Class: Solanum::Source::Diskstats

Inherits:
Solanum::Source show all
Defined in:
lib/solanum/source/diskstats.rb

Constant Summary collapse

STAT_FILE = 
'/proc/diskstats'
FIELDS = 
%w{
  major minor name
  reads_completed reads_merged read_sectors read_time
  writes_completed writes_merged write_sectors write_time
  io_active io_time io_weighted_time
}

Instance Attribute Summary collapse

Attributes inherited from Solanum::Source

#attributes, #period, #type

Instance Method Summary collapse

Methods inherited from Solanum::Source

#next_run

Constructor Details

#initialize(opts) ⇒ Diskstats

Returns a new instance of Diskstats.



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# File 'lib/solanum/source/diskstats.rb', line 16

def initialize(opts)
  super(opts)
  @devices = opts['devices'] || []
  @detailed = opts['detailed'] || false
  @last = {}
end

Instance Attribute Details

#devices ⇒ Object (readonly)

Returns the value of attribute devices.



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# File 'lib/solanum/source/diskstats.rb', line 4

def devices
  @devices
end

Instance Method Details

#collect! ⇒ Object 



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# File 'lib/solanum/source/diskstats.rb', line 31

def collect!
  events = []

  File.readlines(STAT_FILE).each do |line|
    stats = parse_stats(line)
    device = stats['name']

    if @devices.include?(device) || (@devices.empty? && device =~ /^sd[a-z]$/)
      if @last[device]
        diff = Hash.new(0)
        FIELDS.drop(3).each do |field|
          diff[field] = stats[field] - @last[device][field]
        end
        prefix = "diskstats #{device}"

        # Reads

        events << {
          service: "#{prefix} read sectors",
          metric: diff['read_sectors'],
        }

        events << {
          service: "#{prefix} read time",
          metric: diff['read_time'],
        }

        if @detailed
          events << {
            service: "#{prefix} read completed",
            metric: diff['reads_completed'],
          }

          events << {
            service: "#{prefix} read merged",
            metric: diff['reads_merged'],
          }
        end

        # Writes

        events << {
          service: "#{prefix} write sectors",
          metric: diff['write_sectors'],
        }

        events << {
          service: "#{prefix} write time",
          metric: diff['write_time'],
        }

        if @detailed
          events << {
            service: "#{prefix} write completed",
            metric: diff['writes_completed'],
          }

          events << {
            service: "#{prefix} write merged",
            metric: diff['writes_merged'],
          }
        end

        # IO

        events << {
          service: "#{prefix} io active",
          metric: diff['io_active'],
        }

        events << {
          service: "#{prefix} io time",
          metric: diff['io_time'],
        }

        events << {
          service: "#{prefix} io weighted-time",
          metric: diff['io_weighted_time'],
        }
      end
      @last[device] = stats
    end
  end

  events
end

#parse_stats(line) ⇒ Object 



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# File 'lib/solanum/source/diskstats.rb', line 24

def parse_stats(line)
  columns = line.strip.split(/\s+/)
  columns = columns.take(3) + columns.drop(3).map(&:to_i)
  Hash[FIELDS.zip(columns)]
end