An Agent Based Transaction Manager for Multidatabase Systems

A multidatabase system (MDBMS) is a facility that allows users to access data located in multiple autonomous database management systems (DBMSs) at different sites. To ensure global atomicity for multidatabase transactions, a reliable global atomic commitment protocol is a possible solution. In this protocol a centralized transaction manager (TM) receives global transactions, submits subtransactions to the appropriate sites via AGENTS. An AGENT is a component of MDBS that runs on each site; AGENTS after receiving subtransactions from the transaction manager perform the transaction and send the results back to TM. We have presented a unique proof-of-concept, a JAVA application for an Agent Based Transaction Manager that preserves global atomicity. It provides a user friendly interface through which reliable atomic commitment protocol for global transaction execution in multidatabase environment can be visualized. We demonstrated with three different test case scenarios how the protocol works. This is useful in further research in this area where atomicity of transactions can be verified for protocol correctness

Design and evaluation of a new transaction execution model for multidatabase systems

Cataloged from PDF version of article.In this paper, we present a new transaction execution model that captures the formalism and semantics of various extended transaction models and adopts them to a multidatabase system (MDBS) environment. The proposed model covers nested transactions, various dependency types among transactions, and commit independent transactions. The formulation of complex MDBS transaction types can be accomplished easily with the extended semantics captured in the model. A detailed performance model of an MDBS is employed in investigating the performance implications of the proposed transaction model. © Elsevier Science Inc. 1997

Location dependent transaction for mobile environment

With recent advances of mobile and portable devices, more than one billion cellular phones in the world joined by other wireless handheld computing devices like personal digital assistants (PDAs) or pocket PCs, with this number of users there are significant opportunities for mobile commerce growth. Although mobile commerce enables access to goods and service regardless of the location of either buyer or seller, in many situations the specific location of the buyer and seller is critical to the transaction [1]. Also the time for transaction execution become increasingly important not from performance point view but also from the corresponding relationship between the data and location especially when the mobile user change its location dynamically. In this paper we aim to introduce a mobile transaction model that takes into consideration the location dependent transaction and the time constraint for mobile transaction execution

Reliable scientific service compositions

Abstract. Distributed service oriented architectures (SOAs) are increas-ingly used by users, who are insufficiently skilled in the art of distributed system programming. A good example are computational scientists who build large-scale distributed systems using service-oriented Grid comput-ing infrastructures. Computational scientists use these infrastructure to build scientific applications, which are composed from basic Web ser-vices into larger orchestrations using workflow languages, such as the Business Process Execution Language. For these users reliability of the infrastructure is of significant importance and that has to be provided in the presence of hardware or operational failures. The primitives avail-able to achieve such reliability currently leave much to be desired by users who do not necessarily have a strong education in distributed sys-tem construction. We characterise scientific service compositions and the environment they operate in by introducing the notion of global scien-tific BPEL workflows. We outline the threats to the reliability of such workflows and discuss the limited support that available specifications and mechanisms provide to achieve reliability. Furthermore, we propose a line of research to address the identified issues by investigating auto-nomic mechanisms that assist computational scientists in building, exe-cuting and maintaining reliable workflows.

Mobile Transaction Supports for DBMS

National audienceIn recent years data management in mobile environments has generated a great interest. Several proposals concerning mobile transactions have been done. However, it is very difficult to have an overview of all these approaches. In this paper we analyze and compare several contributions on mobile transactions and introduce our ongoing research: the design and implementation of a Mobile Transaction Service. The focus of our study is on execution models, the manner ACID properties are provided and the way geographical movements of hosts (during transaction executions) is supported