gitlab-org--gitlab-foss/lib/gitlab/metrics/method_call.rb
Yorick Peterse be3b878443 Track method call times/counts as a single metric
Previously we'd create a separate Metric instance for every method call
that would exceed the method call threshold. This is problematic because
it doesn't provide us with information to accurately get the _total_
execution time of a particular method. For example, if the method
"Foo#bar" was called 4 times with a runtime of ~10 milliseconds we'd end
up with 4 different Metric instances. If we were to then get the
average/95th percentile/etc of the timings this would be roughly 10
milliseconds. However, the _actual_ total time spent in this method
would be around 40 milliseconds.

To solve this problem we now create a single Metric instance per method.
This Metric instance contains the _total_ real/CPU time and the call
count for every instrumented method.
2016-06-17 13:09:55 -04:00

52 lines
1.3 KiB
Ruby

module Gitlab
module Metrics
# Class for tracking timing information about method calls
class MethodCall
attr_reader :real_time, :cpu_time, :call_count
# name - The full name of the method (including namespace) such as
# `User#sign_in`.
#
# series - The series to use for storing the data.
def initialize(name, series)
@name = name
@series = series
@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 = Time.now
start_cpu = System.cpu_time
retval = yield
@real_time += (Time.now - start_real) * 1000.0
@cpu_time += System.cpu_time.to_f - start_cpu
@call_count += 1
retval
end
# Returns a Metric instance of the current method call.
def to_metric
Metric.new(
@series,
{
duration: real_time,
cpu_duration: cpu_time,
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 >= Metrics.method_call_threshold
end
end
end
end