graphite-redis : monitor redis statistics with graphite across several hosts

redis-graphite.sh

#!/usr/bin/env ruby
require 'socket'

# This script runs every minute, captures stats about redis
# and forwards them to graphite as counter values.

# Graphite/carbon settings
GRAPHITE_HOST="graphite.intra.local.ch"
GRAPHITE_PORT=8125

def instrument_redis(redis_host)
  namespace = "rails.redis.#{redis_host}"
  redis = {}
  `/usr/bin/redis-cli -h #{redis_host} info`.each_line do |line|
    key,value = line.chomp.split(/:/)
    redis[key]=value
  end
  %w{used_memory total_commands_processed
     total_connections_received keyspace_hits
     changes_since_last_save
     connected_clients keyspace_misses expired_keys}.each do |item|
     send_data("#{namespace}.#{item}", redis[item].to_i)
  end
  frag1000 = redis['mem_fragmentation_ratio'].to_f*1000;
  send_data("#{namespace}.mem_fragmentation_ratio", frag1000)
end

def send_data(path, value, time=nil)
  time ||= Time.new
  msg = "#{path}:#{value}|c\n"
  puts msg
  @socket.send(msg, 0, GRAPHITE_HOST, GRAPHITE_PORT)
  msg
end


# do stuff
@socket = UDPSocket.new
instrument_redis('rails-hw-snr01')
instrument_redis('rails-hw-snr02')
instrument_redis('rails-hw-inx01')
instrument_redis('rails-hw-inx02')
@socket.close