class NewRelic::Agent::Samplers::CpuSampler

Attributes

last_time[R]

Public Class Methods

new() click to toggle source
# File lib/new_relic/agent/samplers/cpu_sampler.rb, line 14
def initialize
  @last_time = nil
  @processor_count = NewRelic::Agent::SystemInfo.num_logical_processors
  if @processor_count.nil?
    NewRelic::Agent.logger.warn("Failed to determine processor count, assuming 1")
    @processor_count = 1
  end
  poll
end
supported_on_this_platform?() click to toggle source
# File lib/new_relic/agent/samplers/cpu_sampler.rb, line 40
def self.supported_on_this_platform?
  # Process.times on JRuby < 1.7.0 reports wall clock elapsed time,
  # not actual cpu time used, so this sampler can only be used on JRuby >= 1.7.0.
  if defined?(JRuby)
    return JRUBY_VERSION >= '1.7.0'
  end
  true
end

Public Instance Methods

poll() click to toggle source
# File lib/new_relic/agent/samplers/cpu_sampler.rb, line 49
def poll
  now = Time.now
  t = Process.times
  if @last_time
    elapsed = now - @last_time
    return if elapsed < 1 # Causing some kind of math underflow

    usertime = t.utime - @last_utime
    systemtime = t.stime - @last_stime

    record_systemtime(systemtime) if systemtime >= 0
    record_usertime(usertime) if usertime >= 0

    # Calculate the true utilization by taking cpu times and dividing by
    # elapsed time X processor_count.

    record_user_util(usertime / (elapsed * @processor_count))
    record_system_util(systemtime / (elapsed * @processor_count))
  end
  @last_utime = t.utime
  @last_stime = t.stime
  @last_time = now
end
record_system_util(value) click to toggle source
# File lib/new_relic/agent/samplers/cpu_sampler.rb, line 28
def record_system_util(value)
  NewRelic::Agent.record_metric("CPU/System/Utilization", value)
end
record_systemtime(value) click to toggle source
# File lib/new_relic/agent/samplers/cpu_sampler.rb, line 36
def record_systemtime(value)
  NewRelic::Agent.record_metric("CPU/System Time", value)
end
record_user_util(value) click to toggle source
# File lib/new_relic/agent/samplers/cpu_sampler.rb, line 24
def record_user_util(value)
  NewRelic::Agent.record_metric("CPU/User/Utilization", value)
end
record_usertime(value) click to toggle source
# File lib/new_relic/agent/samplers/cpu_sampler.rb, line 32
def record_usertime(value)
  NewRelic::Agent.record_metric("CPU/User Time", value)
end