NAME¶

rrdruby - About the RRD Ruby bindings

SYNOPSIS¶

 require "RRD"
 RRD.create(
    rrd,
    "--step", "300",
    "DS:a:GAUGE:600:U:U",
    "DS:b:GAUGE:600:U:U",
    "RRA:AVERAGE:0.5:1:300")

DESCRIPTION¶

The rrdtool functions are directly callable via the Ruby programming language. This wrapper implementation has been written from the scratch (without SWIG)

The API simply expects string parameters to the functions. Please refer to the other rrdtool documentation for functions and valid arguments.

EXAMPLE¶

 $: << '/path/to/rrdtool/lib/ruby/1.8/i386-linux'
 require "RRD"
 name = "test"
 rrd = "#{name}.rrd"
 start = Time.now.to_i
 RRD.create(
    rrd,
    "--start", "#{start - 1}",
    "--step", "300",
        "DS:a:GAUGE:600:U:U",
    "DS:b:GAUGE:600:U:U",
    "RRA:AVERAGE:0.5:1:300")
 puts
 puts "updating #{rrd}"
 start.to_i.step(start.to_i + 300 * 300, 300) { |i|
    RRD.update(rrd, "#{i}:#{rand(100)}:#{Math.sin(i / 800) * 50 + 50}")
 }
 puts
 puts "fetching data from #{rrd}"
 (fstart, fend, data, step) = RRD.fetch(rrd, "--start", start.to_s, "--end",
      (start + 300 * 300).to_s, "AVERAGE")
 puts "got #{data.length} data points from #{fstart} to #{fend}"
 puts
 puts "generating graph #{name}.png"
 RRD.graph(
   "#{name}.png",
    "--title", " RubyRRD Demo",
    "--start", "#{start+3600}",
    "--end", "start + 1000 min",
    "--interlaced",
    "--imgformat", "PNG",
    "--width=450",
    "DEF:a=#{rrd}:a:AVERAGE",
    "DEF:b=#{rrd}:b:AVERAGE",
    "CDEF:line=TIME,2400,%,300,LT,a,UNKN,IF",
    "AREA:b#00b6e4:beta",
    "AREA:line#0022e9:alpha",
    "LINE3:line#ff0000")
 puts

If you use the --ruby-site-install configure option you can drop the $: line since the RRDtool module will be found automatically.

If RRDtool runs into trouble, it will throw an exception which you might want to catch.

SEE ALSO¶

rrdcreate, rrdupdate, rrdgraph, rrddump, rrdfetch, rrdtune, rrdlast, rrdxport, rrdinfo

AUTHOR¶

Loies Lherbier <lois.lherbier@covadis.ch>

Miles Egan <miles@caddr.com>