4.1 Introduction Unidirectional replication using Q replication may be the replication of choice for environments that require a high-volume, low-latency solution between one or more tables on two servers, with the ability to perform transformations on the target tables. Such scenarios are typical of: Data warehousing applications that require simple to complex data transformations of operational data. Offloading of query reporting away from critical operational systems, by creating complete or partial subsets of operational data with or without transformations. In this chapter we describe an existing WebSphere MQ shared queues high availability business solution implementation, into which is seamlessly introduced a unidirectional Q replication application. This unidirectional Q replication application coexists synergistically with the WebSphere MQ shared queues high availability solution. A brief overview of the business requirement is followed by a description of the environment configuration. The setup of this WebSphere MQ shared queues HA environment with unidirectional replication is described, followed by test cases showing the successful operation of the application in this environment. The topics covered in the following sections are: Business requirement Rationale for the unidirectional solution Environment configuration Set up of this environment Test cases