From: Reza Rahman <reza_rahman@lycos.com>
To: Weld-Dev <weld-dev@lists.jboss.org>
Sent: Tue, November 24, 2009 8:47:32 PM
Subject: Re: [weld-dev] persistence and transactions outside Java EE
Emmanuel,
From what I understand, this is an
optimization that almost all sane
JTA providers have but it is not standards defined behavior. Also, I
think a sane JTA transaction manager could work with a non-XA resource
in optimized/local mode (again something I think could be defined at the
spec level but isn't).
I'm looking into some of these issues myself vis-a-vis Resin's
transaction manager and am thinking this could be a valuable blog topic
to help clear the air on some of this...
Cheers,
Reza
Emmanuel Bernard wrote:
> Transaction Managers do not engage in distributed transactions if
> there is a single resource and that happens automatically.
> JTA != 2PC.
> Jonathan, correct me if I'm wrong, but I'm sure that's something you
> guys have had in the product virtually for ever.
>
> On 24 nov. 09, at 18:18, Arbi Sookazian wrote:
>
>> This is a good idea from a corporate developer's
perspective
>> anyways. JEE platform needs to keep things as simple as possible
>> (esp. in terms of configuration) for the typical JEE dev.
>>
>> "Promotable transactions optimize distributed transactions by
>> deferring the creation of a distributed transaction until it is
>> needed. If only one resource manager is required, no distributed
>> transaction occurs."
>>
>> src:
http://msdn.microsoft.com/en-us/library/ms172070%28VS.80%29.aspx>>
>> Instead of focusing on how "apparently" bad the Spring stack is, I
>> would recommend focusing on expanding on the good ideas that .NET
>> platform has (like the late addition of MVC frmwk in ASP.NET
>> <
http://ASP.NET>!)
>>
>> Corporate devs are looking to design and code use cases
>> easily/quickly and not worry too much about system level issues,
>> clustering and lack of tooling, etc. An integrated solution like
>> .NET with the .NET Visual Studio IDE is very attractive (although
>> somewhat limiting perhaps b/c the APIs/frmwks are "locked" down).
>>
>> We have to make way too many decisions about what frmwks and
>> libraries to use in JEE (this problem seems to always be getting
>> worse as the years go by unfortunately).
>>
>> On Tue, Nov 24, 2009 at 9:03 AM, Reza Rahman <
reza_rahman@lycos.com >> <mailto:
reza_rahman@lycos.com>> wrote:
>>
>> Dan,
>>
>> Personally, I think the most elegant solution in terms of Java EE is
>> simply to standardize "promotable" transactions. Specifically,
>> JTA could
>> be modified to use local transactions by default and only promote
>> transactions to distributed mode as the need arises. The
>> Microsoft guys
>> have had promotable transactions for ages, I am not sure why we don't
>> have it in Java EE too. This would make the "lightweight" vs
>> "heavyweight" debate moot and keep things simple/consistent from a
>> developer's perspective while most of the systems-level issues
>> are
dealt
>> by the container where these things belong instead of a steady
>> leak as a
>> development concern.
>>
>> Cheers,
>> Reza
>>
>>
>> Dan Allen wrote:
>> > I was talking to someone about this topic post-Devoxx. I came
>> up with
>> > an idea that may be worth considering. Perhaps the Java EE platform
>> > can recognize another class of bean that has persistence and
>> > transaction capabilities, but not the rest of EJB. Here's my
>> proposed
>> > breakdown, in terms of airplane seat classes (I was on an
>> airplane at
>> > the time).
>>
>
>> > First class - EJB session bean
>> > Business class - local transactional bean
>> > Coach - Simple managed bean
>> >
>> > The main differientiator of a "business class bean" from an EJB is
>> > that it would have the option to use local transactions, just
>> like an
>> > application-managed JPA persistence unit. It would also not support
>> > any HA concerns. But it would be a drop in replacement for
>> so-called
>> > "lightweight" transaction beans that Spring offers.
>> >
>> > Then, we wouldn't need to do anything special in Weld / Seam 3.
>> All we
>> > would need is
to be able to support these types of beans in a
>> servlet
>> > container, the same way that Weld supports those environments.
>> But it
>> > would be a standard part of Java EE (6 MR1 or 7).
>> >
>> > If we feel like we need to support this use case in Seam, then
>> clearly
>> > there is still something missing in Java EE.
>> >
>> > -Dan
>> >
>> > On Wed, Nov 18, 2009 at 6:10 PM, Gavin King
>> <
gavin.king@gmail.com <mailto:
gavin.king@gmail.com>
>>
> <mailto:
gavin.king@gmail.com <mailto:
gavin.king@gmail.com>>> wrote:
>> >
>> > I think we should try and follow the Java EE models as
>> closely as
>> > possible for this stuff. We should simply try and make the
>> Java EE
>> > code work outside EE 6.
>> >
>> > e.g.
>> >
>> > (1) use a resource declaration with
>> @PersistenceContext(unitName=....)
>> > to define a managed persistence
context
>> > (2) use JBoss Transactions to manage transactions in a
>> servlet engine
>> > - so instead of having a special tx manager for JDBC, it is
>> just JTA
>> >
>> > Or is the 10meg download for JBoss Transactions just no good?
>> >
>> > --
>> > Gavin King
>> >
gavin.king@gmail.com <mailto:
gavin.king@gmail.com>
>> <mailto:
gavin.king@gmail.com
<mailto:
gavin.king@gmail.com>>
>> >
http://in.relation.to/Bloggers/Gavin>> >
http://hibernate.org>> >
http://seamframework.org>> > _______________________________________________
>> > weld-dev mailing list
>> >
weld-dev@lists.jboss.org <mailto:
weld-dev@lists.jboss.org>
>> <mailto:
weld-dev@lists.jboss.org <mailto:
weld-dev@lists.jboss.org>>
>> >
https://lists.jboss.org/mailman/listinfo/weld-dev>> >
>> >
>> >
>> >
>> > --
>> > Dan Allen
>> > Senior Software Engineer, Red Hat | Author of Seam in Action
>> > Registered Linux User #231597
>> >
>> >
http://mojavelinux.com>> >
http://mojavelinux.com/seaminaction>> >
http://www.google.com/profiles/dan.j.allen>> >
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