OSF DCE Administration Guide--Core Components

OSF DCE Administration Guide—Core Components
6. DNS looks up and returns to the GDA information that is associated with the
widget.com cell entry. The information includes the addresses of servers that
maintain replicas of the root directory of the /.../widget.com cell namespace.
7. The GDA passes the information about the foreign cell to the clerk.
8. The clerk contacts the CDS server on Node E in the foreign cell, passing it a
lookup request.
9. The Node E server’s clearinghouse contains a replica of the root directory, so the
server looks up the entry for printsrv1 in the root and passes the requested
information to the clerk on Node A. For simplicity, this example shows the clerk
contacting only one server in the foreign cell. While resolving a full name, the
clerk may actually receive referrals to several servers in the foreign cell.
10. The clerk passes the information to the client application that requested it.
Note that both of the previous examples (Figures 22-1 and 22-2) represent initial
lookups. The CDS clerk caches the locations of GDAs once it discovers them. The
clerk also caches the addresses of servers in foreign cells that it learns about, enabling it
to contact the foreign servers directly on subsequent requests for names in the same cell.
Note also that a GDA knows its own cell name and can therefore avoid contacting a
global directory service to look up names in its own cell. Furthermore, the GDA can
recognize whether a cell name conforms to the GDS or DNS naming syntax, and it uses
that knowledge to route a lookup request to the appropriate global directory service.
22.2 Managing the Global Directory Agent
Use the DCE configuration program to configure the GDA; the GDA requires little
management once it is configured. (See the for details on configuring the GDA.)
The GDA is typically started and stopped automatically by scripts that execute as part of
normal system startup and shutdown procedures. Sometimes, however, you may want to
use commands to stop and restart a GDA. Once you have configured GDA with the DCE
configuration program, you can use these steps to start and stop GDA.
The GDA runs as a process called gdad. To start the gdad process, follow these steps:
1. Make sure that a CDS server is already running somewhere within the cell.
2. Log into the system as superuser (root).
3. Enter the following command to see if the dced process is already running:
# ps
If the dced process appears on the list of active processes, proceed to step 5. If the
dced process does not appear on the list of active processes, enter the following
command to start the process:
# dced
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