OSF DCE Application Development Guide--Core Components

RPC and Other DCE Components
Before exporting, each server instance must acquire the entry name of its server
entry from an external source. When a unique server instance stops running, its
server entry becomes available. An available server entry should be reused for a
new instance of that server by providing the existing entry’s name for a new server
instance to use with the export operation. If any existing server entries are
unavailable, a new server instance requires a new server entry name.
For a discussion of when a server instance should remove the binding information
from its server entry, see the rpc_ns_binding_unexport(3rpc) reference page.
14.3.3.2 Using Groups
When a server is first installed on a system, the server or the installer creates one or
more server entries for the server. Also, when installing the first instance of the server
within a cell, the installer usually creates one or more groups for the application. For
any application, the local system and directory service administrators can create site-
specific groups whose members are server entries, groups, or both. Typically, a server
adds a server entry to at least one group.
Design decisions for defining groups may reflect a number of possible factors. Typical
factors that help define effective groups include the proximity of services or resources
to clients, the types of any resources offered by servers, the uses of UUIDs, and the
types of users that require a specific server.
For example, for a print server, proximity to the clients and the type of supported file
formats are both relevant. These factors may affect print servers as follows:
• Proximity
If the proximity of a server is important to clients, assign servers to groups
according to their locations. For example, print servers that are located together
can use their own group (for example, print servers in building 1 use the group
bldg_1_print_servers). Each server instance can add its own entry to the group,
or a system administrator can add server entries by using the RPC control
program.
To select randomly among servers in a given location, a client imports using the
name of a group that corresponds to those servers (or of a profile that refers to that
group).
Note: If proximity is the key factor in selecting among servers, name each
server entry for the server’s location; for example,
bldg_1_pole_27_print_server.
• Object types
When accessing specific classes of resources is important to clients, you can
group server instances based on the type of object they offer.
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