An integrated commit protocol for mobile network databases

Abstract

While traditional fixed-wired network protocols like 2-Phase-Commit guarantee atomicity, we cannot use them in mobile low bandwidth networks where network partitioning, node failure, and message loss may result in blocking. To deploy traditional database applications easily into a mobile environment, there is a demand for a protocol which guarantees an atomic commit of transactions. This paper introduces a protocol which can guarantee such atomic commitment in mobile environments using a combination of commit and consensus protocols. In addition, it takes advantage of mobile network sub-structures like single-hopenvironments to reduce message transfer costs.

A Failure Tolerating Atomic Commit Protocol for Mobile Environments

“…In contrast to our previous work [2], in which the idea of using a combination of 2PC [4], 3PC [14], and Paxos Consensus [9] was first described, our present paper theoretically examines the protocol blocking probability and shows important criteria for a good selection of multiple coordinators (i.e. usage of an odd number of coordinators; usage of multiple coordinators only if p < 0.5).…”

“…Beyond our previous paper [2], in this contribution we • prove protocol safety (correctness) and protocol liveness • compute the protocol blocking probability • experimentally determine its blocking probability • experimentally evaluate the protocol performance and justify practical protocol usability • give an important criterion for selecting an appropriate number of used coordinators. The rest of our paper is organized as follows: Section 2 describes the requirements to MCP, the underlying assumptions, and the system architecture.…”

“…Since a detailed description of the protocol can be found in [2], we only describe the main ideas of MCP and concentrate on the correctness proof and experimental evaluation.…”

Reducing Sub-transaction Aborts and Blocking Time Within Atomic Commit Protocols

“…For example, the extension of an atomic commit protocol by a non-blocking suspend state is not limited to 2PC, but appears to be compatible with a variety of other atomic commit protocols, e.g. [9], [10], or [11].…”

“…There are many contributions that handle coordinator failures, e.g., by running special termination protocols or by increasing coordinator availability with multiple coordinators (e.g [9], [10], or [11]). We only propose an improvement which is compatible to each of these commit protocols.…”