A Context-Driven Commit Protocol for Enhancing Transactional Services Performance in Pervasive Environments

The proposed techniques for wireless environments during the last decade have limited support for dynamically changing environments. Due to its nature, the mobile computing environment is extremely dynamic and subject to rapid and unpredictable changes. Similarly, the characteristics of mobile applications affect their transactional requirements. The challenge is to reflect on solutions offering more flexibility and adaptability. In this article, the contribution was focused mainly on the problem of atomic commit that ensures the atomicity property. The trail of adapting mobile transaction commit protocols to context changes has been explored. This has led to the formalization of a flexible transaction model CATSM that supports adaptable properties and a commit protocol CA-TCP that enables adaptation to application requirements and mobile context in terms of transactional properties and execution cost. An architecture based on the concept of adaptation policy has also been designed for the implementation of the proposed solution.

Deco: A Decentralized, Cooperative Atomic Commit Protocol

An atomic commit protocol can cause long-term locking of databases if the coordinator crashes or becomes disconnected from the network. In this paper we describe how to eliminate the coordinator. This decentralized, cooperative atomic commit protocol piggybacks transaction statuses of all transaction participants onto tokens which are passed among the participants. Each participant uses the information in the tokens to make a decision of when to go to the next state of a three-phase commit protocol. Transactions can progress to ensure a uniform agreement on success or failure, even if the network is partitioned or nodes temporarily crash.

Reducing Blocking Risks of Atomic Transactions in MANETs Using a Backup Coordinator

In this paper, the authors present a probabilistic model to evaluate the reliability of the atomic commit for distributed transactions in mobile ad-hoc networks (MANETs). This model covers arbitrary MANET scenarios as well as strict and semantic transaction models. The authors evaluate the approach to integrate a backup coordinator to reduce blocking risks. For the purpose of showing an example of a MANET scenario, the authors illustrate how the considered blocking probability is very low.

Reducing Blocking Risks of Atomic Transactions in MANETs Using a Backup Coordinator

In this paper, the authors present a probabilistic model to evaluate the reliability of the atomic commit for distributed transactions in mobile ad-hoc networks (MANETs). This model covers arbitrary MANET scenarios as well as strict and semantic transaction models. The authors evaluate the approach to integrate a backup coordinator to reduce blocking risks. For the purpose of showing an example of a MANET scenario, the authors illustrate how the considered blocking probability is very low.