Hi Michael and Pinaki,
Yes, I understood how this is supposed to work, however this does not and
can not work for us this way out-of-the box.
I think I forgot to emphasize, that we are not an ORM and are not using
JDBC connections.
Of course we can (and would) register a Synchronization object with the
global transaction.
But where should the container get the XAResource from? Because we are not
using JDBC connections, which implies, we
are not using any DataSource. So there is simply no way for the app server
to drive the XA protocol.
Unless of course, we would provide a "fake" XADataSource in a "fake" JDBC
driver, and given the pseudo-code assumption
from my previous mail, we would then just call "getConnection()" on the
jta-data-source (which points to an app server pool
configured with our "fake" JDBC driver, configured to return enlisted
connections) and don't actually use the result
of the "getConnection()" invocation (which is a dummy implementation
anyways)
I'm pretty sure, that my pseudo-code assumption is correct, mostly because
I can not think of any other straight-forward
(or even weird) way how to implement that in the app server.
So this would be the way to go for us.
Regards,
Christian
On Fri, May 11, 2012 at 10:45 PM, michael keith <michael.keith_at_oracle.com>wrote:
> Hi Christian,
>
> Yes, that's pretty much how it works.
>
> -Mike
>
>
> On 11/05/2012 9:45 AM, Christian Romberg wrote:
>
> Hi Mike,
>
> Unlike ORMs, we need to provide the XAResource instances to the app server
> (which in turn are associated with our internal connections to the
> database server)
>
> But I guess, if the user just sees a DataSource, then that will be an app
> server proxy which eventually delegates to the XADataSource of
> our "JDBC" driver (provided I configure a DataSource that returns enlisted
> connection in the app server using our JDBC driver)
>
> So my pseudo-code assumption of the app servers DataSource proxy is like
> this:
>
> public class ContainerDataSourceProxy implements DataSource {
>
> XADataSource xaDs = ...; //XADataSource of the installed JDBC driver
> for this pool
>
> public Connection getConnection() throws SQLException {
> XAConnection xaCon = xaDs.getXAConnection();
> enlist(xaCon.getXAResource());
> return xaCon.getConnection();
> }
> ...
> }
>
> So we could simply call getConnection() (and not using the returned value
> at all) to trigger the app servers
> enlisting our XAResource.
>
> Regards,
>
> Christian
>
> On Fri, May 11, 2012 at 3:14 PM, michael keith <michael.keith_at_oracle.com>wrote:
>
>> Hi Christian,
>>
>> The data source referenced by the jta-data-source name is a DataSource
>> provided by the container in JNDI. It is the same one that any application
>> could look up and use, hence it is a javax.sql.DataSource.
>>
>> XADataSource is an internal type used by the driver and container to
>> coordinate XA, but users of the data source are not expected to participate
>> at that level. The JPA provider acts like a client of the data source,
>> using its connections to read and write, so it does not need to be aware of
>> the XA protocol being implemented underneath.
>>
>> Hope this makes things clearer.
>>
>> Regards,
>> -Mike
>>
>>
>> On 10/05/2012 7:50 AM, Christian Romberg wrote:
>>
>> Hello,
>>
>> It is not explicitly mentioned in the spec, but I guess I can safely
>> assume, that the data source denoted by
>> jta-data-source is of type "javax.sql.XADataSource"?
>>
>> After the JPA implementation has obtained an XAConnection from this
>> XADataSource, is it expected to
>> to do any calls (and if so, in any specific order) on this XAConnection?
>>
>> E.g. is it necessary, to call XAConnection.getConnection() to trigger
>> that the app server calls XAConnection.getXAResource()
>> on the very same XAConnection? Or is it sufficient to just call
>> "XADataSource.getXAConnection()" to trigger this?
>>
>> (Some background: we don't use JDBC connections (being not an ORM) and
>> probably we would need to provide our own
>> XADataSource implementation, so that the app server picks up our own
>> XAResource implementation)
>>
>> Thank you!
>>
>> Christian
>>
>> --
>> Christian Romberg
>> Chief Engineer | Versant GmbH
>> (T) +49 40 60990-0
>> (F) +49 40 60990-113 <%2B49%2040%2060990-113>
>> (E) cromberg_at_versant.com
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>
>
> --
> Christian Romberg
> Chief Engineer | Versant GmbH
> (T) +49 40 60990-0
> (F) +49 40 60990-113
> (E) cromberg_at_versant.com
> www.versant.com<http://www.google.com/url?q=http%3A%2F%2Fwww.versant.com%2F&sa=D&sntz=1&usg=AFrqEzeeEBc_gN_8mxtt8xDB0tjXDXQVlw>|
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>
> --
> Versant
> GmbH is incorporated in Germany. Company registration number: HRB
> 54723, Amtsgericht Hamburg. Registered Office: Halenreie 42, 22359
> Hamburg, Germany. Geschäftsführer: Bernhard Wöbker, Volker John
>
> CONFIDENTIALITY
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--
Christian Romberg
Chief Engineer | Versant GmbH
(T) +49 40 60990-0
(F) +49 40 60990-113
(E) cromberg_at_versant.com
www.versant.com<http://www.google.com/url?q=http%3A%2F%2Fwww.versant.com%2F&sa=D&sntz=1&usg=AFrqEzeeEBc_gN_8mxtt8xDB0tjXDXQVlw>|
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--
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GmbH is incorporated in Germany. Company registration number: HRB
54723, Amtsgericht Hamburg. Registered Office: Halenreie 42, 22359
Hamburg, Germany. Geschäftsführer: Bernhard Wöbker, Volker John
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NOTICE: This e-mail message, including any attachments, is for the sole
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