Brian

What karaf version are you using?

Thanks

-D

On Wed, Sep 26, 2012 at 11:37 PM, Dan Tran <[email protected]> wrote:
> See my comments inline
>
> On Wed, Sep 26, 2012 at 10:05 PM, Brian Topping <[email protected]> wrote:
>> Dan, I went through a lot of this recently with OpenJPA.  YMMV with other 
>> providers.
>
> Brian, thank you for sharing this experience, it is surely settle our
> headache a bit!!
>
>>
>> 1. OpenJPA doesn't seem to manage very well with base classes across bundle 
>> boundaries.  It looked like there needed to be more magic in place that it 
>> could deal with not being able to enhance or otherwise modify the superclass 
>> jar due to classloader isolation.  I did set up build time enhancement but 
>> it didn't seem to be enough and I forgot where I was in the code that it was 
>> a problem.  One solution to this *may* be to use fragment hosts.  For now, 
>> we've just duplicated the base classes across the persistence bundles, 
>> kicking the can down the road a bit.
>>
>
> This would mean all your duplicate base classes have their own java
> package to prevent collision?
>
>> 2. I have been successful in having multiple persistence units in the same 
>> Karaf runtime and sharing a single data source, but the PUs do need to be 
>> named differently.  We have noticed some race conditions that occur, turning 
>> on JPA logging seems to bury them a little deeper, and we haven't had time 
>> to explore what's going on so we can report it.
>
> This is worry some. Are you able to bring your JPA into production
> with this issue?
>
>>
>> 3. One of the issues with multiple PUs is you need to set them up with 
>> different names for the sequence tables under DBs like Postgres and Oracle.  
>> This can be done statically from persistence.xml.
>>
>> I'm very interested in resolutions to these issues and would like to 
>> contribute to them, but have been under a lot of pressure with client 
>> deadlines.  I wonder if others have seen any of these issues yet and can 
>> offer any better advice than this.
>>
>> Cheers, B
>
> Thanks
>
> -D
>
>
>>
>> On Sep 26, 2012, at 9:01 PM, Dan Tran <[email protected]> wrote:
>>
>>> Hi,
>>>
>>> I am porting a set of JPA moduels under spring to Karaf JPA where I
>>> have i module which contains abstract entity classes, and a couple of
>>> other JPA modules use the 'base module', is it possible under
>>> jpa/openjpa/derby??
>>>
>>> I am struggling on what do do with the base module since it has no
>>> entities, what the persistent.xml looks like, should it has its own
>>> persistent unit?
>>>
>>> Can all three modules use the same persistent unit name?
>>>
>>> any suggestion is greatly appreciated.
>>>
>>> thanks
>>>
>>> -D
>>

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