Uptime monitoring tools

Sometimes people cann't believe in their infrastructure. This can be easily understood because maintaining complex software integrates several pieces of information. Moreover, people sometimes hire bad IT solutions and as a result, <s>shit</s> accidents happen.

I have been using some tools to report me web server down time. Here we go:

<ul>
<li><a href="http://www.monitor.us/">monitor.us</a>: it is a powerful tool that provides several features. I am currently using it to monitor a specific term in a specific page. It's a free feature and it can check a website from 2 different countries</li>
<li><a href="https://www.pingdom.com/">Pingdom</a>: it looks like a full solution to analyse performance issues and downtime</li>
<li><a href="http://pingoou.com.br/">Pingoou</a>: this a Brazilian option. It offers up to 3 URLs in the free account and notifications via SMS, Campfire, Hipchat and email in the paid accounts</li>
<li><a href="http://www.siteuptime.com/">SiteUptime</a>: 1 monitor for free each 30 minutes. Actually is not the best deal</li>
<li><a href="http://www.uptimerobot.com/">UptimeRobot</a>: it monitors up to 50 websites for free</li>
</ul>

<h2>Building it own tool</h2>

You can alternatively build your own monitoring tool to check if a website is up or down. The concept is pretty simple: you can use your favorite language to create a script that loads a page and then you are able to check a specific string in the document. In the following example I used Ruby and Mechanize gem to request a status page.

gem 'mechanize', '2.7.2'
require 'mechanize'
require 'pony'

def sendmail(to, subject, body)
    Pony.mail({
      :to => to,
      :via => :smtp,
      :subject => subject,
      :body => body,
      :charset => 'UTF-8',
      :via_options => {
        :address => 'smtp.sendgrid.net',
            :port => '587',
            :domain => 'heroku.com',
            :user_name => ENV['SENDGRID_USERNAME'],
            :password => ENV['SENDGRID_PASSWORD'],
            :authentication => :plain,
            :enable_starttls_auto => true
      }
    })
end

mechanize = Mechanize.new{|a| a.ssl_version, a.verify_mode = 'SSLv3', OpenSSL::SSL::VERIFY_NONE}
page = mechanize.get('https://www.yourwebsite.com/mytesturl')

content = ""

if page.body.include?('refused')
    content = 'Error: Connection Refused'
end

if content
    puts content
    sendmail("email@domain.com", "Monitor", content)
end

In this case, I use Heroku to run this script. The emails are delivered by SendGrid, via Pony gem. There are no costs in the process.