Hi, I also prefer to start with an examples of the transactional model described into OSGi JTA and JDBC spec. I hope that next week I will commit these small examples into samples. DataSource which automatically enlists connections into available transaction is not required by the spec but this feature is needed from other modules and I think that aries should provide it. One way to implement it is to stick to the j2ca but this is too heavy implementation from my point of view. I saw that a development of transactional DataSource was started in apache commons DBCP project. Probably it will be good to use it or to contribute to it if it is not ready.
Thanks, Nikolai. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Alasdair Nottingham Sent: Thursday, 14. January 2010 11:24 To: [email protected] Subject: Re: Transaction samples That is an interesting idea, but I think for now we should stick with using the OSGi JDBC spec approach. Alasdair 2010/1/13 David Jencks <[email protected]>: > > On Jan 13, 2010, at 7:05 AM, Timothy Ward wrote: > >> >> Hi Nikolai, >> >> I also agree that it would be great to include transactions in our >> samples. Obviously part of that involves enlisting XA resources with the >> transaction manager. I believe that the best way to do this is, as Alasdair >> says, to adapt the XADataSource into a vanilla DataSource, with some >> automatic logic to enlist the XAConnections in active transactions. > > I think that the way to do this is to use j2ca for connection pooling and > transaction enlistment and wrapping the XADatasource in a j2ca connector. > The geronimo connector framework is already available as bundles and the > tranql jdbc wrappers seem to work OK in an osgi environment. > > thanks > david jencks > >> >> JPA does make use of a JTA DataSource in managed environments, but the JPA >> provider expects to be provided with a DataSource that is automatically >> enlisted, not an XADataSource. This is another reason why the implementation >> Alasdair suggests would be useful. We could then re-use one implementation >> throughout Aries, rather than having a specific implementation for the JPA >> container. >> >> As far as I am aware there is no implementation that provides this >> behaviour in Aries, so it would definitely be welcome if you wanted to >> provide it. >> >> Regards, >> >> Tim >> >> >> >>> Date: Wed, 13 Jan 2010 14:25:35 +0000 >>> Subject: Re: Transaction samples >>> From: [email protected] >>> To: [email protected] >>> >>> Hi Nikolai, >>> >>> I agree we definitely need to have a sample showing how transactions >>> work. I had been thinking of updating the blog sample to include >>> transactions, but nothing immediate. If you want to go ahead and >>> either update the blog sample, or introduce a new one I think that >>> would be great. >>> >>> Since you mention the JDBC specification for derby I think it would be >>> good to have an implementation of this. It would be really nice if it >>> could adapt the XADataSource into a DataSource so the client would >>> just use the DataSource API, and would implicitly get the transaction >>> enlistment. I would do this separately from the sample and the derby >>> bundle you mention. >>> >>> I'm not sure I can answer your JPA question, but other will be able to. >>> >>> Thanks >>> Alasdair >>> >>> >>> 2010/1/13 Tankov, Nikolai <[email protected]>: >>>> >>>> Hi, >>>> >>>> I was checking the examples and saw that there are no examples which >>>> demonstrate how transactions (JTA Transaction Services Specification) and >>>> DB >>>> drivers (JDBC Service Specification) can be used. >>>> Do you plan to include transactional scenario in one of the existing >>>> examples? If no I can extend Derby bundle with an implement of interface >>>> org.osgi.service.jdbc.DataSourceFactory defined into OSGi enterprise spec. >>>> After that I can use it together with the existing transaction >>>> implementation in a simple example. >>>> What do you think about this idea? >>>> >>>> The implementation of JTA DataSource for JPA is also interesting. Are >>>> there any plans for an implementation? Or it is implemented but I did not >>>> found it :) >>>> >>>> Thanks! >>>> Nikolai. >>>> >>>> >>>> >>> >>> >>> >>> -- >>> Alasdair Nottingham >>> [email protected] >> >> >> _________________________________________________________________ >> Tell us your greatest, weirdest and funniest Hotmail stories >> http://clk.atdmt.com/UKM/go/195013117/direct/01/ > > -- Alasdair Nottingham [email protected]
