1. A machine-implemented configuration tool embodied on a machine-readable medium for configuring a cluster of application server instances comprising: a configuration file to define a cluster of application server instances, the cluster having an application server architecture comprising at least one application server instance, wherein each application server instance comprises a group of application servers configured with a redundant set of application logic and associated data, the cluster application server architecture further comprising a central database and a central services instance shared by the application server instances in the cluster, the central services instance having a locking service and a messaging service that enable communication and synchronization between each of the application server instances in the cluster; a data layer having the central database in which to store configuration information that defines the cluster of application server instances; a logic layer having one or more tasks, the one or more tasks to implement one or more functions of the configuration tool based on the configuration file; and a front-end layer to display the configuration information stored on the central database, and to provide a user interface for receiving input to generate the configuration file.