module NewRelic::Agent::SystemInfo

Public Class Methods

bsd?() click to toggle source
# File lib/new_relic/agent/system_info.rb, line 26
def self.bsd?
  !!(ruby_os_identifier =~ /bsd/i)
end
clear_processor_info() click to toggle source
# File lib/new_relic/agent/system_info.rb, line 32
def self.clear_processor_info
  @processor_info = nil
end
darwin?() click to toggle source
# File lib/new_relic/agent/system_info.rb, line 18
def self.darwin?
  !!(ruby_os_identifier =~ /darwin/i)
end
docker_container_id() click to toggle source
# File lib/new_relic/agent/system_info.rb, line 152
def self.docker_container_id
  return unless ruby_os_identifier =~ /linux/

  cgroup_info = proc_try_read('/proc/self/cgroup')
  return unless cgroup_info

  parse_docker_container_id(cgroup_info)
end
get_processor_info() click to toggle source
# File lib/new_relic/agent/system_info.rb, line 36
def self.get_processor_info
  if @processor_info.nil?
    if darwin?
      @processor_info = {
        :num_physical_packages  => sysctl_value('hw.packages').to_i,
        :num_physical_cores     => sysctl_value('hw.physicalcpu_max').to_i,
        :num_logical_processors => sysctl_value('hw.logicalcpu_max').to_i
      }
      # in case those don't work, try backup values
      if @processor_info[:num_physical_cores] <= 0
        @processor_info[:num_physical_cores] = sysctl_value('hw.physicalcpu').to_i
      end
      if @processor_info[:num_logical_processors] <= 0
        @processor_info[:num_logical_processors] = sysctl_value('hw.logicalcpu').to_i
      end
      if @processor_info[:num_logical_processors] <= 0
        @processor_info[:num_logical_processors] = sysctl_value('hw.ncpu').to_i
      end

    elsif linux?
      cpuinfo = proc_try_read('/proc/cpuinfo')
      @processor_info = cpuinfo ? parse_cpuinfo(cpuinfo) : {}

    elsif bsd?
      @processor_info = {
        :num_physical_packages  => nil,
        :num_physical_cores     => nil,
        :num_logical_processors => sysctl_value('hw.ncpu').to_i
      }
    end

    # give nils for obviously wrong values
    @processor_info.keys.each do |key|
      value = @processor_info[key]
      if value.is_a?(Numeric) && value <= 0
        @processor_info[key] = nil
      end
    end
  end

  @processor_info
rescue
  {}
end
linux?() click to toggle source
# File lib/new_relic/agent/system_info.rb, line 22
def self.linux?
  !!(ruby_os_identifier =~ /linux/i)
end
num_logical_processors() click to toggle source
# File lib/new_relic/agent/system_info.rb, line 142
def self.num_logical_processors; get_processor_info[:num_logical_processors] end
num_physical_cores() click to toggle source
# File lib/new_relic/agent/system_info.rb, line 141
def self.num_physical_cores    ; get_processor_info[:num_physical_cores    ] end
num_physical_packages() click to toggle source
# File lib/new_relic/agent/system_info.rb, line 140
def self.num_physical_packages ; get_processor_info[:num_physical_packages ] end
os_version() click to toggle source
# File lib/new_relic/agent/system_info.rb, line 148
def self.os_version
  proc_try_read('/proc/version')
end
parse_cgroup_ids(cgroup_info) click to toggle source
# File lib/new_relic/agent/system_info.rb, line 193
def self.parse_cgroup_ids(cgroup_info)
  cgroup_ids = {}

  cgroup_info.split("\n").each do |line|
    parts = line.split(':')
    next unless parts.size == 3
    _, subsystems, cgroup_id = parts
    subsystems = subsystems.split(',')
    subsystems.each do |subsystem|
      cgroup_ids[subsystem] = cgroup_id
    end
  end

  cgroup_ids
end
parse_cpuinfo(cpuinfo) click to toggle source
# File lib/new_relic/agent/system_info.rb, line 86
def self.parse_cpuinfo(cpuinfo)
  # Build a hash of the form
  #   { [phys_id, core_id] => num_logical_processors_on_this_core }
  cores = Hash.new(0)
  phys_id = core_id = nil

  total_processors = 0

  cpuinfo.split("\n").map(&:strip).each do |line|
    case line
    when /^processor\s*:/
      cores[[phys_id, core_id]] += 1 if phys_id && core_id
      phys_id = core_id = nil # reset these values
      total_processors += 1
    when /^physical id\s*:(.*)/
      phys_id = $1.strip.to_i
    when /^core id\s*:(.*)/
      core_id = $1.strip.to_i
    end
  end
  cores[[phys_id, core_id]] += 1 if phys_id && core_id

  num_physical_packages  = cores.keys.map(&:first).uniq.size
  num_physical_cores     = cores.size
  num_logical_processors = cores.values.reduce(0,:+)

  if num_physical_cores == 0
    num_logical_processors = total_processors

    if total_processors == 0
      # Likely a malformed file.
      num_logical_processors = nil
    end

    if total_processors == 1
      # Some older, single-core processors might not list ids,
      # so we'll just mark them all 1.
      num_physical_packages = 1
      num_physical_cores    = 1
    else
      # We have no way of knowing how many packages or cores
      # we have, even though we know how many processors there are.
      num_physical_packages = nil
      num_physical_cores    = nil
    end
  end

  {
    :num_physical_packages  => num_physical_packages,
    :num_physical_cores     => num_physical_cores,
    :num_logical_processors => num_logical_processors
  }
end
parse_docker_container_id(cgroup_info) click to toggle source
# File lib/new_relic/agent/system_info.rb, line 161
def self.parse_docker_container_id(cgroup_info)
  cpu_cgroup = parse_cgroup_ids(cgroup_info)['cpu']
  return unless cpu_cgroup

  container_id = case cpu_cgroup
  # docker native driver w/out systemd (fs)
  when %r{^/docker/([0-9a-f]+)$}                      then $1
  # docker native driver with systemd
  when %r{^/system\.slice/docker-([0-9a-f]+)\.scope$} then $1
  # docker lxc driver
  when %r{^/lxc/([0-9a-f]+)$}                         then $1
  # not in any cgroup
  when '/'                                            then nil
  # in a cgroup, but we don't recognize its format
  when %r{docker}                                     then
    ::NewRelic::Agent.logger.debug("Cgroup indicates docker but container_id unrecognized: '#{cpu_cgroup}'")
    ::NewRelic::Agent.increment_metric "Supportability/utilization/docker/error"
    return
  else
    ::NewRelic::Agent.logger.debug("Ignoring unrecognized cgroup ID format: '#{cpu_cgroup}'")
    return
  end

  if container_id && container_id.size != 64
    ::NewRelic::Agent.logger.debug("Found docker container_id with invalid length: #{container_id}")
    ::NewRelic::Agent.increment_metric "Supportability/utilization/docker/error"
    nil
  else
    container_id
  end
end
parse_linux_meminfo_in_mib(meminfo) click to toggle source
# File lib/new_relic/agent/system_info.rb, line 245
def self.parse_linux_meminfo_in_mib(meminfo)
  if meminfo && mem_total = meminfo[/MemTotal:\s*(\d*)\skB/,1]
    (mem_total.to_i / 1024).to_i
  else
    ::NewRelic::Agent.logger.debug("Failed to parse MemTotal from /proc/meminfo: #{meminfo}")
    nil
  end
end
proc_try_read(path) click to toggle source

A File.read against /(proc|sysfs)/* can hang with some older Linuxes. See bugzilla.redhat.com/show_bug.cgi?id=604887, RUBY-736, and github.com/opscode/ohai/commit/518d56a6cb7d021b47ed3d691ecf7fba7f74a6a7 for details on why we do it this way.

# File lib/new_relic/agent/system_info.rb, line 213
def self.proc_try_read(path)
  return nil unless File.exist?(path)
  content = ''
  File.open(path) do |f|
    loop do
      begin
        content << f.read_nonblock(4096)
      rescue EOFError
        break
      rescue Errno::EWOULDBLOCK, Errno::EAGAIN
        content = nil
        break # don't select file handle, just give up
      end
    end
  end
  content
end
processor_arch() click to toggle source
# File lib/new_relic/agent/system_info.rb, line 144
def self.processor_arch
  RbConfig::CONFIG['target_cpu']
end
ram_in_mib() click to toggle source
# File lib/new_relic/agent/system_info.rb, line 231
def self.ram_in_mib
  if darwin?
    (sysctl_value('hw.memsize').to_i / (1024 ** 2)).to_i
  elsif linux?
    meminfo = proc_try_read('/proc/meminfo')
    parse_linux_meminfo_in_mib(meminfo)
  elsif bsd?
    (sysctl_value('hw.realmem').to_i / (1024 ** 2)).to_i
  else
    ::NewRelic::Agent.logger.debug("Unable to determine ram_in_mib for host os: #{ruby_os_identifier}")
    nil
  end
end
ruby_os_identifier() click to toggle source
# File lib/new_relic/agent/system_info.rb, line 14
def self.ruby_os_identifier
  RbConfig::CONFIG['target_os']
end
sysctl_value(name) click to toggle source
# File lib/new_relic/agent/system_info.rb, line 81
def self.sysctl_value(name)
  # make sure to redirect stderr so we don't spew if the name is unknown
  %x`sysctl -n #{name} 2>/dev/null`
end