Class: Batsd::Handler::Gauge

Inherits:
Batsd::Handler show all
Defined in:
lib/batsd/handlers/gauge.rb

Overview

Handles gauge measurements ("|g")

Gauge measurements are never aggregated, and are only stored on disk. They are written to disk immediately upon receipt and without manipulation beyond correcting for sample rate (or more accurately, scale), if provided.

Instance Method Summary (collapse)

Methods inherited from Batsd::Handler

#statistics, #threadpool

Constructor Details

- (Gauge) initialize(options)

Set up a new handler to handle gauges

  • Set up a redis client

  • Set up a diskstore client to write aggregates to disk



17
18
19
20
21
 
# File 'lib/batsd/handlers/gauge.rb', line 17

def initialize(options)
  @redis = Batsd::Redis.new(options)
  @diskstore = Batsd::Diskstore.new(options[:root])
  super
end

Instance Method Details

- (Object) handle(key, value, sample_rate)

Process an incoming gauge measurement

  • Normalize for sample rate provided

  • Write current timestamp and value to disk

  • Store the name of the datapoint in Redis



29
30
31
32
33
34
35
36
37
38
39
40
 
# File 'lib/batsd/handlers/gauge.rb', line 29

def handle(key, value, sample_rate)
  @threadpool.queue Time.now.to_i, key, value, sample_rate do |timestamp, key, value, sample_rate|
    puts "Received #{key} #{value} #{sample_rate}" if ENV["VVERBOSE"]
    if sample_rate
      value = value.to_f / sample_rate.gsub("@", "").to_f
    end
    value = "#{timestamp} #{value}"
    key   = "gauges:#{key}"
    @diskstore.append_value_to_file(@diskstore.build_filename(key), value)
    @redis.add_datapoint key
  end
end