Contents

# An example SignalProcessor that generates a graph of the last 60 reported
# SystemLoad signals.
#
# It's pretty naff - it doesn't do any sort of time bounding so I can't say 
# that the graph is of the last 60 minutes or anything, but it's certainly 
# possible to do so if you fancy recording the timestamp that came in with 
# the report.
#
# Remember, if you're doing any heavy lifting such as generating images do
# push that work off into another Thread to avoid blocking the current thread.
#
require 'rubygems'
require 'scruffy'

module Smoke
  class SystemLoadProcessor < Smoke::SignalProcessor
    def initialize(*args)
      super
      @load = []
      0.upto(59) do |n|
        @load[n] = [0, 0, 0]
      end

      # Generate a load graph every 60 seconds.
      Thread.new(@load) do |load|
        loop do
          begin
            graph = Scruffy::Graph.new(:title => "Load Average")
            graph.value_formatter = Scruffy::Formatters::Number.new(:precision => 2)
            graph.add(:area, ' 1min', load.collect { |sample| sample[0] }, :opacity => 0.5)
            graph.add(:area, ' 5min', load.collect { |sample| sample[1] }, :opacity => 0.5)
            graph.add(:area, '15min', load.collect { |sample| sample[2] }, :opacity => 0.5)
            graph.render(:min_value => 0, :max_value => 1.00, :width => 700, :as => 'PNG', :to => 'load_average.png')
            sleep 60
          rescue => e
            STDERR.puts e.message + ":\n\n" + e.backtrace.join("\n") + "\n\n"
          end
        end
      end
    end

    def process(signal)
      @load.shift
      load_averages = [
        signal["report"]["one_minute"],
        signal["report"]["five_minutes"],
        signal["report"]["fifteen_minutes"]
      ]
      @load.push load_averages
    end
  end
end

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
smoke-0.0.3	contrib/processors/smoke/system_load_processor.rb