newrelic_redis_agent

#! /usr/bin/env ruby

require "rubygems"
require "bundler/setup"
require "dante"
require "newrelic_plugin"
require "redis"

pid_path = File.expand_path("../run/newrelic_redis_agent.pid", __FILE__)
log_path = File.expand_path("../log/newrelic_redis_agent.log", __FILE__)

runner = Dante::Runner.new('newrelic_redis_agent', :pid_path  => pid_path, :log_path => log_path)
runner.description = 'New Relic plugin agent for Redis'
runner.with_options do |opts|
  opts.on('-c', '--config FILE', String, 'Specify configuration file') do |config|
    options[:config_path] = config
  end
end

runner.execute do |opts|
  $redisplugin_config_path = opts[:config_path]

  module RedisAgent

    class Agent < NewRelic::Plugin::Agent::Base

      agent_guid "net.kenjij.newrelic_redis_plugin"
      agent_version "1.0.1"
      agent_config_options :instance_name, :url, :database
      agent_human_labels('Redis') do
        if instance_name == nil
          host = Socket.gethostname().sub(/\..*/, '')
          uri = URI.parse("#{url}")
          "#{host}:#{uri.port}"
        else
          "#{instance_name}"
        end
      end

      def setup_metrics
        @redis = Redis.new(:url => url)
        @last_values = {}
        @redis_info = nil
      end

      def poll_cycle
        begin
          @redis_info = @redis.info
          info = @redis_info
        rescue Exception => e
          puts e.message
          return nil
        end
        report_metric "Memory/Used", "bytes", info['used_memory'].to_i
        report_metric "Memory/RSS", "bytes", info['used_memory_rss'].to_i
        report_metric "Memory/Lua", "bytes", info['used_memory_lua'].to_i
        report_metric "Memory/Peak", "bytes", info['used_memory_peak'].to_i
        report_metric "CPU/System", "seconds", info['used_cpu_sys'].to_i
        report_metric "CPU/User", "seconds", info['used_cpu_sys'].to_i
        report_metric "CPU/Child System", "seconds", info['used_cpu_sys_children'].to_i
        report_metric "CPU/Child User", "seconds", info['used_cpu_sys_children'].to_i
        report_metric "RDB Unsaved Changes", "changes", info['rdb_changes_since_last_save'].to_i
        report_metric "RDB Save Time", "seconds", info['rdb_last_bgsave_time_sec'].to_i
        report_metric "Connection/Clients", "connections", info['connected_clients'].to_i
        report_metric "Connection/Slaves", "connections", info['connected_slaves'].to_i
        report_metric "ConnectionRate/Received", "connections", last_metric('total_connections_received')
        report_metric "ConnectionRate/Rejected", "connections", last_metric('rejected_connections')
        report_metric "Commands Processed", "commands", last_metric('total_commands_processed')
        report_metric "KeyspaceRate/Hits", "keys", last_metric('keyspace_hits')
        report_metric "KeyspaceRate/Misses", "keys", last_metric('keyspace_misses')
        report_metric "Expired Keys", "keys", last_metric('expired_keys')
        report_metric "Evicted Keys", "keys", last_metric('evicted_keys')
        dbstat = info[database] if database
        if dbstat
          begin
            h = Hash[dbstat.split(/,/).each.collect{|s|s.split('=')}]
            report_metric "Database/Total Keys", "keys", h['keys'].to_i
            report_metric "Database/Expiring Keys", "keys", h['expires'].to_i
          rescue Exception => e
            puts e.message
          end
        end
        @redis_info = nil
      end

      private

      def last_metric(key)
        return nil if @redis_info.nil? || @redis_info[key].nil?
        current_value = @redis_info[key].to_i
        if @last_values[key].nil?
          metric = 0
        else
          metric = current_value - @last_values[key]
          metric = 0 if metric < 0
        end
        @last_values[key] = current_value
        return metric
      end

    end

    if $redisplugin_config_path
      NewRelic::Plugin::Config.config_file = $redisplugin_config_path
    end
    NewRelic::Plugin::Setup.install_agent :redis, RedisAgent
    NewRelic::Plugin::Run.setup_and_run

  end

end