OSF DCE Administration Guide--Core Components

OSF DCE Administration Guide—Core Components

time-provider (the TP server), the TP server’s precise time is propagated throughout the

network. (See Section 23.2 for further information about time-providers and the server

synchronization process.)

23.1.3 Manageability

The DTS synchronization functions run as background processes; little or no input is

required from system managers to synchronize system clocks after DTS is initially

conﬁgured. DTS is also fault tolerant. It prevents malfunctioning clocks from providing

the wrong time to other clocks in the network. Occasionally, however, system managers

may need to perform the following functions:

• Identify system clock problems

• Adjust system clocks

• Change DTS attributes due to varying network conditions

• Modify system conﬁgurations when the network topology changes

DTS provides a full-featured management interface that allows system managers to

adjust system clocks, change the values of the DTS management parameters, and add or

subtract servers from the network.

To aid in solving problems with system clocks, DTS provides event reporting that

notiﬁes system operators and managers in the rare event that a system clock is inaccurate

or fails to synchronize.

23.1.4 Quantitative Inaccuracy Measurement

Unlike other network time services, DTS uses manufacturers’ speciﬁcations and direct

observation to determine the inaccuracy of system clocks relative to UTC. DTS appends

an inaccuracy measurement to each time value that it uses internally. This measurement

takes into account cumulative clock error, communications delays, and processing

delays. DTS uses combined time and inaccuracy measurements from one or several

sources to calculate the most accurate new clock settings for client systems. (See

Section 23.2.3 for further information about the DTS synchronization process.)

23.2 Basic DTS Concepts

The following subsections describe system clock and network characteristics, DTS

synchronization concepts, DTS clock adjustment, and DTS time representations. System

managers need to read these subsections to gain a basic understanding of DTS concepts

before progressing to Chapter 25.

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