message. If you are not the intended recipient,
and have received this message in error, please immediately return this
by email and then delete it. 

> -Original Message-
> From: Marc Prud'hommeaux [mailto:[EMAIL PROTECTED] On 
> Behalf Of Marc Prud'hommeaux
> Sent: Monday, February 05, 2007 6:49 PM
> To: open-jpa-dev@incubator.apache.org
> Subject: Re: Exceptions thrown from callbacks
> 
> 
> 
> > I don't recall the details about why we made that decision, but I  
> > prefer
> > wrapping in a RollbackException for consistency. It sucks to have  
> > to do:
> 
> I agree that that sucks. Of course, if they want their 
> application to  
> be portable, then they'll need to put in that logic anyway :)
> 
> > Do you have any opinion about the rollback vs. mark-for-rollback  
> > distinction?
> 
> Well, section 3.5 suggests that it should be rolled back 
> immediately,  
> but then if we start wrapping in a PersistenceException, then 3.7  
> says that it should just be marked for rollback. Tricky. I guess I  
> favor immediate rollback, just since section 3.5 is so explicit in  
> saying that it should happen.
> 
> 
> 
> On Feb 5, 2007, at 6:27 PM, Patrick Linskey wrote:
> 
> >> As for whether to wrap the exceptions during non-flush/commit times
> >> (e.g., during a find() call), I'm a little less keen on it, but not
> >> really opposed. The reason is that the clause "Lifecycle callback
> >> methods may throw runtime exceptions" suggests to me (and,
> >> apparently, to the CTS authors) that they restricted the exception
> >> type to be runtime exceptions because they expect the unmodified
> >> exception will be thrown straight up the application. Summary: +0
> >
> > I don't recall the details about why we made that decision, but I  
> > prefer
> > wrapping in a RollbackException for consistency. It sucks to have  
> > to do:
> >
> > try {
> > em.find(...);
> > em.commit();
> > } catch (RollbackException re) {
> > if (re.getCause() instanceof MySpecialException) {
> > // custom logic
> > } else {
> > throw re;
> > }
> > } catch (MySpecialException mse) {
> > // same custom logic as above
> > }
> >
> >
> > Do you have any opinion about the rollback vs. mark-for-rollback
> > distinction?
> >
> > -Patrick
> >
> > -- 
> > Patrick Linskey
> > BEA Systems, Inc.
> >
> > 
> __
>  
> > _
> > Notice:  This email message, together with any attachments, may  
> > contain
> > information  of  BEA Systems,  Inc.,  its subsidiaries  and   
> > affiliated
> > entities,  that may be confidential,  proprietary,  copyrighted   
> > and/or
> > legally privileged, and is intended solely for the use of the  
> > individual
> > or entity named in this message. If you are not the intended  
> > recipient,
> > and ha

Re: Exceptions thrown from callbacks

2007-02-05 Thread Marc Prud'hommeaux



I don't recall the details about why we made that decision, but I  
prefer
wrapping in a RollbackException for consistency. It sucks to have  
to do:


I agree that that sucks. Of course, if they want their application to  
be portable, then they'll need to put in that logic anyway :)


Do you have any opinion about the rollback vs. mark-for-rollback  
distinction?


Well, section 3.5 suggests that it should be rolled back immediately,  
but then if we start wrapping in a PersistenceException, then 3.7  
says that it should just be marked for rollback. Tricky. I guess I  
favor immediate rollback, just since section 3.5 is so explicit in  
saying that it should happen.




On Feb 5, 2007, at 6:27 PM, Patrick Linskey wrote:


As for whether to wrap the exceptions during non-flush/commit times
(e.g., during a find() call), I'm a little less keen on it, but not
really opposed. The reason is that the clause "Lifecycle callback
methods may throw runtime exceptions" suggests to me (and,
apparently, to the CTS authors) that they restricted the exception
type to be runtime exceptions because they expect the unmodified
exception will be thrown straight up the application. Summary: +0


I don't recall the details about why we made that decision, but I  
prefer
wrapping in a RollbackException for consistency. It sucks to have  
to do:


try {
em.find(...);
em.commit();
} catch (RollbackException re) {
if (re.getCause() instanceof MySpecialException) {
// custom logic
} else {
throw re;
}
} catch (MySpecialException mse) {
// same custom logic as above
}


Do you have any opinion about the rollback vs. mark-for-rollback
distinction?

-Patrick

--
Patrick Linskey
BEA Systems, Inc.

__ 
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by email and then delete it.


-Original Message-
From: Marc Prud'hommeaux [mailto:[EMAIL PROTECTED] On
Behalf Of Marc Prud'hommeaux
Sent: Monday, February 05, 2007 6:20 PM
To: open-jpa-dev@incubator.apache.org
Subject: Re: Exceptions thrown from callbacks


I don't have any strong opinions either way. Wrapping is useful,
because we can usually provide the FailedObject so that the user can
more easily attempt some recovery. And I do agree that if a callback
exception occurs during a commit()/flush() operation then we should
wrap it (and it might as well be in a RollbackException). Summary: +1

As for whether to wrap the exceptions during non-flush/commit times
(e.g., during a find() call), I'm a little less keen on it, but not
really opposed. The reason is that the clause "Lifecycle callback
methods may throw runtime exceptions" suggests to me (and,
apparently, to the CTS authors) that they restricted the exception
type to be runtime exceptions because they expect the unmodified
exception will be thrown straight up the application. Summary: +0




On Feb 1, 2007, at 3:27 PM, Patrick Linskey wrote:


Hi,

There's a bit of ambiguity in the spec about what should happen
when an
exception is thrown from a callback.

I propose that we change OpenJPA's behavior to always wrap

exceptions

thrown from callbacks in a RollbackException. Additionally,

I propose

that if a callback is thrown from a direct flush() call or

a find() or

other data load, we should mark the transaction for rollback
instead of
immediately rolling back the transaction.


Details:

Section 3.5 says:

"Lifecycle callback methods may throw unchecked/runtime

exceptions. A

runtime exception thrown by a callback method that executes within a
transaction causes that transaction to be rolled back."

3.5.6:

"Lifecycle callback methods may throw runtime exceptions. A runtime
exception thrown by a callback method that executes within a
transaction
causes that transaction to be rolled back. No further lifecycle
callback
methods will be invoked after a runtime exception is thrown."

3.7:

"The PersistenceException is thrown by the persistence

provider when a

problem occurs. [...] All instances of PersistenceException

except for

instances of NoResultException and NonUniqueResultException

will cause

the current transaction, if one is active, to be marked for

rollback."


...

"The RollbackException is thrown by the persistence provider when
EntityTransaction.commit() fails.


So in my opinion, this means that if a callback fails during
commit(), the exception thrown by the callback clearly should be
wrapped
i

RE: Exceptions thrown from callbacks

2007-02-05 Thread Patrick Linskey
> As for whether to wrap the exceptions during non-flush/commit times  
> (e.g., during a find() call), I'm a little less keen on it, but not  
> really opposed. The reason is that the clause "Lifecycle callback  
> methods may throw runtime exceptions" suggests to me (and,  
> apparently, to the CTS authors) that they restricted the exception  
> type to be runtime exceptions because they expect the unmodified  
> exception will be thrown straight up the application. Summary: +0

I don't recall the details about why we made that decision, but I prefer
wrapping in a RollbackException for consistency. It sucks to have to do:

try {
em.find(...);
em.commit();
} catch (RollbackException re) {
if (re.getCause() instanceof MySpecialException) {
// custom logic
} else {
throw re;
}
} catch (MySpecialException mse) {
// same custom logic as above
}


Do you have any opinion about the rollback vs. mark-for-rollback
distinction?

-Patrick

-- 
Patrick Linskey
BEA Systems, Inc. 

___
Notice:  This email message, together with any attachments, may contain
information  of  BEA Systems,  Inc.,  its subsidiaries  and  affiliated
entities,  that may be confidential,  proprietary,  copyrighted  and/or
legally privileged, and is intended solely for the use of the individual
or entity named in this message. If you are not the intended recipient,
and have received this message in error, please immediately return this
by email and then delete it. 

> -Original Message-
> From: Marc Prud'hommeaux [mailto:[EMAIL PROTECTED] On 
> Behalf Of Marc Prud'hommeaux
> Sent: Monday, February 05, 2007 6:20 PM
> To: open-jpa-dev@incubator.apache.org
> Subject: Re: Exceptions thrown from callbacks
> 
> 
> I don't have any strong opinions either way. Wrapping is useful,  
> because we can usually provide the FailedObject so that the user can  
> more easily attempt some recovery. And I do agree that if a callback  
> exception occurs during a commit()/flush() operation then we should  
> wrap it (and it might as well be in a RollbackException). Summary: +1
> 
> As for whether to wrap the exceptions during non-flush/commit times  
> (e.g., during a find() call), I'm a little less keen on it, but not  
> really opposed. The reason is that the clause "Lifecycle callback  
> methods may throw runtime exceptions" suggests to me (and,  
> apparently, to the CTS authors) that they restricted the exception  
> type to be runtime exceptions because they expect the unmodified  
> exception will be thrown straight up the application. Summary: +0
> 
> 
> 
> 
> On Feb 1, 2007, at 3:27 PM, Patrick Linskey wrote:
> 
> > Hi,
> >
> > There's a bit of ambiguity in the spec about what should happen  
> > when an
> > exception is thrown from a callback.
> >
> > I propose that we change OpenJPA's behavior to always wrap 
> exceptions
> > thrown from callbacks in a RollbackException. Additionally, 
> I propose
> > that if a callback is thrown from a direct flush() call or 
> a find() or
> > other data load, we should mark the transaction for rollback  
> > instead of
> > immediately rolling back the transaction.
> >
> >
> > Details:
> >
> > Section 3.5 says:
> >
> > "Lifecycle callback methods may throw unchecked/runtime 
> exceptions. A
> > runtime exception thrown by a callback method that executes within a
> > transaction causes that transaction to be rolled back."
> >
> > 3.5.6:
> >
> > "Lifecycle callback methods may throw runtime exceptions. A runtime
> > exception thrown by a callback method that executes within a  
> > transaction
> > causes that transaction to be rolled back. No further lifecycle  
> > callback
> > methods will be invoked after a runtime exception is thrown."
> >
> > 3.7:
> >
> > "The PersistenceException is thrown by the persistence 
> provider when a
> > problem occurs. [...] All instances of PersistenceException 
> except for
> > instances of NoResultException and NonUniqueResultException 
> will cause
> > the current transaction, if one is active, to be marked for 
> rollback."
> >
> > ...
> >
> > "The RollbackException is thrown by the persistence provider when
> > EntityTransaction.commit() fails.
> >
> >
> > So in my opinion, this means that if a callback fails during
> > commit(), the exception thrown by the callback clearly should be  
> > wrapped
> > in a RollbackException. It is less clear to me what should

Re: Exceptions thrown from callbacks

2007-02-05 Thread Marc Prud'hommeaux


I don't have any strong opinions either way. Wrapping is useful,  
because we can usually provide the FailedObject so that the user can  
more easily attempt some recovery. And I do agree that if a callback  
exception occurs during a commit()/flush() operation then we should  
wrap it (and it might as well be in a RollbackException). Summary: +1


As for whether to wrap the exceptions during non-flush/commit times  
(e.g., during a find() call), I'm a little less keen on it, but not  
really opposed. The reason is that the clause "Lifecycle callback  
methods may throw runtime exceptions" suggests to me (and,  
apparently, to the CTS authors) that they restricted the exception  
type to be runtime exceptions because they expect the unmodified  
exception will be thrown straight up the application. Summary: +0





On Feb 1, 2007, at 3:27 PM, Patrick Linskey wrote:


Hi,

There's a bit of ambiguity in the spec about what should happen  
when an

exception is thrown from a callback.

I propose that we change OpenJPA's behavior to always wrap exceptions
thrown from callbacks in a RollbackException. Additionally, I propose
that if a callback is thrown from a direct flush() call or a find() or
other data load, we should mark the transaction for rollback  
instead of

immediately rolling back the transaction.


Details:

Section 3.5 says:

"Lifecycle callback methods may throw unchecked/runtime exceptions. A
runtime exception thrown by a callback method that executes within a
transaction causes that transaction to be rolled back."

3.5.6:

"Lifecycle callback methods may throw runtime exceptions. A runtime
exception thrown by a callback method that executes within a  
transaction
causes that transaction to be rolled back. No further lifecycle  
callback

methods will be invoked after a runtime exception is thrown."

3.7:

"The PersistenceException is thrown by the persistence provider when a
problem occurs. [...] All instances of PersistenceException except for
instances of NoResultException and NonUniqueResultException will cause
the current transaction, if one is active, to be marked for rollback."

...

"The RollbackException is thrown by the persistence provider when
EntityTransaction.commit() fails.


So in my opinion, this means that if a callback fails during
commit(), the exception thrown by the callback clearly should be  
wrapped

in a RollbackException. It is less clear to me what should happen if a
callback fails at some other time, such as during a find() call. In my
opinion, we should be wrapping the user-thrown exceptions in
RollbackExceptions all the time.

Further, I think that 3.7 trumps 3.5.6, so if an exception is thrown
from a callback during a find(), we should be marking the transaction
for rollback, rather than actually rolling it back.

I've got changes in place that implement the behavior I just  
described.

The CTS tests surrounding this issue have been excluded, due to the
ambiguity in the spec.

Thoughts?

-Patrick

--
Patrick Linskey
BEA Systems, Inc.

__ 
_
Notice:  This email message, together with any attachments, may  
contain
information  of  BEA Systems,  Inc.,  its subsidiaries  and   
affiliated
entities,  that may be confidential,  proprietary,  copyrighted   
and/or
legally privileged, and is intended solely for the use of the  
individual
or entity named in this message. If you are not the intended  
recipient,
and have received this message in error, please immediately return  
this

by email and then delete it.




RE: Exceptions thrown from callbacks

2007-02-01 Thread Patrick Linskey
> > 3.5.6:
> >
> > "Lifecycle callback methods may throw runtime exceptions. A runtime
> > exception thrown by a callback method that executes within a  
> > transaction
> > causes that transaction to be rolled back. No further lifecycle  
> > callback
> > methods will be invoked after a runtime exception is thrown."
> 
> One other thing to check is if the tx is marked rollback 
> only, should  
> we not call anymore lifecycle events or is that "NoFurther lifecycle  
> callback" clause supposed to apply to the single entity that failed.

You mean: if someone calls setRollbackOnly() and then calls flush(),
what should we do about the @PreUpdate callback? I don't have a strong
opinion either way. My read of the spec is that we should execute the
callback; callbacks should only be aborted if the exception is thrown
during a time when the callbacks would have otherwise been invoked.

> > Further, I think that 3.7 trumps 3.5.6, so if an exception is thrown
> > from a callback during a find(), we should be marking the 
> transaction
> > for rollback, rather than actually rolling it back.
> 
> That is standard EJB behavior and what I would expect from the EJB  
> spec committee.

Agreed.

-Patrick
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Re: Exceptions thrown from callbacks

2007-02-01 Thread Dain Sundstrom

On Feb 1, 2007, at 3:27 PM, Patrick Linskey wrote:


3.5.6:

"Lifecycle callback methods may throw runtime exceptions. A runtime
exception thrown by a callback method that executes within a  
transaction
causes that transaction to be rolled back. No further lifecycle  
callback

methods will be invoked after a runtime exception is thrown."


One other thing to check is if the tx is marked rollback only, should  
we not call anymore lifecycle events or is that "NoFurther lifecycle  
callback" clause supposed to apply to the single entity that failed.



Further, I think that 3.7 trumps 3.5.6, so if an exception is thrown
from a callback during a find(), we should be marking the transaction
for rollback, rather than actually rolling it back.


That is standard EJB behavior and what I would expect from the EJB  
spec committee.


-dain