goxlag.rb

#!/usr/bin/ruby
# encoding: utf-8
# Created: 2013-03-30 11:49:19 +0200

# How often to check in seconds:
TIMEOUT = 10
# Alert when lag is greates then in seconds:
LAG_MAX = 0.05

STDOUT.sync = true
%w{
net/http
json
}.each { |r| require r}

def goxlag
  begin
    uri_raw = 'https://data.mtgox.com/api/1/generic/order/lag'
    uri = URI.parse uri_raw
    https = Net::HTTP.new uri.host, uri.port
    https.use_ssl = true
    request = Net::HTTP::Get.new uri.request_uri
    response = https.request request
    res =  JSON.parse response.body
    cur_lag = res["return"]['lag'].to_f
    if cur_lag >= LAG_MAX*1e6
      puts "ALERT"
    end
    puts "#{Time.now.to_s} lag: #{res["return"]["lag_secs"]} secs"
  rescue Exception => e
    puts "ERROR #{e.class} #{e.message}. Will retry"
  end
end

if __FILE__ == $0
  loop do
    goxlag
    sleep TIMEOUT
  end
end