Domain Time Sync Test
NTP is a fault-tolerant, highly scalable time protocol and it is used for synchronizing computer clocks by using a designated reference clock. A reference clock is some device or machinery that spits out the current time. The special thing about these things is accuracy. Reference clocks must be accurately following some time standard. NTP will compute some additional statistical values based on the current time reported by the reference clock, which will describe the quality of time it sees. Among these values are: offset (or phase), jitter (or dispersion), frequency error, and stability. Thus each NTP server will maintain an estimate of the quality of its reference clocks and of itself.
This test reports the time difference between the reference clock and that of the target environment, and thus helps assess the quality of time seen by the windows server. With the help of this test, you can also easily determine whether the reference time changed recently.
Target of the test : A Windows/Unix host
Agent deploying the test : An internal agent
Outputs of the test : One set of results for the host being monitored
|
Measurement | Description | Measurement Unit | Interpretation |
---|---|---|---|
NTP offset: |
Indicates the time difference between the local clock and the designated reference clock. |
Secs |
For a tiny offset, NTP will adjust the local clock; for small and larger offsets, NTP will reject the reference time for a while. In the latter case, the operating system's clock will continue with the last corrections effective while the new reference time is being rejected. After some time, small offsets (significantly less than a second) will be slewed (adjusted slowly), while larger offsets will cause the clock to be stepped (set anew). Huge offsets are rejected, and NTP will terminate itself, believing something very strange must have happened. |