Research On Transaction Technology In Peer-to-Peer Data Management System

P2P(Peer-to-Peer) technology, one of the hotspots nowadays, has been widely used in Internet research areas and is considered very promising in applications like resource sharing, collaborative work, search engines, distributed computing and so on. Most of the problems about those applications come down to data location and data search, which promotes the combination of P2P technology and database technology and subsequently the generation of PDMS(Peer-to-Peer Data Management System). Compared to P2P network, PDMS has many advantages and is an ideal choice of infrastructure for connecting heterogeneous information sources.Transaction processing technology is one of the core elements of database and also a basic technique to ensure its consistency and efficiency. Transaction management in PDMS is different from that of previous distributed transactions, for it has no global transaction coordination mechanism. This thesis is mainly about the research on transaction processing technology in PDMS. Firstly, it comes up with a tree-shaped global transaction structure and a tree-shaped transaction execution controlling model. Secondly this thesis brings in the concept of equivalent child transaction and modifies the traditional committing principles of distributed transaction. Moreover, it proposes the transaction committing principles adapting to PDMS which are guided by the idea of committing transaction as soon as possible and defines a transaction committing protocol of PDMS. Thirdly, this thesis uses redundant distributed dependency graph to propose a concurrency controlling protocol which respects the autonomy and dynamic of PDMS. Finally, this thesis comes up with some failure recovering methods to solve the transaction failures in PDMS.This thesis investigates the transaction processing technologies in PDMS which are very meaningful to the future research on PDMS.