From ab243e50e18188327f4d105bea528f493748b3df Mon Sep 17 00:00:00 2001
From: Matthias Kaeppler <mkaeppler@gitlab.com>
Date: Wed, 19 Jan 2022 14:48:38 +0100
Subject: [PATCH] RubySampler: allow specifying metrics prefix
This prevents metric names from clashing in cases
where multiple processes emit the same metrics
to the same scraper job and which do not have
a pid label.
---
lib/gitlab/metrics/samplers/ruby_sampler.rb | 36 ++++++++++---------
metrics_server/metrics_server.rb | 2 +-
.../metrics/samplers/ruby_sampler_spec.rb | 14 ++++++++
3 files changed, 35 insertions(+), 17 deletions(-)
diff --git a/lib/gitlab/metrics/samplers/ruby_sampler.rb b/lib/gitlab/metrics/samplers/ruby_sampler.rb
index d71ee671b8d42..4a3ef3711a508 100644
--- a/lib/gitlab/metrics/samplers/ruby_sampler.rb
+++ b/lib/gitlab/metrics/samplers/ruby_sampler.rb
@@ -7,22 +7,20 @@ class RubySampler < BaseSampler
DEFAULT_SAMPLING_INTERVAL_SECONDS = 60
GC_REPORT_BUCKETS = [0.01, 0.05, 0.1, 0.2, 0.3, 0.5, 1].freeze
- def initialize(...)
+ def initialize(prefix: nil, **options)
+ @prefix = prefix
+
GC::Profiler.clear
metrics[:process_start_time_seconds].set(labels, Time.now.to_i)
- super(...)
+ super(**options)
end
def metrics
@metrics ||= init_metrics
end
- def with_prefix(prefix, name)
- "ruby_#{prefix}_#{name}".to_sym
- end
-
def to_doc_string(name)
name.to_s.humanize
end
@@ -33,19 +31,19 @@ def labels
def init_metrics
metrics = {
- file_descriptors: ::Gitlab::Metrics.gauge(with_prefix(:file, :descriptors), 'File descriptors used', labels),
- process_cpu_seconds_total: ::Gitlab::Metrics.gauge(with_prefix(:process, :cpu_seconds_total), 'Process CPU seconds total'),
- process_max_fds: ::Gitlab::Metrics.gauge(with_prefix(:process, :max_fds), 'Process max fds'),
- process_resident_memory_bytes: ::Gitlab::Metrics.gauge(with_prefix(:process, :resident_memory_bytes), 'Memory used (RSS)', labels),
- process_unique_memory_bytes: ::Gitlab::Metrics.gauge(with_prefix(:process, :unique_memory_bytes), 'Memory used (USS)', labels),
- process_proportional_memory_bytes: ::Gitlab::Metrics.gauge(with_prefix(:process, :proportional_memory_bytes), 'Memory used (PSS)', labels),
- process_start_time_seconds: ::Gitlab::Metrics.gauge(with_prefix(:process, :start_time_seconds), 'Process start time seconds'),
- sampler_duration: ::Gitlab::Metrics.counter(with_prefix(:sampler, :duration_seconds_total), 'Sampler time', labels),
- gc_duration_seconds: ::Gitlab::Metrics.histogram(with_prefix(:gc, :duration_seconds), 'GC time', labels, GC_REPORT_BUCKETS)
+ file_descriptors: ::Gitlab::Metrics.gauge(metric_name(:file, :descriptors), 'File descriptors used', labels),
+ process_cpu_seconds_total: ::Gitlab::Metrics.gauge(metric_name(:process, :cpu_seconds_total), 'Process CPU seconds total'),
+ process_max_fds: ::Gitlab::Metrics.gauge(metric_name(:process, :max_fds), 'Process max fds'),
+ process_resident_memory_bytes: ::Gitlab::Metrics.gauge(metric_name(:process, :resident_memory_bytes), 'Memory used (RSS)', labels),
+ process_unique_memory_bytes: ::Gitlab::Metrics.gauge(metric_name(:process, :unique_memory_bytes), 'Memory used (USS)', labels),
+ process_proportional_memory_bytes: ::Gitlab::Metrics.gauge(metric_name(:process, :proportional_memory_bytes), 'Memory used (PSS)', labels),
+ process_start_time_seconds: ::Gitlab::Metrics.gauge(metric_name(:process, :start_time_seconds), 'Process start time seconds'),
+ sampler_duration: ::Gitlab::Metrics.counter(metric_name(:sampler, :duration_seconds_total), 'Sampler time', labels),
+ gc_duration_seconds: ::Gitlab::Metrics.histogram(metric_name(:gc, :duration_seconds), 'GC time', labels, GC_REPORT_BUCKETS)
}
GC.stat.keys.each do |key|
- metrics[key] = ::Gitlab::Metrics.gauge(with_prefix(:gc_stat, key), to_doc_string(key), labels)
+ metrics[key] = ::Gitlab::Metrics.gauge(metric_name(:gc_stat, key), to_doc_string(key), labels)
end
metrics
@@ -65,6 +63,12 @@ def sample
private
+ def metric_name(group, metric)
+ name = "ruby_#{group}_#{metric}"
+ name = "#{@prefix}_#{name}" if @prefix.present?
+ name.to_sym
+ end
+
def sample_gc
# Observe all GC samples
sample_gc_reports.each do |report|
diff --git a/metrics_server/metrics_server.rb b/metrics_server/metrics_server.rb
index 122a4e4fc1e78..68d39eaf77c2d 100644
--- a/metrics_server/metrics_server.rb
+++ b/metrics_server/metrics_server.rb
@@ -50,7 +50,7 @@ def start
# 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(warmup: true).start
+ Gitlab::Metrics::Samplers::RubySampler.initialize_instance(prefix: name, warmup: true).start
exporter_class = "Gitlab::Metrics::Exporter::#{@target.camelize}Exporter".constantize
settings = Settings.new(Settings.monitoring[name])
diff --git a/spec/lib/gitlab/metrics/samplers/ruby_sampler_spec.rb b/spec/lib/gitlab/metrics/samplers/ruby_sampler_spec.rb
index a4877208bcf22..dfae5aa678450 100644
--- a/spec/lib/gitlab/metrics/samplers/ruby_sampler_spec.rb
+++ b/spec/lib/gitlab/metrics/samplers/ruby_sampler_spec.rb
@@ -18,6 +18,20 @@
expect(sampler.metrics[:process_start_time_seconds].get).to eq(Time.now.to_i)
end
end
+
+ context 'when not setting a prefix' do
+ it 'does not prepend metrics with that prefix' do
+ expect(sampler.metrics[:process_start_time_seconds].name).to eq(:ruby_process_start_time_seconds)
+ end
+ end
+
+ context 'when using custom prefix' do
+ let(:sampler) { described_class.new(prefix: 'custom') }
+
+ it 'prepends metrics with that prefix' do
+ expect(sampler.metrics[:process_start_time_seconds].name).to eq(:custom_ruby_process_start_time_seconds)
+ end
+ end
end
describe '#sample' do
--
GitLab