Juergen discusses transactions as key to enterprise applications, the different types of transactions, the supposed universality of XA transactions and the alternative of using native transactions using the Spring framework. He talks about native transaction support by modern application frameworks and shares scenarios of Spring Framework users to illustrate the power of native transactions.
Juergen Hoeller co-founder of Spring Framework, sees 3.0 as the completion of what was started with 2.5. Some topics covered in his presentation are: more annotation-based configuration options, Unified EL++, REST, Portlet 2.0 and Java EE6 support.
SpringOne is the annual conference for the global Spring community held in both Europe and the Americas. SpringOne Europe 2009 focused on the emerging technologies and best practices around the Spring Framework and enterprise software development. The event featured the project founders, core committers, authors, consultants, project leads, and professional trainers.
Re: Bad presenter
No jokes, no funny pictures, no funny stories
want edutainment?: try martin fowler. although not without substance, you won't find there the combination of breadth and depth of knowledge displayed here... and if you find a funny story about transaction management please do pass it on ;-)
From my simple world view you can break distributed transactions into 2 cases.
1. You want 2 phase commit across multiple DBMS/JMS Queues
2. You want transaction semantics across network calls (EJB 1 & 2 etc)
The way I see it Juergen did a pretty good job of talking about the first case - aka 2pc over multiple resource managers has a significant cost and other alternative approaches exist.
EJB 1 and 2 is a good example of the other case imo. That is, it tried to make the network transparent (remote EJB calls) and pretty much needed a transaction manager to ensure those remote calls could all together be treated atomically (~ Corba anyone?).
In my book the common alternative to EJB 1/2 remote calls approach is to use web services. Generally each web service call executes atomically by itself - aka you generally don't have a 'transaction' spanning multiple web service calls (you might use state transitions of the underlying data instead).
That's my high level view of your question anyway. I end up converting your questions to...
- When is 2PC over multiple Resource Managers (DBMS/JMS) justified?
- When making RPC type calls when is EJB justified over say individually atomic web services.
Hopefully that is an interesting/useful perspective.
What is he saying with "There is a very small percentage of systems that need remote transactions"? Is it true? Is the distributed transactions market over sold?
You bet. It's always been. Most distributed systems are pretty much e-commerce sites or internal transaction processing systems, and in most of them (at least the ones I've seen), pretty much do local transactions.
Unfortunately, many of these systems set their connection pools to be XA connection pools, but they still end up using only one database, or if using multiple databases, their business rules get them to do transactions in each separately. It is very rare that you really have to set up a transaction to be committed as all-or-nothing simultaneously on more than one resource.
Blame it to software vendors and academia for forcing a theoretical white elephant that's only good for a narrow problem domain to the general IT populace :)
Vendors do tend to skip out the "... you don't want to use this feature in this scenario because...". IMO this is why presentations like this are important.
For me part of the 'problem' was that JTA it was a requirement of EJB v1 due to its remoting/distributed nature... so by default people would tend to use XA/2PC for their DB transactions. So 2PC wasn't always *sold* but came with the J2EE territory. I'm not sure how many developers/engineers thought critically of the implications but instead went with the flow.