Adaptive commitment for distributed real-time transactions
Nandit R. Soparkar, Eliezer Levy, Henry F. Korth, Avi Silberschatz · 1994
Distributed real-time transaction systems are useful for both real-time and high-performance database applications. Standard transaction management approaches that use the two-phase commit protocol suffer from its high costs and blocking behavior which is problematic in real-time computing environments. Our approach in this paper is to identify ways in which a commit protocol can be made adaptive in the sense that under situations that demand it, such as a transient local overload, the system can dynamically change to a different commitment strategy. The decision to do so can be taken autonomously at any site. The different commitment strategies exploit a trade-off between the cost of commitment and the obtained degree of atomicity. Our protocols are based on optimistic commitment strategies, and they rely on local compensatory actions to recover from non-atomic executions. We provide the necessary framework to study the logical and temporal correctness criteria, and we describe examples to illustrate the use of our strategies.