------------------------------------------------------------------------------- ** Note Room and Time ** ** Note Room and Time ** ------------------------------------------------------------------------------- B O S T O N U N I V E R S I T Y Computer Science Department P H D D E F E N S E Friday December 15, 1995 1:00pm * MCS 153 * ------------------------------------------------------------------------------- CLIENT-BASED LOGGING: A NEW PARADIGM FOR DISTRIBUTED TRANSACTION MANAGEMENT Euthimios Panagos The proliferation of inexpensive workstations and networks has created a new era in distributed computing. At the same time, non-traditional applications such as computer aided design (CAD), computer aided software engineering (CASE), geographic informa- tion systems (GIS), and office information systems (OIS) have placed increased demands for high-performance transaction pro- cessing on database systems. The combination of these factors gives rise to significant challenges in the design of modern da- tabase systems. % numerous performance opportunities In this thesis, we propose novel techniques whose aim is to improve the performance and scalability of these new database systems. These techniques exploit client resources through {\m client-based/} transaction management. Client-based transaction management is realized by providing logging facilities locally, even when data is shared in a global environment. This thesis presents several recovery algorithms which utilize client disks for storing recovery related informa- tion, i.e., log records. Our algorithms work with both coarse and fine granularity locking and they do not require the merging of client logs at any time. Moreover, our algorithms support fine granularity locking with multiple clients permitted to con- currently update different portions of the same database page. The database state is recovered correctly even if there is a com- plex crash, and if the updates performed by different clients on a page are not present on the disk version of the page, even though some of the updating transactions have committed. This thesis also presents the implementation of the proposed al- gorithms in a memory-mapped storage manager, as well as a de- tailed performance study of these algorithms using the OO1 data- base benchmark. The performance results show that client-based logging is superior to traditional server-based logging. This is because client-based logging is an effective way to reduce depen- dencies on server CPU and disk resources and, thus, prevents the server from becoming a performance bottleneck as quickly when the number of clients accessing the database increases. Advisor: Prof. Azer Bestavros ------------------------------------------------------------------------------- For colloquium info, including directions, see http://cs-www.bu.edu/colloquium For more information contact Prof. Mark Crovella -------------------------------------------------------------------------------