Performance Modeling of an Enhanced Optimistic Locking Architecture for Concurrency Control in a Distributed Database System
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Date
2005-12
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Research and Practice in Information Technology
Abstract
Optimistic methods of concurrency control are gaining popularity. This is especially true with the
resurgence of mobile and distributed databases during the last decade, which inherently rely on
optimistic techniques to improve availability and performance of the distributed database systems.
A key problem with optimistic techniques is that they do not perform well in highly conflict prone
environments. Pessimistic techniques, especially locking, perform much better under these
circumstances. In this research effort, the authors explored a hybrid technique called optimistic
locking architecture that provides locking for high conflict data items and optimistic access for the
rest. The model uses self-tuning that does not require the transaction manager, the transaction or
the user to incorporate any additional knowledge or to specify which data items or transactions
are optimistic. Rather, the system uses a data structure called lock buffer to maintain optimal level
of locks in the system. The empirical results obtained show that the performance of optimistic
concurrency control techniques can be significantly improved by using a relatively small lock
buffer. The analysis of the results also show improved performance degradation which is suitable
to the distributed database environment.
ACM Classification: C.2.4: Distributed Systems
Description
Journal of Research and Practice in Information Technology, Volume 37, No. 4,p.365-380.
Keywords
Datebased, self-tuning, Optimistic Locking, Architecture, Performance Modeling