ntppeerstats.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
#  ntppeerstats.py
#
#  Copyright 2016 Christopher Arndt <chris- at- chrisarndt -dot- de>
#
"""Get NTP daemon peer statistics and graph time offsets.

Documentation of the file format:

http://doc.ntp.org/current-stable/monopt.html

Documentation about the Modified Julian Date used there:

http://tycho.usno.navy.mil/mjd.html

To prepare the peerstats files as written out by the NTP server
and and left by logrotation to one big input file for this script:

    $ rsync -rv --update example.com:/var/log/ntpstats/ .
    $ zcat peerstats.*.gz | cat - peerstats.???????? peerstats | \
          sort -n > peerstats-all

"""

from __future__ import print_function, unicode_literals

import argparse
import logging
import sys
import time

from collections import namedtuple
from datetime import datetime, timedelta

import pandas as pd
from matplotlib import pyplot as pl
# https://gist.github.com/jiffyclub/1294443
from jdutil import mjd_to_jd, jd_to_date


log = logging.getLogger('ntppeerstats')
Peerstat = namedtuple("Peerstat",
     "timestamp day seconds address status offset delay dispersion skew")
types = (int, float, str, lambda x: int(x, 16), float, float, float, float)


def mjd_seconds_to_dt(mjd, seconds):
    year, month, day = jd_to_date(mjd_to_jd(mjd))
    return (datetime(year, month, int(day)) + timedelta(seconds=seconds))


def read_peerstats(filename):
    with open(filename) as fp:
        for lineno, line in enumerate(fp):
            values = [f(x) for f, x in zip(types, line.strip().split())]
            try:
                timestamp = mjd_seconds_to_dt(values[0], values[1])
            except:
                log.exception("Could not parse date on line %i: day=%i, "
                    "seconds=%f", lineno, values[0], values[1])
                timestamp = None

            stat = Peerstat(*[timestamp] + values)
            yield stat


def main(args=None):
    ap = argparse.ArgumentParser(description=__doc__.splitlines()[0])
    ap.add_argument('-v', '--verbose', action="store_true",
        help="Be verbose")
    ap.add_argument('peerstats', default="/var/log/ntpstats/peerstats",
        help="Path of peerstats file")

    args = ap.parse_args(args if args is not None else sys.argv[1:])

    logging.basicConfig(format="%(levelname)s: %(message)s",
        level=logging.DEBUG if args.verbose else logging.INFO)

    s = time.time()
    peerstats = read_peerstats(args.peerstats)
    ps = pd.DataFrame.from_records(peerstats, columns=Peerstat._fields)
    d = time.time() - s
    log.debug("Read peerstats in %0.4f sec." % d)

    #ps.info()
    #print()
    print(ps[['offset', 'delay', 'dispersion', 'skew']].describe())

    ax = pl.gca()
    for _, group in ps.groupby('address'):
        group.plot(x='timestamp', y='offset', ax=ax)

    pl.show()


if __name__ == '__main__':
    sys.exit(main(sys.argv[1:]) or 0)