A server group contains a template of an application server (and it's contents). It is based upon a server that you have set up and it is used for creating and managing copies of that server. The copies are called clones. The act of creating the clones is called cloning.
Cloning is an advanced technique for improving the performance and availability of an application server. Cloning allows the workload management system to transparently balance the application server workload among the clones in the server group and automatically switches users from failed application instances to active clones with no interruption in service. The transparency of cloning to the user makes cloning an invaluable technique for maintaining a highly efficient and reliable production environment.
The server group is a logical representation of the application server. It has the same structure and attributes as the real application server, but it is not associated with any nodes, and does not correspond to any real server process running on any node. In contrast, clones created from a server group represent real application server processes running on real nodes.
Clones are identical to the server group from which they are created, allowing identical application servers to be created. These copies can be used for workload management, since a request for a server resource can be handled by any of the server clones. Staring or stopping the server group will automatically start or stop the server clone. Changes to a server group will be propagated to its clones when the server group is restarted.
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