Server core refers to the core binaries required for the Web Server environment. If Server Core is selected, an Administration instance is created and it can be configured as either the Administration Server or the Administration Node, both of which are described below. If the Administration instance is configured as Administration Server, a default Web Server instance is installed. These installation options are used in server farm environments in which a centralized Administration Server resides on one of the nodes and Administration Nodes reside on the rest.
The Administration Server is a specially configured Web Server instance used only for administration purposes and on which administration applications are deployed. Each node in a server farm or cluster environment has an Administration Server running on it. Of these nodes, one is configured to be the master server, referred to as the Administration Server, and the rest are configured to be slave servers, referred to as Administration Nodes (described below). The Administration Server is used to administer all Web Server instances in a server farm and to push configurations to the various nodes. The master Administration Server runs the graphical administration console and command-line administration interface, while the nodes in the farm run just the Administration Node application. The Administration Server maintains the configuration repository for all instances.
The Administration Node is a Web Server instance without the features and functionality of the Administration Server (no graphical console, for instance). The Administration Node receives commands from the designated Administration Server and performs limited actions on that particular node, such as creating, deleting, starting, and stopping Web Server instances. Instances can be created on Administration Nodes only by the Administration Server. The nodes within a server farm or cluster cannot be configured independently.
The Administration Node must be registered with the Administration Server, either during the installation (see the related steps in Chapter 2, Installing the Web Server) or after installation (see Registering the Administration Node From the Command-Line). The Administration Server must be running during the registration.
When considering the options described above, use the following general guidelines:
If you are not setting up a server farm and want just a straightforward Web Server, choose to configure the Administration instance as the Administration Server. A default Web Server instance will also be created.
If you are setting up a server farm, first configure the centralized Administration Server instance. Then configure the rest of the nodes in the server farm as Administration Nodes by selecting the option to configure the Administration instance as an Administration Node. If you configure the Administration instance as the Administration Server, a default Web Server instance is also created.