Graphing unicorn active/queued processes (via sockets)

unicorn-graphite.rb

#!/usr/bin/env ruby
require 'rubygems'
require 'raindrops'
require 'statsd'

#
#  This script monitors the active and queued unicorn processes.
#  It uses the raindrops gem to look at the unix domain socket.
#  Stats are polled every second (for one minute) and pushed to
#  statsd as a counter. This script runs once a minute.
#
#  There is one parameter: the location of the socket
#  
#  The stats are viewable on the Graphite paths:
#
#    stats.guages.rails.unicorns.[hostname].[app].[active,queued].[max,average]
#
#  Example: 
#
#    $ unicorn-graphite location-app
#


# Graphite Settings:

GRAPHITE_HOST  = "graphite"
GRAPHITE_PORT  = 8125

# ---

@app = ARGV[0]
@socket = "/var/nginx/#{@app}/unicorn.sock"
@host =`/bin/hostname -s`.chomp
@namespace = "rails.unicorns.#{@host}.#{@app.gsub('.','-')}"

@summary= {}

def update_totals(name, value)
  @summary[name] ||= {}
  @summary[name][:total] ||= 0
  @summary[name][:total] += value     

  @summary[name][:max] ||= 0
  @summary[name][:max] = value if (value > @summary[name][:max])
end

def send_stats(name)
  avg = @summary[name][:total]/60
  max = @summary[name][:max]
  statsd = Statsd.new(GRAPHITE_HOST, GRAPHITE_PORT)
  statsd.gauge("#{@namespace}.#{name}.average", avg)
  statsd.gauge("#{@namespace}.#{name}.max", max) 
  # puts "#{name} avg:#{avg} max:#{max}"
end

60.times do
  # raindrops returns an array of arrays, which is weird:
  stats = Raindrops::Linux.unix_listener_stats(@socket).first
  
  stats = stats[1]
  # puts "#{@host} - active: #{stats.active} queued: #{stats.queued}"

  update_totals(:active, stats.active)
  update_totals(:queued, stats.queued)

  sleep(1)
end

# send result to statsd
send_stats(:active) 
send_stats(:queued)