telegraf/plugins/inputs/ntpq/README.md

ntpq Input Plugin

Get standard NTP query metrics, requires ntpq executable.

Below is the documentation of the various headers returned from the NTP query command when running ntpq -p.

• remote – The remote peer or server being synced to. “LOCAL” is this local host (included in case there are no remote peers or servers available);
• refid – Where or what the remote peer or server is itself synchronised to;
• st (stratum) – The remote peer or server Stratum
• t (type) – Type (u: unicast or manycast client, b: broadcast or multicast client, l: local reference clock, s: symmetric peer, A: manycast server, B: broadcast server, M: multicast server, see “Automatic Server Discovery“);
• when – When last polled (seconds ago, “h” hours ago, or “d” days ago);
• poll – Polling frequency: rfc5905 suggests this ranges in NTPv4 from 4 (16s) to 17 (36h) (log2 seconds), however observation suggests the actual displayed value is seconds for a much smaller range of 64 (26) to 1024 (210) seconds;
• reach – An 8-bit left-shift shift register value recording polls (bit set = successful, bit reset = fail) displayed in octal;
• delay – Round trip communication delay to the remote peer or server (milliseconds);
• offset – Mean offset (phase) in the times reported between this local host and the remote peer or server (RMS, milliseconds);
• jitter – Mean deviation (jitter) in the time reported for that remote peer or server (RMS of difference of multiple time samples, milliseconds);

Configuration:

# Get standard NTP query metrics, requires ntpq executable
[[inputs.ntpq]]
  ## If false, set the -n ntpq flag. Can reduce metric gather times.
  dns_lookup = true

Measurements & Fields:

• ntpq
  • delay (float, milliseconds)
  • jitter (float, milliseconds)
  • offset (float, milliseconds)
  • poll (int, seconds)
  • reach (int)
  • when (int, seconds)

Tags:

• All measurements have the following tags:
  • refid
  • remote
  • type
  • stratum

Example Output:

$ telegraf --config ~/ws/telegraf.conf --input-filter ntpq --test
* Plugin: ntpq, Collection 1
> ntpq,refid=.GPSs.,remote=*time.apple.com,stratum=1,type=u delay=91.797,jitter=3.735,offset=12.841,poll=64i,reach=377i,when=35i 1457960478909556134