The xTrans Transaction Model and FlexCP Commit Protocol

Abstract

Traditionally, transactions are flat and atomic possessing the ACID properties. The traditional ACID transaction model has clear limitations in new application domains where transactions often are long-running and require properties that go beyond ACID. Structuring a long-running transaction as an ACID transaction will impede both performance and concurrency. To meet extended and varying transactional requirements, we have described a flexible transaction model, the xTrans model, providing support for both ACID and non-ACID properties. Further, current transaction processing systems in distributed environments are inflexible with respect to supporting extended transactions. Thus, to assist in the execution of, among others, xTrans transactions, we have designed a flexible commit protocol: FlexCP. This report presents the xTrans transaction model and the FlexCP commit protocol.