[wildfly-dev] Transactions in Batch (JSR 352)

[Jesper Pedersen]

On 02/04/2015 01:42 PM, James R. Perkins wrote:
> I'm retracting my email due to my misunderstanding. It's likely most
> item readers will not need a JTA data source. Therefore if you use a
> non-JTA data source you can cache the connection for the readItem()
> method. Any XA resources need to be opened and closed within the scope
> of a single transaction. For example ItemWriter.writeItems(List<Object>
> items) the XA resource must be opened and closed within this method and
> NOT in the ItemWriter.open() and ItemWriter.close() methods.
>
> In other words, there are no changes needed. It just needs to be noted
> one should not cache an XA data source in the open method and attempt to
> reuse it later.
>

Just remember that any non-transactional resources (NoTransaction) needs 
an explicit .close() in order to be returned to the connection pool. 
Otherwise you will out of connections fast ;) Scenarios like this can be 
investigated using the IronJacamar leak detector pool,

 
http://www.ironjacamar.org/doc/userguide/1.2/en-US/html/ch04.html#configuration_ironjacamar_leakpool

since there is no transactional boundary to do the check on.

Batch is still a bit up in the air IMHO, and the container is counting 
on the user to do the right thing. Which we all know doesn't always 
happen. So, I think it is a good idea to explore different transactional 
models looking at existing batch frameworks.

Best regards,
  Jesper