We actually have parallel conversations going here. Putting aside the question of JTA overhead, the main concern is that JTA transactions simply aren't available in a servlet environment (without extra configuration). Hence my idea of having a lightweight transactional bean that makes use of local transactions rather than requiring JTA transactions provided by an EJB (or EJB lite) container.<br>
<br>Or perhaps, it's all unnecessary and we just tell people to use EJB lite if they want transactions and persistence.<br><br>-Dan<br><br><div class="gmail_quote">On Tue, Nov 24, 2009 at 2:49 PM, Reza Rahman <span dir="ltr"><<a href="mailto:reza_rahman@lycos.com">reza_rahman@lycos.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Gurkan,<br>
<br>
Thanks for that...reading through JTA/JCA has been on my wish-list for a<br>
while, I just haven't gotten around to it yet - the blog post exploring<br>
JTA performance would have been my final impetus :-).<br>
<br>
So the real overhead of JTA in optimized mode is what exactly (as far as<br>
you know)?<br>
<br>
Cheers,<br>
<font color="#888888">Reza<br>
</font><div><div></div><div class="h5"><br>
<br>
Gurkan Erdogdu wrote:<br>
> Hi;<br>
><br>
> Actually one-phase commit optimization is required for the Transaction<br>
> Managers.<br>
><br>
> See JCA 1.6 --> Section 7.6.3.3<br>
><br>
> --Gurkan<br>
><br>
> ------------------------------------------------------------------------<br>
> *From:* Reza Rahman <<a href="mailto:reza_rahman@lycos.com">reza_rahman@lycos.com</a>><br>
> *To:* Weld-Dev <<a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a>><br>
> *Sent:* Tue, November 24, 2009 8:47:32 PM<br>
> *Subject:* Re: [weld-dev] persistence and transactions outside Java EE<br>
><br>
> Emmanuel,<br>
><br>
> From what I understand, this is an optimization that almost all sane<br>
> JTA providers have but it is not standards defined behavior. Also, I<br>
> think a sane JTA transaction manager could work with a non-XA resource<br>
> in optimized/local mode (again something I think could be defined at the<br>
> spec level but isn't).<br>
><br>
> I'm looking into some of these issues myself vis-a-vis Resin's<br>
> transaction manager and am thinking this could be a valuable blog topic<br>
> to help clear the air on some of this...<br>
><br>
> Cheers,<br>
> Reza<br>
><br>
><br>
> Emmanuel Bernard wrote:<br>
> > Transaction Managers do not engage in distributed transactions if<br>
> > there is a single resource and that happens automatically.<br>
> > JTA != 2PC.<br>
> > Jonathan, correct me if I'm wrong, but I'm sure that's something you<br>
> > guys have had in the product virtually for ever.<br>
> ><br>
> > On 24 nov. 09, at 18:18, Arbi Sookazian wrote:<br>
> ><br>
> >> This is a good idea from a corporate developer's perspective<br>
> >> anyways. JEE platform needs to keep things as simple as possible<br>
> >> (esp. in terms of configuration) for the typical JEE dev.<br>
> >><br>
> >> "Promotable transactions optimize distributed transactions by<br>
> >> deferring the creation of a distributed transaction until it is<br>
> >> needed. If only one resource manager is required, no distributed<br>
> >> transaction occurs."<br>
> >><br>
> >> src: <a href="http://msdn.microsoft.com/en-us/library/ms172070%28VS.80%29.aspx" target="_blank">http://msdn.microsoft.com/en-us/library/ms172070%28VS.80%29.aspx</a><br>
> >><br>
> >> Instead of focusing on how "apparently" bad the Spring stack is, I<br>
> >> would recommend focusing on expanding on the good ideas that .NET<br>
> >> platform has (like the late addition of MVC frmwk in <a href="http://ASP.NET" target="_blank">ASP.NET</a><br>
> >> <<a href="http://ASP.NET" target="_blank">http://ASP.NET</a>>!)<br>
> >><br>
> >> Corporate devs are looking to design and code use cases<br>
> >> easily/quickly and not worry too much about system level issues,<br>
> >> clustering and lack of tooling, etc. An integrated solution like<br>
> >> .NET with the .NET Visual Studio IDE is very attractive (although<br>
> >> somewhat limiting perhaps b/c the APIs/frmwks are "locked" down).<br>
> >><br>
> >> We have to make way too many decisions about what frmwks and<br>
> >> libraries to use in JEE (this problem seems to always be getting<br>
> >> worse as the years go by unfortunately).<br>
> >><br>
> >> On Tue, Nov 24, 2009 at 9:03 AM, Reza Rahman <<a href="mailto:reza_rahman@lycos.com">reza_rahman@lycos.com</a><br>
> <mailto:<a href="mailto:reza_rahman@lycos.com">reza_rahman@lycos.com</a>><br>
</div></div><div><div></div><div class="h5">> >> <mailto:<a href="mailto:reza_rahman@lycos.com">reza_rahman@lycos.com</a> <mailto:<a href="mailto:reza_rahman@lycos.com">reza_rahman@lycos.com</a>>>> wrote:<br>
> >><br>
> >> Dan,<br>
> >><br>
> >> Personally, I think the most elegant solution in terms of Java EE is<br>
> >> simply to standardize "promotable" transactions. Specifically,<br>
> >> JTA could<br>
> >> be modified to use local transactions by default and only promote<br>
> >> transactions to distributed mode as the need arises. The<br>
> >> Microsoft guys<br>
> >> have had promotable transactions for ages, I am not sure why we<br>
> don't<br>
> >> have it in Java EE too. This would make the "lightweight" vs<br>
> >> "heavyweight" debate moot and keep things simple/consistent from a<br>
> >> developer's perspective while most of the systems-level issues<br>
> >> are dealt<br>
> >> by the container where these things belong instead of a steady<br>
> >> leak as a<br>
> >> development concern.<br>
> >><br>
> >> Cheers,<br>
> >> Reza<br>
> >><br>
> >><br>
> >> Dan Allen wrote:<br>
> >> > I was talking to someone about this topic post-Devoxx. I came<br>
> >> up with<br>
> >> > an idea that may be worth considering. Perhaps the Java EE<br>
> platform<br>
> >> > can recognize another class of bean that has persistence and<br>
> >> > transaction capabilities, but not the rest of EJB. Here's my<br>
> >> proposed<br>
> >> > breakdown, in terms of airplane seat classes (I was on an<br>
> >> airplane at<br>
> >> > the time).<br>
> >> ><br>
> >> > First class - EJB session bean<br>
> >> > Business class - local transactional bean<br>
> >> > Coach - Simple managed bean<br>
> >> ><br>
> >> > The main differientiator of a "business class bean" from an EJB is<br>
> >> > that it would have the option to use local transactions, just<br>
> >> like an<br>
> >> > application-managed JPA persistence unit. It would also not<br>
> support<br>
> >> > any HA concerns. But it would be a drop in replacement for<br>
> >> so-called<br>
> >> > "lightweight" transaction beans that Spring offers.<br>
> >> ><br>
> >> > Then, we wouldn't need to do anything special in Weld / Seam 3.<br>
> >> All we<br>
> >> > would need is to be able to support these types of beans in a<br>
> >> servlet<br>
> >> > container, the same way that Weld supports those environments.<br>
> >> But it<br>
> >> > would be a standard part of Java EE (6 MR1 or 7).<br>
> >> ><br>
> >> > If we feel like we need to support this use case in Seam, then<br>
> >> clearly<br>
> >> > there is still something missing in Java EE.<br>
> >> ><br>
> >> > -Dan<br>
> >> ><br>
> >> > On Wed, Nov 18, 2009 at 6:10 PM, Gavin King<br>
> >> <<a href="mailto:gavin.king@gmail.com">gavin.king@gmail.com</a> <mailto:<a href="mailto:gavin.king@gmail.com">gavin.king@gmail.com</a>><br>
> <mailto:<a href="mailto:gavin.king@gmail.com">gavin.king@gmail.com</a> <mailto:<a href="mailto:gavin.king@gmail.com">gavin.king@gmail.com</a>>><br>
> >> > <mailto:<a href="mailto:gavin.king@gmail.com">gavin.king@gmail.com</a> <mailto:<a href="mailto:gavin.king@gmail.com">gavin.king@gmail.com</a>><br>
> <mailto:<a href="mailto:gavin.king@gmail.com">gavin.king@gmail.com</a> <mailto:<a href="mailto:gavin.king@gmail.com">gavin.king@gmail.com</a>>>>> wrote:<br>
> >> ><br>
> >> > I think we should try and follow the Java EE models as<br>
> >> closely as<br>
> >> > possible for this stuff. We should simply try and make the<br>
> >> Java EE<br>
> >> > code work outside EE 6.<br>
> >> ><br>
> >> > e.g.<br>
> >> ><br>
> >> > (1) use a resource declaration with<br>
> >> @PersistenceContext(unitName=....)<br>
> >> > to define a managed persistence context<br>
> >> > (2) use JBoss Transactions to manage transactions in a<br>
> >> servlet engine<br>
> >> > - so instead of having a special tx manager for JDBC, it is<br>
> >> just JTA<br>
> >> ><br>
> >> > Or is the 10meg download for JBoss Transactions just no good?<br>
> >> ><br>
> >> > --<br>
> >> > Gavin King<br>
> >> > <a href="mailto:gavin.king@gmail.com">gavin.king@gmail.com</a> <mailto:<a href="mailto:gavin.king@gmail.com">gavin.king@gmail.com</a>><br>
> <mailto:<a href="mailto:gavin.king@gmail.com">gavin.king@gmail.com</a> <mailto:<a href="mailto:gavin.king@gmail.com">gavin.king@gmail.com</a>>><br>
> >> <mailto:<a href="mailto:gavin.king@gmail.com">gavin.king@gmail.com</a> <mailto:<a href="mailto:gavin.king@gmail.com">gavin.king@gmail.com</a>><br>
</div></div><div><div></div><div class="h5">> <mailto:<a href="mailto:gavin.king@gmail.com">gavin.king@gmail.com</a> <mailto:<a href="mailto:gavin.king@gmail.com">gavin.king@gmail.com</a>>>><br>
> >> > <a href="http://in.relation.to/Bloggers/Gavin" target="_blank">http://in.relation.to/Bloggers/Gavin</a><br>
> >> > <a href="http://hibernate.org" target="_blank">http://hibernate.org</a><br>
> >> > <a href="http://seamframework.org" target="_blank">http://seamframework.org</a><br>
> >> > _______________________________________________<br>
> >> > weld-dev mailing list<br>
> >> > <a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a> <mailto:<a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a>><br>
> <mailto:<a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a> <mailto:<a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a>>><br>
> >> <mailto:<a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a><br>
> <mailto:<a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a>> <mailto:<a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a><br>
> <mailto:<a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a>>>><br>
> >> > <a href="https://lists.jboss.org/mailman/listinfo/weld-dev" target="_blank">https://lists.jboss.org/mailman/listinfo/weld-dev</a><br>
> >> ><br>
> >> ><br>
> >> ><br>
> >> ><br>
> >> > --<br>
> >> > Dan Allen<br>
> >> > Senior Software Engineer, Red Hat | Author of Seam in Action<br>
> >> > Registered Linux User #231597<br>
> >> ><br>
> >> > <a href="http://mojavelinux.com" target="_blank">http://mojavelinux.com</a><br>
> >> > <a href="http://mojavelinux.com/seaminaction" target="_blank">http://mojavelinux.com/seaminaction</a><br>
> >> > <a href="http://www.google.com/profiles/dan.j.allen" target="_blank">http://www.google.com/profiles/dan.j.allen</a><br>
> >> ><br>
> >><br>
> ------------------------------------------------------------------------<br>
> >> ><br>
> >> > _______________________________________________<br>
> >> > weld-dev mailing list<br>
> >> > <a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a> <mailto:<a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a>><br>
> <mailto:<a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a> <mailto:<a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a>>><br>
> >> > <a href="https://lists.jboss.org/mailman/listinfo/weld-dev" target="_blank">https://lists.jboss.org/mailman/listinfo/weld-dev</a><br>
> >><br>
> >> _______________________________________________<br>
> >> weld-dev mailing list<br>
> >> <a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a> <mailto:<a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a>><br>
> <mailto:<a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a> <mailto:<a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a>>><br>
> >> <a href="https://lists.jboss.org/mailman/listinfo/weld-dev" target="_blank">https://lists.jboss.org/mailman/listinfo/weld-dev</a><br>
> >><br>
> >><br>
> >> _______________________________________________<br>
> >> weld-dev mailing list<br>
> >> <a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a> <mailto:<a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a>><br>
> <mailto:<a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a> <mailto:<a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a>>><br>
> >> <a href="https://lists.jboss.org/mailman/listinfo/weld-dev" target="_blank">https://lists.jboss.org/mailman/listinfo/weld-dev</a><br>
> ><br>
</div></div>> > ------------------------------------------------------------------------<br>
<div><div></div><div class="h5">> ><br>
> > _______________________________________________<br>
> > weld-dev mailing list<br>
> > <a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a> <mailto:<a href="mailto:weld-dev@lists.jboss.org">weld-dev@lists.jboss.org</a>><br>
> > <a href="https://lists.jboss.org/mailman/listinfo/weld-dev" target="_blank">https://lists.jboss.org/mailman/listinfo/weld-dev</a><br>
><br>
> _______________________________________________<br>
> weld-dev mailing list<br>
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> <a href="https://lists.jboss.org/mailman/listinfo/weld-dev" target="_blank">https://lists.jboss.org/mailman/listinfo/weld-dev</a><br>
><br>
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</div></div></blockquote></div><br><br clear="all"><br>-- <br>Dan Allen<br>Senior Software Engineer, Red Hat | Author of Seam in Action<br>Registered Linux User #231597<br><br><a href="http://mojavelinux.com">http://mojavelinux.com</a><br>
<a href="http://mojavelinux.com/seaminaction">http://mojavelinux.com/seaminaction</a><br><a href="http://www.google.com/profiles/dan.j.allen">http://www.google.com/profiles/dan.j.allen</a><br>