gitlab-org--gitlab-foss/lib/gitlab/metrics/samplers/threads_sampler.rb

78 lines
2.6 KiB
Ruby

# frozen_string_literal: true
module Gitlab
module Metrics
module Samplers
class ThreadsSampler < BaseSampler
SAMPLING_INTERVAL_SECONDS = 5
KNOWN_PUMA_THREAD_NAMES = ['puma worker check pipe', 'puma server',
'puma threadpool reaper', 'puma threadpool trimmer',
'puma worker check pipe', 'puma stat payload'].freeze
SIDEKIQ_WORKER_THREAD_NAME = 'sidekiq_worker_thread'
METRIC_PREFIX = "gitlab_ruby_threads_"
METRIC_DESCRIPTIONS = {
max_expected_threads: "Maximum number of threads expected to be running and performing application work",
running_threads: "Number of running Ruby threads by name"
}.freeze
def metrics
@metrics ||= METRIC_DESCRIPTIONS.each_with_object({}) do |(name, description), result|
result[name] = ::Gitlab::Metrics.gauge(:"#{METRIC_PREFIX}#{name}", description)
end
end
def sample
metrics[:max_expected_threads].set({}, Gitlab::Runtime.max_threads)
threads_by_name.each do |name, threads|
uses_db, not_using_db = threads.partition { |thread| thread[:uses_db_connection] }
set_running_threads(name, uses_db_connection: "yes", size: uses_db.size)
set_running_threads(name, uses_db_connection: "no", size: not_using_db.size)
end
end
private
def set_running_threads(name, uses_db_connection:, size:)
metrics[:running_threads].set({ thread_name: name, uses_db_connection: uses_db_connection }, size)
end
def threads_by_name
Thread.list.group_by { |thread| name_for_thread(thread) }
end
def uses_db_connection(thread)
thread[:uses_db_connection] ? "yes" : "no"
end
def name_for_thread(thread)
thread_name = thread.name.to_s.presence
if thread_name.presence.nil?
'unnamed'
elsif thread_name =~ /puma threadpool \d+/
# These are the puma workers processing requests
'puma threadpool'
elsif use_thread_name?(thread_name)
thread_name
else
'unrecognized'
end
end
def use_thread_name?(thread_name)
thread_name == SIDEKIQ_WORKER_THREAD_NAME ||
# Samplers defined in `lib/gitlab/metrics/samplers`
thread_name.ends_with?('sampler') ||
# Exporters from `lib/gitlab/metrics/exporter`
thread_name.ends_with?('exporter') ||
KNOWN_PUMA_THREAD_NAMES.include?(thread_name)
end
end
end
end
end