Implementing e-Transactions with Asynchronous Replication

An e-Transaction is one that executes exactly-once despite failures. This paper describes a distributed protocol that implements the abstraction of e-Transactions in three-tier architectures. Three-tier architectures are typically Internet-oriented architectures, where the end-user interacts with front-end clients (e.g., browsers) that invoke middle-tier application servers (e.g., web servers) to access back-end databases. We implement the e-Transaction abstraction using an asynchronous replication scheme that preserves the three-tier nature of the architecture and introduces a very acceptable overhead with respect to unreliable solutions.