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Interfaces

You use the Interfaces tab to define network interfaces, such as terminals and external raw interfaces, for the appliance. The appliance uses these terminals to interact with other appliances.

Terminals and External Raw Interfaces

The appliance terminals are named network interfaces, through which the appliance interacts with other appliances in the same application. The terminals have direction -- input or output . The terminal direction determines whether the appliance originates connections or accepts connections. You can also define external raw interfaces on this tab.

Each input terminal can have many appliances connected to it. Each output terminal can be connected only to a single appliance.

Name

Name of the terminal, representing the role of the interface within the appliance. It is a single word, case-sensitive, alphanumeric ([A-Za-z0-9_]). Terminal names are usually lowercase and short - 3 to 4 characters, so that they fit in the appliance terminal shape).

Type

Type of the connection: input, output, or raw. The direction determines whether the appliance originates connections (client-side of most protocols) or accepts connections (server-side of most protocols). The direction determines only where the connection originates from. The appliance can pass data in and out of any terminal.

Options

Optional terminal attributes that can be set on the terminal:
Mandatory Attribute Icon The mandatory attribute (denoted by an exclamation point) marks the terminal as required to connect for normal operation of the appliance. Typically inputs are non-mandatory and outputs are mandatory.
switch-sides button The switch-sides button makes the terminal appear on the other side of the appliance shape. It is useful for feedback terminals whose connection direction goes opposite to the general left-to-right flow. This attribute affects only the visual appearance, it has no runtime impact.
info button The info button shows information about the interior connection of the terminal -- if the terminal is already connected in the assembly interior, pressing this button may show you the protocol and other attributes of the terminal inside the assembly. If no information is shown, then the terminal is either not connected or there is an unresolved error.

The order of the terminals in the list, and in the appliance shape, can be modified by selecting a terminal entry in the list and using the up and down arrow buttons on the right side of the list. This is especially useful for appliances that have more than one terminal on one of the sides.

Important: If a terminal is marked as mandatory and then it is not connected, the application will not start. This helps ensure that configuration constraints are met and prevents many configuration errors from happening. CA AppLogic® will report the name of the appliance and the terminal that failed the check, so that you can easily locate and fix it.