Paskirstytųjų objektinių duomenų bazių transakcijų valdymo protokolo tyrimas

• Main Author: Savickis, Donatas
• Other Authors: Mockus, Jonas
• Format: Dissertation
• Language: Lithuanian
• Published: Lithuanian Academic Libraries Network (LABT) 2005
• Subjects: Informatics; Consistency models; Piece-linear aggregates; Distributed systems; Vientisumo modeliai; Atkarpomis tiesiniai agregatai; GLOBDATA; Objektinės duomenų bazės; Paskirstytosios sistemos; Object-oriented databases
• Online Access: http://vddb.library.lt/fedora/get/LT-eLABa-0001:E.02~2005~D_20050530_002604-31076/DS.005.0.02.ETD

GLOBDATA is a project that aims to design and implement a middleware tool offering the abstraction of a global object database repository. This tool, called COPLA, supports transactional access to geographically distributed persistent objects independent of their location. Additionally, it supports replication of data according to different consistency criteria. For this purpose, COPLA implements a number of consistency protocols offering different tradeoffs between performance and fault-tolerance. This paper presents the analysis of one of two strong consistency protocols for the GLOBDATA system, the voting protocol. A protocol relies heavily on the use of atomic translation primitive as a building block to serialize conflicting transactions. The paper presents an in-depth description of the conceptual model using UML-based analysis of the protocol which later is used to define the PLA (piece-linear aggregates) model of the system, a discrete event-based simulation of the processes. As a result of the work, the PLA model is ready to be used to validate, verify and simulate various behavioral and performance characteristics of the model using mathematical proof techniques.