WebSphere® ESB allows you to manage the deployment environment for your Service Component Architecture (SCA) modules as one collection of servers. WebSphere Application Server capabilities included with WebSphere ESB provide elements for this collection of servers.
The WebSphere ESB environment includes a layout of interconnected servers, or topology, which supports SCA modules of your service applications. This topology consists of one server process running on one computer system, or it can consist of multiple server processes running on multiple computer systems. A server process is a runtime environment for components that are deployed as SCA modules. In WebSphere products, including WebSphere ESB, a server process is a Java™ Virtual Machine (JVM).
If your environment consists of one server process on one system, the server process that is set up is called a stand-alone server. A stand-alone server does not have interconnections with other server processes, it has a capacity that is limited to the resources on that one computer system, and it does not include failover support. It is also the easiest environment to set up.
If your environment consists of multiple server processes, you most likely set up those processes as a clustered environment in a cell. A cell is a management domain of a distributed computing environment consisting of SCA modules and the resources needed to support them. A deployment environment is an environment in which server processes, typically on different physical computer systems, are managed together. One deployment manager can manage multiple deployment environments.
By nature, the z/OS® environment is clustered and can provide a highly scalable environment without all the complexities of separate clustered servers. Separate clustered servers can be used for multisystem nodes to provide additional availability.
For more information about establishing a deployment environment in WebSphere ESB, see "Implementing a deployment environment."