Neighborhood-Consistent Transaction Management for Pervasive Computing Environments

Abstract

Abstract. This paper examines the problem of transaction management in pervasive computing environments and presents a new approach to address them. We represent each entity as a mobile or static semi-autonomous device. The purpose of each device is to satisfy user queries based on its local data repository and interactions with other devices currently in its vicinity. Pervasive environments, unlike traditional mobile computing paradigm, do not differentiate between clients and servers that are located in a fixed, wired infrastructure. Consequently, we model all devices as peers. These environments also relax other assumptions made by mobile computing paradigm, such as the possibility of reconnection with a given device, support from wired infrastructure, or the presence of a global schema. These fundamental characteristics of pervasive computing environments limit the use of techniques developed for transactions in a "mobile" computing environments. We define an alternative optimistic transaction model whose main emphasis is to provide a high rate of successful transaction terminations and to maintain a neighborhood-based consistency. The model accomplishes this via the help of active witnesses and by employing an epidemic voting protocol. The advantage of our model is that it enables two or more peers to engage in a reliable and consistent transaction while in a pervasive environment without assuming that they can talk to each other via infrastructure such as base stations. The advantage of using active witnesses and an epidemic voting protocol is that transaction termination does not depend on any single point of a failure. Additionally, the use of an epidemic voting protocol does not require all involved entities to be simultaneously connected at any time and, therefore, further overcomes the dynamic nature of the environments. We present the implementation of the model and results from simulations.

SOUPA: Standard Ontology for Ubiquitous and Pervasive Applications

“…MoGATU is a framework for handling pro-active peerto-peer semantic data management in a pervasive computing environment [24,25]. The framework treats all devices present in the environment as equal semi-autonomous peers.…”

“…In Section 4, we discuss how SOUPA can be extended and used to support two different pervasive computing scenarios. One is in the context-aware smart meeting domain based on CoBrA [8], and the other is in the peerto-peer data management domain based on MoGATU [25]. Conclusions are given in Section 5.…”

SOUPA: standard ontology for ubiquitous and pervasive applications

“…In Section 4, we discuss how SOUPA can be extended and used to support two different pervasive computing scenarios. One is in the context-aware smart meeting domain based on CoBrA [8], and the other is in the peerto-peer data management domain based on MoGATU [25]. Conclusions are given in Section 5.…”