Developing Enterprise Web Services: An Architect's Guide

Chapter 7. Transactions

Transactions are a fundamental abstraction in dependable computing systems. Put simply, a transaction is a unit of work which either succeeds completely or fails without leaving any side effects. To illustrate, a commonly cited example of a transaction use-case is where an amount of money is to be moved between bank accounts. In this case the goal is to ensure that the money both leaves the sender's account and is received by the recipient's account, or if something fails, for it to appear as if the transaction itself logically never occurred.

This is the inherent value of transactional systems; if something goes wrong, they allow us as programmers to make it appear as if it never happened in the first place. In an inherently ...