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
|
# frozen_string_literal: true
require_relative '../config/boot'
class MetricsServer # rubocop:disable Gitlab/NamespacedClass
# The singleton instance used to supervise the Puma metrics server.
PumaProcessSupervisor = Class.new(Gitlab::ProcessSupervisor)
class << self
def start_for_puma
metrics_dir = ::Prometheus::Client.configuration.multiprocess_files_dir
start_server = proc do
MetricsServer.spawn('puma', metrics_dir: metrics_dir).tap do |pid|
Gitlab::AppLogger.info("Starting Puma metrics server with pid #{pid}")
end
end
supervisor = PumaProcessSupervisor.instance
at_exit do
Gitlab::AppLogger.info("Puma process #{Process.pid} is exiting, shutting down metrics server...")
supervisor.shutdown
end
supervisor.supervise(start_server.call) do
Gitlab::AppLogger.info('Puma metrics server terminated, restarting...')
start_server.call
end
end
def start_for_sidekiq(**options)
self.fork('sidekiq', **options)
end
def spawn(target, metrics_dir:, wipe_metrics_dir: false)
ensure_valid_target!(target)
cmd = "#{Rails.root}/bin/metrics-server"
env = {
'METRICS_SERVER_TARGET' => target,
'WIPE_METRICS_DIR' => wipe_metrics_dir ? '1' : '0',
'GITLAB_CONFIG' => ENV['GITLAB_CONFIG']
}
Process.spawn(env, cmd, err: $stderr, out: $stdout, pgroup: true).tap do |pid|
Process.detach(pid)
end
end
def fork(target, metrics_dir:, wipe_metrics_dir: false, reset_signals: [])
ensure_valid_target!(target)
pid = Process.fork
if pid.nil? # nil means we're inside the fork
# Remove any custom signal handlers the parent process had registered, since we do
# not want to inherit them, and Ruby forks with a `clone` that has the `CLONE_SIGHAND`
# flag set.
Gitlab::ProcessManagement.modify_signals(reset_signals, 'DEFAULT')
server = MetricsServer.new(target, metrics_dir, wipe_metrics_dir)
# This rewrites /proc/cmdline, since otherwise tools like `top` will show the
# parent process `cmdline` which is really confusing.
$0 = server.name
server.start
else
Process.detach(pid)
end
pid
end
def name(target)
case target
when 'puma' then 'web_exporter'
when 'sidekiq' then 'sidekiq_exporter'
else ensure_valid_target!(target)
end
end
private
# We need to use `.` (dot) notation to access the updates we did in `config/initializers/1_settings.rb`
# For that reason, avoid using `[]` ("optional/dynamic settings notation") to resolve it dynamically.
# Refer to https://gitlab.com/gitlab-org/gitlab/-/issues/386865
def settings_value(target)
case target
when 'puma' then ::Settings.monitoring.web_exporter
when 'sidekiq' then ::Settings.monitoring.sidekiq_exporter
else ensure_valid_target!(target)
end
end
def ensure_valid_target!(target)
raise "Target must be one of [puma,sidekiq]" unless %w[puma sidekiq].include?(target)
end
end
def initialize(target, metrics_dir, wipe_metrics_dir)
@target = target
@metrics_dir = metrics_dir
@wipe_metrics_dir = wipe_metrics_dir
end
def start
::Prometheus::Client.configure do |config|
config.multiprocess_files_dir = @metrics_dir
config.pid_provider = proc { name }
end
FileUtils.mkdir_p(@metrics_dir, mode: 0700)
::Prometheus::CleanupMultiprocDirService.new(@metrics_dir).execute if @wipe_metrics_dir
# We need to `warmup: true` since otherwise the sampler and exporter threads enter
# a race where not all Prometheus db files will be visible to the exporter, resulting
# in missing metrics.
# Warming up ensures that these files exist prior to the exporter starting up.
Gitlab::Metrics::Samplers::RubySampler.initialize_instance(prefix: name, warmup: true).start
default_opts = { gc_requests: true, synchronous: true }
exporter =
case @target
when 'puma'
Gitlab::Metrics::Exporter::WebExporter.instance(**default_opts)
when 'sidekiq'
settings = GitlabSettings::Options.build(Settings.monitoring.sidekiq_exporter)
Gitlab::Metrics::Exporter::SidekiqExporter.instance(settings, **default_opts)
end
exporter.start
end
def name
self.class.name(@target)
end
end
|
