gitlab-org--gitlab-foss/lib/gitlab/metrics/method_call.rb
2017-12-26 17:23:12 -02:00

94 lines
3 KiB
Ruby

# rubocop:disable Style/ClassVars
module Gitlab
module Metrics
# Class for tracking timing information about method calls
class MethodCall
@@measurement_enabled_cache = Concurrent::AtomicBoolean.new(false)
@@measurement_enabled_cache_expires_at = Concurrent::AtomicReference.new(Time.now.to_i)
MUTEX = Mutex.new
BASE_LABELS = { module: nil, method: nil }.freeze
attr_reader :real_time, :cpu_time, :call_count, :labels
def self.call_duration_histogram
return @call_duration_histogram if @call_duration_histogram
MUTEX.synchronize do
@call_duration_histogram ||= Gitlab::Metrics.histogram(
:gitlab_method_call_duration_seconds,
'Method calls real duration',
Transaction::BASE_LABELS.merge(BASE_LABELS),
[0.01, 0.05, 0.1, 0.5, 1])
end
end
def self.measurement_enabled_cache_expires_at
@@measurement_enabled_cache_expires_at
end
# name - The full name of the method (including namespace) such as
# `User#sign_in`.
#
def initialize(name, module_name, method_name, transaction)
@module_name = module_name
@method_name = method_name
@transaction = transaction
@name = name
@labels = { module: @module_name, method: @method_name }
@real_time = 0.0
@cpu_time = 0.0
@call_count = 0
end
# Measures the real and CPU execution time of the supplied block.
def measure
start_real = System.monotonic_time
start_cpu = System.cpu_time
retval = yield
real_time = System.monotonic_time - start_real
cpu_time = System.cpu_time - start_cpu
@real_time += real_time
@cpu_time += cpu_time
@call_count += 1
if call_measurement_enabled? && above_threshold?
self.class.call_duration_histogram.observe(@transaction.labels.merge(labels), real_time)
end
retval
end
# Returns a Metric instance of the current method call.
def to_metric
Metric.new(
Instrumentation.series,
{
duration: real_time.in_milliseconds.to_i,
cpu_duration: cpu_time.in_milliseconds.to_i,
call_count: call_count
},
method: @name
)
end
# Returns true if the total runtime of this method exceeds the method call
# threshold.
def above_threshold?
real_time.in_milliseconds >= Metrics.method_call_threshold
end
def call_measurement_enabled?
expires_at = @@measurement_enabled_cache_expires_at.value
if expires_at < Time.now.to_i
if @@measurement_enabled_cache_expires_at.compare_and_set(expires_at, 1.minute.from_now.to_i)
@@measurement_enabled_cache.value = Feature.get(:prometheus_metrics_method_instrumentation).enabled?
end
end
@@measurement_enabled_cache.value
end
end
end
end