OSF DCE Administration Guide--Introduction

OSF DCE Administration Guide—Introduction

When preparing for CDS, you need to select server nodes that store and maintain the

clearinghouses (CDS databases) in the cell. Keep the following guidelines in mind in

order to achieve reliability, optimum performance, and data availability:

• Choose dependable nodes. A CDS server wants to avoid downtime as much as

possible and needs to be restarted quickly when downtime occurs. The CDS server

needs to be one of the ﬁrst systems available on the network because client

applications and other DCE servers rely on the CDS server for up-to-date

information. The CDS server initializes the CDS namespace when you conﬁgure

DCE.

• Use reliable network connections. This helps to ensure that all servers maintaining

directory replicas can be reached when CDS performs a skulk. Skulks are periodic

updates that check for consistency across all replicas.

• Consider the size of your cell and how geographically dispersed the cell is when

deciding how many CDS servers you need. You should have at least two copies (one

master and one replica) of each CDS directory to ensure access to data if one of the

servers becomes unavailable.

• Each CDS server in a cell must maintain at least one clearinghouse. All

clearinghouses should contain a copy of the root, in addition to other directories

replicated there.

• Make replication decisions based on where the contents of directories are referenced.

Put replicas where the contents are read and put masters where the contents are

written.

In a DCE conﬁguration that uses GDS or DNS, CDS must be able to contact at least one

GDA to access global directory service. CDS contacts the GDA via the gdad daemon,

which sends lookup requests for cell names to either GDS or DNS and returns the results

to the CDS clerk in the cell that initiated the request.

The GDA can be on the same machine as a CDS server, or it can exist independently on

another machine. You should have at least two gdad daemons running in a cell to ensure

GDA availability.

3.2.6 DTSServer Programs

The DCE client conﬁguration already contains all the ﬁles necessary for a DTS server

machine, with the exception of the optional time provider. The necessary ﬁles are as

follows:

• The dtsd daemon, which is also installed on a DCE client machine, is conﬁgured to

run as a server when installed on a DTS server machine. As a server process, dtsd

synchronizes with other DTS servers, in addition to synchronizing the local clock, as

it does on a client machine.

• The dts_device_name_provider speciﬁes the communications between the DTS

server process and the time-provider process. For device_name, substitute the device

you are using, which can be a radio, clock, or modem, or another source of UTC time

for DTS. A time provider is optional. If you use a time provider, it must connect to a

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