3
# copy .rrd files from a remote munin master host, sum the 'df' stats from a
4
# list of hosts, use them to estimate a rate-of-change for the past month,
5
# then extrapolate to guess how many weeks/months/years of storage space we
6
# have left, and output it to another munin graph
11
MUNIN_HOST = "munin.allmydata.com"
12
PREFIX = "%s:/var/lib/munin/prodtahoe/" % MUNIN_HOST
13
FILES = [ "prodtahoe%d.allmydata.com-df-_dev_sd%s3-g.rrd" % (a,b)
15
for b in ("a", "b", "c", "d")
17
REMOTEFILES = [ PREFIX + f for f in FILES ]
18
LOCALFILES = ["/var/lib/munin/prodtahoe/" + f for f in FILES ]
19
WEBFILE = "/var/www/tahoe/spacetime.json"
23
# copy the RRD files from your munin master host to a local one
24
cmd = "rsync %s rrds/" % (" ".join(REMOTEFILES))
29
return time.strftime("%b %d %H:%M", time.localtime(t))
31
def predict_future(past_s):
38
d = rrdtool.fetch(fn, "AVERAGE", "-s", "-"+past_s, "-e", "-1hr")
39
# ((start, end, step), (name1, name2, ...), [(data1, data2, ..), ...])
40
(start_time, end_time ,step) = d[0]
41
#print format_time(start_time), " - ", format_time(end_time), step
46
start_space = d[2][0][0]
47
if start_space is None:
49
# I don't know why, but the last few points are always bogus. Running
50
# 'rrdtool fetch' on the command line is usually ok.. I blame the python
52
end_space = d[2][-4][0]
55
end_time = end_time - (4*step)
56
start_df.append(start_space)
57
end_df.append(end_space)
58
durations.append(end_time - start_time)
60
avg_start_df = sum(start_df) / len(start_df)
61
avg_end_df = sum(end_df) / len(end_df)
62
avg_duration = sum(durations) / len(durations)
63
#print avg_start_df, avg_end_df, avg_duration
65
rate = (avg_end_df - avg_start_df) / avg_duration
66
#print "Rate", rate, " %/s"
67
#print "measured over", avg_duration / 86400, "days"
68
remaining = 100 - avg_end_df
69
remaining_seconds = remaining / rate
70
#print "remaining seconds", remaining_seconds
71
remaining_days = remaining_seconds / 86400
72
#print "remaining days", remaining_days
75
def write_to_file(samples):
76
# write a JSON-formatted dictionary
77
f = open(WEBFILE + ".tmp", "w")
79
f.write(", ".join(['"%s": %s' % (k, samples[k])
80
for k in sorted(samples.keys())]))
83
os.rename(WEBFILE + ".tmp", WEBFILE)
85
if len(sys.argv) > 1 and sys.argv[1] == "config":
87
graph_title Tahoe Remaining Space Predictor
88
graph_vlabel days remaining
90
graph_info This graph shows the estimated number of days left until storage space is exhausted
91
days_2wk.label days left (2wk sample)
93
days_4wk.label days left (4wk sample)
94
days_4wk.draw LINE2"""
99
remaining_4wk = predict_future("4wk")
100
if remaining_4wk is not None:
101
print "days_4wk.value", remaining_4wk
102
samples["remaining_4wk"] = remaining_4wk
103
remaining_2wk = predict_future("2wk")
104
if remaining_2wk is not None:
105
print "days_2wk.value", remaining_2wk
106
samples["remaining_2wk"] = remaining_2wk
107
write_to_file(samples)