Advanced Prototypes

Bourgogne Transactions Prototype

Author: Distributed Systems Research Group, Charles University.

Contact: Marek Prochazka.

The prototype implements Bourgogne Transactions in JOnAS 2.3. Bourgogne Transactions provide support for long-lived transactional computations and cooperation among transactions. In Bourgogne Transactions, a wide range of advanced transaction models can be employed thanks to newly introduced advanced transaction primitives that cover establishing flow control dependencies among transactions, sharing beans among transactions, and delegation of beans from one transaction to another.

Enhanced EJB Component Architecture Model

Author: Distributed Systems Research Group, Charles University.

Contact: Radek Pospisil.

Enhanced EJB component architecture model is a proposal for enhancing and of current EJB component architecture model. The main goals are: multiple interfaces for components, provides/requires specification of components, hierarchical component architecture and configurable component behavior. In this model, components can be constructed with better reusability, can provide functionality with finer granularity and improve cooperation between components. Services such as transactions, persistence and security are not considered nor enhanced in this proposal.

Extension to the Close Nested Transaction model

Author: LAMIH/ROI/SID, University of Valenciennes.

Contact: Sergiy Nemchenko.

Currently, the Enterprise JavaBean supports only the flat transactions model. However, this model is not suitable with long-lived transactions: a transaction failure implies to discard all changes performed in the transaction scope. With Close Nested Transaction (CNT) model, we split the flat transaction into sub transactions to allow performing actions with more parallelism. Moreover, a failure will discard actions done in the sub transaction and a new sub transaction offering an alternative service can be launched. In the scope of Pepita, first, we have extended the set of supported transactions model by the JTM to the CNT model by adding two transactional attributes in Jonas 2.4. This implies to add the CNT behaviour to the EJB container according to our new attribute proposal and the transaction manager according to OTS specifications.

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Extension to the Open Nested Transaction Model

Author: LAMIH/ROI/SID, University of Valenciennes.

Contact: Sergiy Nemchenko.

Open Nested Transactions relax the isolation property by making the results of committed sub-transactions visible to other concurrently executed transactions. This feature improves degree of concurrency. The need of compensation in the case of ancestor's rollback is the main disadvantage. We propose extension of EJB's TM to the ONT model.

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