rails_rrdtool – Rails RRDTool Interface

What is it

rails_rrdtool is a Ruby on Rails plugin that provides a ruby-like interface to the RRD program. All variables and hashes sent to the tool are shell escaped so there is no worry about bad input. This is what Servly uses to manipulate RRDs.

Where is it

You can view / download / fork the source over @ GitHub.com
http://github.com/bluescripts/rails_rrdtool/tree/master

How To Install:

script/plugin install git://github.com/bluescripts/rails_rrdtool.git

Put these in your application_controller.rb file and adjust accordingly to your environment:

def rrd_tool
    if RAILS_ENV=="development"
      return "/opt/local/bin/rrdtool"
    else
      return "rrdtool"
    end
  end
 
  def rrd_path
      return  Dir.pwd &lt;&lt; "/rrd/"
  end
 
  def rrd_image_path
      return  Dir.pwd &lt;&lt; "/public/rrd/"
  end
 
  def rrd_image_url
    if RAILS_ENV=="development"
      return "/rrd/"
    else
      return "/rrd/"
    end
   end

How To Use:

Creating a RRD

#this example is taken from Servly
# see source for more possibilities of options
cpu_hash = {:step =&gt; 300, :heartbeat =&gt; 600,
                            :ds =&gt; [  {:name =&gt; "used", :type =&gt; "GAUGE"}, {:name =&gt; "idle", :type =&gt; "GAUGE"} ]  ,
                            :xff =&gt; ".5",
                            :rra =&gt; [ {:type =&gt; "AVERAGE", :steps =&gt; 1, :rows =&gt; 10080},
                                      {:type =&gt; "MAX", :steps =&gt; 60, :rows =&gt; 1},
                                      {:type =&gt; "MAX", :steps =&gt; 180, :rows =&gt; 1},
                                      {:type =&gt; "MAX", :steps =&gt; 360, :rows =&gt; 1},
                                      {:type =&gt; "MAX", :steps =&gt; 720, :rows =&gt; 1},
                                      {:type =&gt; "MAX", :steps =&gt; 1440, :rows =&gt; 1},
                                      {:type =&gt; "MAX", :steps =&gt; 2880, :rows =&gt; 1},
                                      {:type =&gt; "MAX", :steps =&gt; 4320, :rows =&gt; 1},
                                      {:type =&gt; "MAX", :steps =&gt; 10080, :rows =&gt; 1}
                                     ]
                            }
       RRD.create("#{rrd_path}file_name.rrd", cpu_hash , "#{rrd_tool}")

Updating a RRD

RRD.update("#{rrd_path}file_name.rrd", [VALUE_1, VALUE_2], "#{rrd_tool}") # as many values as the RRD has

Graphing a RRD

#example from Servly
# again see source for all possibilities
hash = {:ago =&gt; Time.now.advance(:hours =&gt; -12),
                :width =&gt; 420, :height =&gt; 60, :image_type =&gt; "PNG",
                :title =&gt; "CPU 12 Hour",
                :defs =&gt; [
                        {:key =&gt; "used", :type =&gt; "AVERAGE", :rpn =&gt; "AREA",
                         :color =&gt; "2275A0", :title =&gt; "CPU Usage" }
                          ],
                :lowerlimit =&gt; 0, :upperlimit =&gt; 100,
                :color =&gt; [
                        {:type =&gt; "GRID", :color =&gt; "000818"},
                        {:type =&gt; "FONT", :color =&gt; "111111"}
                          ]
                }
    @cmd = RRD.graph("#{rrd_path}file_name.rrd","#{rrd_image_path}file_name_cpu.png", hash, "#{rrd_tool}")