1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178
|
-- SPDX-License-Identifier: GPL-3.0-or-later
-- Module implementation
local M = {
namespace = '',
finalize = function (_ --[[metrics]]) end,
}
-- Gauge metrics
local gauges = {
['worker.concurrent'] = true,
['worker.rss'] = true,
}
local function merge(t, results, prefix)
for _, result in pairs(results) do
if type(result) == 'table' then
for k, v in pairs(result) do
local val = t[prefix..k]
t[prefix..k] = (val or 0) + v
end
end
end
end
local function getstats()
local t = {}
merge(t, map 'stats.list()', '')
merge(t, map 'cache.stats()', 'cache.')
merge(t, map 'worker.stats()', 'worker.')
return t
end
-- @returns current stats + difference against previous data set passed in @param prev
local function snapshot_start(prev)
assert(type(prev) == 'table', 'table with previous values expected')
local is_empty = true
-- Get current snapshot
local cur, stats_dt = getstats(), {}
for k,v in pairs(cur) do
if gauges[k] then
stats_dt[k] = v
else
stats_dt[k] = v - (prev[k] or 0)
end
is_empty = is_empty and stats_dt[k] == 0
end
-- Calculate upstreams and geotag them if possible
local upstreams
if http.geoip then
upstreams = stats.upstreams()
for k,v in pairs(upstreams) do
local gi
if string.find(k, '.', 1, true) then
gi = http.geoip:search_ipv4(k)
else
gi = http.geoip:search_ipv6(k)
end
if gi then
upstreams[k] = {data=v, location=gi.location, country=gi.country and gi.country.iso_code}
end
end
end
-- Aggregate per-worker metrics
local wdata = {}
for _, info in pairs(map 'worker.info()') do
if type(info) == 'table' then
wdata[tostring(info.pid)] = {
rss = info.rss,
usertime = info.usertime,
systime = info.systime,
pagefaults = info.pagefaults,
queries = info.queries
}
end
end
-- Publish stats updates periodically
if not is_empty then
local update = {time=os.time(), stats=stats_dt, upstreams=upstreams, workers=wdata}
return cur, update
end
return cur, nil
end
-- Function to sort frequency list
local function stream_stats(_, ws)
local ok = true
-- Publish stats updates periodically
local prev = getstats()
while ok do
worker.sleep(1)
local update
prev, update = snapshot_start(prev)
local push = tojson(update)
ok = ws:send(push)
end
end
-- Transform metrics from Graphite to Prometheus format
-- See: https://gitlab.nic.cz/knot/knot-resolver/-/issues/650
-- E.g.:
-- worker.ipv4 -> worker_ipv4
-- answer.blocked;stype=A -> answer_blocked{stype="A"}
local function get_metric(key)
local key_index, key_len, key_tag = 0, #key, 0
return select(1, key:gsub('.', function (c)
key_index = key_index + 1
if key_tag == 0 then
if c == '.' then return '_' end
if c == ';' then key_tag = 1; return '{' end
elseif key_tag == 1 then
if key_index == key_len then
if c == '=' then return '=""}'
else return c .. '"}' end
end
if c == '=' then key_tag = 2; return '="' end
elseif key_tag == 2 then
if key_index == key_len then
if c == ';' then return '"}'
else return c .. '"}' end
end
if c == ';' then key_tag = 1; return '",' end
end
return nil
end))
end
-- Render stats in Prometheus text format
local function serve_prometheus()
-- First aggregate metrics list and print counters
local slist, render = getstats(), {}
local latency = {}
local counter = '# TYPE %s counter\n%s %f'
for k,v in pairs(slist) do
k = get_metric(k)
-- Aggregate histograms
local band = k:match('answer_([%d]+)ms')
if band then
table.insert(latency, {band, v})
elseif k == 'answer_slow' then
table.insert(latency, {'+Inf', v})
-- Counter as a fallback
else
local key = M.namespace .. k
local name, label = key:match('^([^{]+)(.*)$')
table.insert(render, string.format(counter, name, name .. label, v))
end
end
-- Fill in latency histogram
local function kweight(x) return tonumber(x) or math.huge end
table.sort(latency, function (a,b) return kweight(a[1]) < kweight(b[1]) end)
table.insert(render, string.format('# TYPE %slatency histogram', M.namespace))
local count, sum = 0.0, 0.0
for _,e in ipairs(latency) do
-- The information about the %Inf bin is lost, so we treat it
-- as a timeout (3000ms) for metrics purposes
count = count + e[2]
sum = sum + e[2] * (math.min(tonumber(e[1]), 3000.0))
table.insert(render, string.format('%slatency_bucket{le="%s"} %f', M.namespace, e[1], count))
end
table.insert(render, string.format('%slatency_count %f', M.namespace, count))
table.insert(render, string.format('%slatency_sum %f', M.namespace, sum))
-- Finalize metrics table before rendering
if type(M.finalize) == 'function' then
M.finalize(render)
end
return table.concat(render, '\n') .. '\n'
end
-- Export module interface
M.endpoints = {
['/stats'] = {'application/json', getstats, stream_stats},
['/frequent'] = {'application/json', function () return stats.frequent() end},
['/upstreams'] = {'application/json', function () return stats.upstreams() end},
['/bogus'] = {'application/json', function () return bogus_log.frequent() end},
['/metrics'] = {'text/plain; version=0.0.4', serve_prometheus},
}
return M
|