OSF DCE Administration Guide--Core Components

OSF DCE Administration Guide—Core Components

If a server is connected to a time-provider, set its checkinterval attribute. DTS uses the

checkinterval attribute to periodically check all the servers on a LAN to make sure that

they remain synchronized with the time-provider. When the amount of time speciﬁed by

the checkinterval attribute setting has elapsed, the server with the time-provider (the TP

server) performs the following procedure:

1. The TP server requests time values from all the other servers on the LAN.

2. The TP server starts the synchronization process.

3. The TP server identiﬁes the server time intervals that do not intersect with its own.

4. The TP server issues event messages for each faulty server it detects.

In the previous sequence, note that the TP server does not actually set the system clock

after it starts the synchronization process. The TP server merely runs the process to

detect faulty servers. The DTS software assumes that the time value at the TP server is

the most accurate available, so the TP server does not use the values it collects from

other servers to change its clock. Instead, the TP server functions as a reference

timekeeper for the other servers.

You can set the check interval to a lower value for a more rapid notiﬁcation of faulty

servers, but be aware that lower settings can increase the load on network resources.

The following example shows how to set the checkinterval attribute value:

dcecp> dts modify /.:/hosts -change {checkinterval 00-00:00:30.0000]

25.7 Changing the System Time

There are three ways you can change the system’s time by using dcecp commands. The

following subsections describe reasons for changing the system time, and then show

examples of the commands that you can use to modify the time and change the system

clock.

25.7.1 Updating the Time Monotonically

If your network does not use time-providers, and the network systems have been running

for some time, you may want to update the time on several systems to match UTC or

another external reference. When time-providers are absent from your network, the

systems remain closely synchronized, but their clocks may drift away from accepted

time standards such as UTC.

Use the dcecp clock set command when you want to modify the time on a server system

to make it more accurate. The DTS synchronization process ensures that the new time

you supply with the command is propagated to the other network systems. In order to

update the system clock to a new time, the new time and inaccuracy you specify for a

system must form a smaller interval than the current system interval.

25 − 20 Tandem Computers Incorporated 124243