These synchronization settings are recommended to Clients by the Master and Slaves:
Note: This property page will only appear on the Master Server.
See Domain Role for more information on the Master, Slave, and Independent Server roles.
These settings will only take effect on clients if:
The Recommend timings and correction limits to clients that ask for guidelines checkbox is checked on the Master Server's Recommendations page.
The Accept server's recommended settings (if provided) checkbox is checked on the Client's Timings page.
Variable - check as often as needed to maintain approximately milliseconds sync with server
When this option is selected, Domain Time will automatically adjust how often it synchronizes with time sources to attempt to keep the clock within the threshold limit you set.
The wait period between time checks is called the window size. You can see the window size Domain Time is currently using by examining the Text Log.
Domain Time will adjust the window size based on how accurate previous time checks have been. If previous time corrections have been small the window size will be increased, and vice versa. The range of adjustment
for the window size is between 15 seconds to 2 hours. On most machines, it will average between 10 - 30 minutes.
The Variable scheduling method is intended for use on machines with relatively constant clock drift and moderate accuracy requirements (where the acceptable tolerance for clock drift is more than ~25ms).
This method strikes a good balance between maintaining the target accuracy while minimizing network traffic.
Variable is not a good selection if the machine is under heavy and/or variable load that causes the clock to drift by significant amounts on an irregular basis.
Since Domain Time may select a large window size if the clock on the machine has been well-behaved, anything that causes sudden clock drift during the Window period between checks can cause the clock to drift outside the specified threshold before the next correction.
If this describes your machine, you should use the Fixed schedule instead.
Fixed - check once every
If this option is selected, Domain Time will synchronize regularly on the schedule you specify.
This method is a good choice when you want to discipline the clock to stay within very tight synchronization tolerances. It's also the
best choice for machines with highly variable load, poor timekeeping hardware, or any other issue that causes significant clock drift.
You should check the time often enough to keep your Clients within your desired accuracy.
CAUTION: Take care with this setting. Many time servers have Denial-of-Service (DOS) protection to prevent abuse.
Issuing too many time requests in a row to one server over a short period of time can cause your machine to be locked out or even be permanently blacklisted.
This problem can be exacerbated if you have opted to collect multiple samples per time source. See About Time Samples.
If Domain Time cannot obtain the time, it should try again every:
sets how often Domain Time will retry its time sources if it is unable to successfully obtain the time. You will probably want to
check more often than during normal operation (unless you're already using a frequent synchronization schedule) to reacquire the correct time quickly when your time source(s) become available.
The same caution about synchronizing too often against your time sources (discussed above) applies.