aboutsummaryrefslogtreecommitdiffstats
path: root/util/statsd.lua
blob: 6ae85c31a89252fd127efbf85231c4a9b289d2ff (plain)
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
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
local socket = require "socket";
local time = require "util.time".now;
local array = require "util.array";
local t_concat = table.concat;

local new_metric_registry = require "util.openmetrics".new_metric_registry;
local render_histogram_le = require "util.openmetrics".render_histogram_le;

-- BEGIN of Metric implementations

-- Gauges
local gauge_metric_mt = {}
gauge_metric_mt.__index = gauge_metric_mt

local function new_gauge_metric(full_name, impl)
	local metric = {
		_full_name = full_name;
		_impl = impl;
		value = 0;
	}
	setmetatable(metric, gauge_metric_mt)
	return metric
end

function gauge_metric_mt:set(value)
	self.value = value
	self._impl:push_gauge(self._full_name, value)
end

function gauge_metric_mt:add(delta)
	self.value = self.value + delta
	self._impl:push_gauge(self._full_name, self.value)
end

function gauge_metric_mt:reset()
	self.value = 0
	self._impl:push_gauge(self._full_name, 0)
end

function gauge_metric_mt.iter_samples()
	-- statsd backend does not support iteration.
	return function()
		return nil
	end
end

-- Counters
local counter_metric_mt = {}
counter_metric_mt.__index = counter_metric_mt

local function new_counter_metric(full_name, impl)
	local metric = {
		_full_name = full_name,
		_impl = impl,
		value = 0,
	}
	setmetatable(metric, counter_metric_mt)
	return metric
end

function counter_metric_mt:set(value)
	local delta = value - self.value
	self.value = value
	self._impl:push_counter_delta(self._full_name, delta)
end

function counter_metric_mt:add(value)
	self.value = (self.value or 0) + value
	self._impl:push_counter_delta(self._full_name, value)
end

function counter_metric_mt.iter_samples()
	-- statsd backend does not support iteration.
	return function()
		return nil
	end
end

function counter_metric_mt:reset()
	self.value = 0
end

-- Histograms
local histogram_metric_mt = {}
histogram_metric_mt.__index = histogram_metric_mt

local function new_histogram_metric(buckets, full_name, impl)
	-- NOTE: even though the more or less proprietrary dogstatsd has its own
	-- histogram implementation, we push the individual buckets in this statsd
	-- backend for both consistency and compatibility across statsd
	-- implementations.
	local metric = {
		_sum_name = full_name..".sum",
		_count_name = full_name..".count",
		_impl = impl,
		_created = time(),
		_sum = 0,
		_count = 0,
	}
	-- the order of buckets matters unfortunately, so we cannot directly use
	-- the thresholds as table keys
	for i, threshold in ipairs(buckets) do
		local threshold_s = render_histogram_le(threshold)
		metric[i] = {
			threshold = threshold,
			threshold_s = threshold_s,
			count = 0,
			_full_name = full_name..".bucket."..(threshold_s:gsub("%.", "_")),
		}
	end
	setmetatable(metric, histogram_metric_mt)
	return metric
end

function histogram_metric_mt:sample(value)
	-- According to the I-D, values must be part of all buckets
	for i, bucket in pairs(self) do
		if "number" == type(i) and value <= bucket.threshold then
			bucket.count = bucket.count + 1
			self._impl:push_counter_delta(bucket._full_name, 1)
		end
	end
	self._sum = self._sum + value
	self._count = self._count + 1
	self._impl:push_gauge(self._sum_name, self._sum)
	self._impl:push_counter_delta(self._count_name, 1)
end

function histogram_metric_mt.iter_samples()
	-- statsd backend does not support iteration.
	return function()
		return nil
	end
end

function histogram_metric_mt:reset()
	self._created = time()
	self._count = 0
	self._sum = 0
	for i, bucket in pairs(self) do
		if "number" == type(i) then
			bucket.count = 0
		end
	end
	self._impl:push_gauge(self._sum_name, self._sum)
end

-- Summaries
local summary_metric_mt = {}
summary_metric_mt.__index = summary_metric_mt

local function new_summary_metric(full_name, impl)
	local metric = {
		_sum_name = full_name..".sum",
		_count_name = full_name..".count",
		_impl = impl,
	}
	setmetatable(metric, summary_metric_mt)
	return metric
end

function summary_metric_mt:sample(value)
	self._impl:push_counter_delta(self._sum_name, value)
	self._impl:push_counter_delta(self._count_name, 1)
end

function summary_metric_mt.iter_samples()
	-- statsd backend does not support iteration.
	return function()
		return nil
	end
end

function summary_metric_mt.reset()
end

-- BEGIN of statsd client implementation

local statsd_mt = {}
statsd_mt.__index = statsd_mt

function statsd_mt:cork()
	self.corked = true
	self.cork_buffer = self.cork_buffer or {}
end

function statsd_mt:uncork()
	self.corked = false
	self:_flush_cork_buffer()
end

function statsd_mt:_flush_cork_buffer()
	local buffer = self.cork_buffer
	for metric_name, value in pairs(buffer) do
		self:_send_gauge(metric_name, value)
		buffer[metric_name] = nil
	end
end

function statsd_mt:push_gauge(metric_name, value)
	if self.corked then
		self.cork_buffer[metric_name] = value
	else
		self:_send_gauge(metric_name, value)
	end
end

function statsd_mt:_send_gauge(metric_name, value)
	self:_send(self.prefix..metric_name..":"..tostring(value).."|g")
end

function statsd_mt:push_counter_delta(metric_name, delta)
	self:_send(self.prefix..metric_name..":"..tostring(delta).."|c")
end

function statsd_mt:_send(s)
	return self.sock:send(s)
end

-- END of statsd client implementation

local function build_metric_name(family_name, labels)
	local parts = array { family_name }
	if labels then
		parts:append(labels)
	end
	return t_concat(parts, "/"):gsub("%.", "_"):gsub("/", ".")
end

local function new(config)
	if not config or not config.statsd_server then
		return nil, "No statsd server specified in the config, please see https://prosody.im/doc/statistics";
	end

	local sock = socket.udp();
	sock:setpeername(config.statsd_server, config.statsd_port or 8125);

	local prefix = (config.prefix or "prosody")..".";

	local impl = {
		metric_registry = nil;
		sock = sock;
		prefix = prefix;
	};
	setmetatable(impl, statsd_mt)

	local backend = {
		gauge = function(family_name, labels)
			return new_gauge_metric(build_metric_name(family_name, labels), impl)
		end;
		counter = function(family_name, labels)
			return new_counter_metric(build_metric_name(family_name, labels), impl)
		end;
		histogram = function(buckets, family_name, labels)
			return new_histogram_metric(buckets, build_metric_name(family_name, labels), impl)
		end;
		summary = function(family_name, labels, extra)
			return new_summary_metric(build_metric_name(family_name, labels), impl, extra)
		end;
	};

	impl.metric_registry = new_metric_registry(backend);

	return impl;
end

return {
	new = new;
}