サーバ上で稼働している各fluentdプロセスのCPU使用率をfluentdに投げるスクリプト

fluentd_pidstat.rb

#!/usr/bin/env ruby

# Send process cpu usage for each fluentd process to fluentd.
# Each fluentd must be exected with -c (config) option
# This script might be executed periodically by cron.

require 'set'
require 'optparse'
require 'fluent-logger'

PIDSTAT_INTERVAL=30

opts = {}
ARGV.options {|opt|
  opt.on('-h HOST', 'fluentd host'){|v| opts[:host] =  v }
  opt.on('-p PORT', 'fluentd port'){|v| opts[:port] =  v }
  opt.on('-t tag', 'fluentd tag'){|v| opts[:tag] =  v }
  opt.on('-i string', 'host identifier'){|v| opts[:hostid] =  v }
  opt.parse!
}

opts = { 
  :host => "localhost",
  :port => 24224,
  :tag => "fluentd.processcpu",
  :hostid => `hostname`.strip
}.merge(opts)

log = Fluent::Logger::FluentLogger.new(nil, :host=>opts[:host], :port=>opts[:port])

# list of fluentd process
fluentd_processes = `ps -C ruby -f | grep fluentd`

# get conf name (assumes fluentd is started with -c option)
fluentd_conf_names = Set.new
fluentd_processes.split("\n").each do |l|
  if /\W(\w+\.conf)/ =~ l
    fluentd_conf_names << $1
  end
end

# start pidstat process in background
pipes = []
fluentd_conf_names.each do |f|
  # get pid of latest process. (not fluentd supervisor, but actual engine process)
  pid = `pgrep -n -f #{f}`.chomp
  i, o = IO.pipe
  puts "pidstat -p #{pid} 1 1"
  Process.spawn("LANG=C pidstat -h -p #{pid} #{PIDSTAT_INTERVAL} 1", :out => o)
  pipes << {:name => f.gsub(/\.conf$/,""), :in => i, :out => o  }
end

Process.waitall
puts "Process finished"

# read result
pipes.each do |p|
  p[:out].close
  while l = p[:in].gets
    if /^\s+\d+\s/ =~ l
      # ["", "1438580253", "2778", "0.00", "0.00", "0.00", "0.00", "0", "ruby"] blank, timestamp, pid, %user, %system, %guest, %CPU, CPU, command
      pidstat_out = (l.split(/\s+/))
      puts l.split(/\s+/).to_s
      puts "#{p[:name]} " + pidstat_out[6]
      log.post(opts[:tag],{ "name" => p[:name], "pid" => pidstat_out[2], "percent_cpu" => pidstat_out[6].to_f , "hostname" => opts[:hostid]})
    end
  end
end