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spec/util_array_spec.lua @ 11523:5f15ab7c6ae5
Statistics: Rewrite statistics backends to use OpenMetrics
The metric subsystem of Prosody has had some shortcomings from
the perspective of the current state-of-the-art in metric
observability.
The OpenMetrics standard [0] is a formalization of the data
model (and serialization format) of the well-known and
widely-used Prometheus [1] software stack.
The previous stats subsystem of Prosody did not map well to that
format (see e.g. [2] and [3]); the key reason is that it was
trying to do too much math on its own ([2]) while lacking
first-class support for "families" of metrics ([3]) and
structured metric metadata (despite the `extra` argument to
metrics, there was no standard way of representing common things
like "tags" or "labels").
Even though OpenMetrics has grown from the Prometheus world of
monitoring, it maps well to other popular monitoring stacks
such as:
- InfluxDB (labels can be mapped to tags and fields as necessary)
- Carbon/Graphite (labels can be attached to the metric name with
dot-separation)
- StatsD (see graphite when assuming that graphite is used as
backend, which is the default)
The util.statsd module has been ported to use the OpenMetrics
model as a proof of concept. An implementation which exposes
the util.statistics backend data as Prometheus metrics is
ready for publishing in prosody-modules (most likely as
mod_openmetrics_prometheus to avoid breaking existing 0.11
deployments).
At the same time, the previous measure()-based API had one major
advantage: It is really simple and easy to use without requiring
lots of knowledge about OpenMetrics or similar concepts. For that
reason as well as compatibility with existing code, it is preserved
and may even be extended in the future.
However, code relying on the `stats-updated` event as well as
`get_stats` from `statsmanager` will break because the data
model has changed completely; in case of `stats-updated`, the
code will simply not run (as the event was renamed in order
to avoid conflicts); the `get_stats` function has been removed
completely (so it will cause a traceback when it is attempted
to be used).
Note that the measure_*_event methods have been removed from
the module API. I was unable to find any uses or documentation
and thus deemed they should not be ported. Re-implementation is
possible when necessary.
[0]: https://openmetrics.io/
[1]: https://prometheus.io/
[2]: #959
[3]: #960
author | Jonas Schäfer <jonas@wielicki.name> |
---|---|
date | Sun, 18 Apr 2021 11:47:41 +0200 (2021-04-18) |
parent | 10590:257dc26e8e65 |
child | 11787:3ae6fa901a8b |
rev | line source |
---|---|
10100 | 1 local array = require "util.array"; |
2 describe("util.array", function () | |
3 describe("creation", function () | |
10397 | 4 describe("from table", function () |
10100 | 5 it("works", function () |
6 local a = array({"a", "b", "c"}); | |
7 assert.same({"a", "b", "c"}, a); | |
8 end); | |
9 end); | |
10 | |
11 describe("from iterator", function () | |
12 it("works", function () | |
13 -- collects the first value, ie the keys | |
14 local a = array(ipairs({true, true, true})); | |
15 assert.same({1, 2, 3}, a); | |
16 end); | |
17 end); | |
18 | |
19 describe("collect", function () | |
20 it("works", function () | |
21 -- collects the first value, ie the keys | |
22 local a = array.collect(ipairs({true, true, true})); | |
23 assert.same({1, 2, 3}, a); | |
24 end); | |
25 end); | |
26 | |
27 end); | |
28 | |
29 describe("metatable", function () | |
30 describe("operator", function () | |
31 describe("addition", function () | |
32 it("works", function () | |
33 local a = array({ "a", "b" }); | |
34 local b = array({ "c", "d" }); | |
35 assert.same({"a", "b", "c", "d"}, a + b); | |
36 end); | |
37 end); | |
38 | |
39 describe("equality", function () | |
40 it("works", function () | |
41 local a1 = array({ "a", "b" }); | |
42 local a2 = array({ "a", "b" }); | |
43 local b = array({ "c", "d" }); | |
44 assert.truthy(a1 == a2); | |
45 assert.falsy(a1 == b); | |
10590
257dc26e8e65
util.array: Add a test case for a behavior change in Lua 5.3
Kim Alvefur <zash@zash.se>
parents:
10397
diff
changeset
|
46 assert.falsy(a1 == { "a", "b" }, "Behavior of metatables changed in Lua 5.3"); |
10100 | 47 end); |
48 end); | |
49 | |
50 describe("division", function () | |
51 it("works", function () | |
52 local a = array({ "a", "b", "c" }); | |
53 local b = a / function (i) if i ~= "b" then return i .. "x" end end; | |
54 assert.same({ "ax", "cx" }, b); | |
55 end); | |
56 end); | |
57 | |
58 end); | |
59 end); | |
60 | |
61 describe("methods", function () | |
62 describe("map", function () | |
63 it("works", function () | |
64 local a = array({ "a", "b", "c" }); | |
65 local b = a:map(string.upper); | |
66 assert.same({ "A", "B", "C" }, b); | |
67 end); | |
68 end); | |
69 | |
70 describe("filter", function () | |
71 it("works", function () | |
72 local a = array({ "a", "b", "c" }); | |
73 a:filter(function (i) return i ~= "b" end); | |
74 assert.same({ "a", "c" }, a); | |
75 end); | |
76 end); | |
77 | |
78 describe("sort", function () | |
79 it("works", function () | |
80 local a = array({ 5, 4, 3, 1, 2, }); | |
81 a:sort(); | |
82 assert.same({ 1, 2, 3, 4, 5, }, a); | |
83 end); | |
84 end); | |
85 | |
86 describe("unique", function () | |
87 it("works", function () | |
88 local a = array({ "a", "b", "c", "c", "a", "b" }); | |
89 a:unique(); | |
90 assert.same({ "a", "b", "c" }, a); | |
91 end); | |
92 end); | |
93 | |
94 describe("pluck", function () | |
95 it("works", function () | |
96 local a = array({ { a = 1, b = -1 }, { a = 2, b = -2 }, }); | |
97 a:pluck("a"); | |
98 assert.same({ 1, 2 }, a); | |
99 end); | |
100 end); | |
101 | |
102 | |
103 describe("reverse", function () | |
104 it("works", function () | |
105 local a = array({ "a", "b", "c" }); | |
106 a:reverse(); | |
107 assert.same({ "c", "b", "a" }, a); | |
108 end); | |
109 end); | |
110 | |
111 -- TODO :shuffle | |
112 | |
113 describe("append", function () | |
114 it("works", function () | |
115 local a = array({ "a", "b", "c" }); | |
116 a:append(array({ "d", "e", })); | |
117 assert.same({ "a", "b", "c", "d", "e" }, a); | |
118 end); | |
119 end); | |
120 | |
121 describe("push", function () | |
122 it("works", function () | |
123 local a = array({ "a", "b", "c" }); | |
124 a:push("d"):push("e"); | |
125 assert.same({ "a", "b", "c", "d", "e" }, a); | |
126 end); | |
127 end); | |
128 | |
129 describe("pop", function () | |
130 it("works", function () | |
131 local a = array({ "a", "b", "c" }); | |
132 assert.equal("c", a:pop()); | |
133 assert.same({ "a", "b", }, a); | |
134 end); | |
135 end); | |
136 | |
137 describe("concat", function () | |
138 it("works", function () | |
139 local a = array({ "a", "b", "c" }); | |
140 assert.equal("a,b,c", a:concat(",")); | |
141 end); | |
142 end); | |
143 | |
144 describe("length", function () | |
145 it("works", function () | |
146 local a = array({ "a", "b", "c" }); | |
147 assert.equal(3, a:length()); | |
148 end); | |
149 end); | |
150 | |
151 end); | |
152 | |
153 -- TODO The various array.foo(array ina, array outa) functions | |
154 end); | |
155 |