I run a website. Is there a UNIX/win32 program that can contact it every 5 minutes to see if it's down?

And then send an email?

From serverfault Alex

• You could use lynx, curl, wget. Check return code and use mail to send email. Put it in cron.

  Or use an existing monitoring package, such as Nagios.

  xeon : Or Zenoss as a monitoring package.

  Joe H. : nagios, big brother and other monitoring packages keep track of state -- so they won't mail you *every* time it's not up (everyone loves the 100 messages of '(x) service is down!' in the morning). Some can be configured so that a single fail isn't reason to start alerting, and there's a system of escalation so it might start w/ email, move to paging, then contact more people if the service stays down.

  J.Zimmerman : To really be useful the ZenOSS ZenPack to monitor a website requires a license. We are running ZenOSS core and are really missing that functionality. It was easier to monitor a website with Nagios and easier to build a custom plugin for Nagios. A simple notification shell script using bash/wget/grep/mailx should be adequate. If not look at Nagios.

  Jim B : If you are going to go the route of using monitoring software I'd recommend argent guardian. It's not free but unlike the free options you'll have it up and running in a few hours with whatever escalation schedule and notifications you like
  From alex

• You can write a simple Perl program that runs in a loop at 5 minute intervals.

  #!/usr/bin/perl
  
  use LWP::Simple qw(get);
  for (;;) {
   sleep 300;
   if ( get("http://URL GOES HERE") ) {
      print 'ok'; 
   } else {
      print 'error';
   }
  }
  

  OR

  #!/usr/bin/perl 
  use Net::Telnet; 
  $connection=Net::Telnet->new(Timeout => 5, Host => "www.example.com", Port=>80, Errmode => sub {&error;}); 
  sub error { 
  print "Connection Failed!\n"; 
  } 
  

  Evan Carroll : Telneting to port 80 doesn't establish the website is up, it only establishes something is accepting connections on port 80.

  djangofan : no, but you an add to the script to get the http headers from the telnet request...
  From djangofan

• If it's important enough to send email, you may want to be able to customize your monitoring and alerts.

  I would recommend trying one of the following free packages:
  Zenoss - VMWare appliance
  Nagios - VMWare appliance
  Munin

  From hurfdurf

• I put the following in my crontab, and every 15 minutes if checks my web site, and if it's down I get an email.

  */15 * * * * if ! wget -q --spider http://www.rochesterflyingclub.com/ >/dev/null 2>&1; then echo "Rochester Flying Club site is down" ; fi
  

  From Paul Tomblin

• Well, if you don't want to do by yourself, you can try a free online tool to do that:

  http://sucuri.net

  It not only checks if your site is available, but if it has been changed, blacklisted, IPs changed, etc.

  From sucuri

• http://www.pingdom.com/ is free for a single web site.

  Uptime and response time with graphs, notifications, iPhone app, etc.

  From astrostl

• Could do this with a bash one liner:

  #!/usr/bin/bash
  while `sleep $((60*5))`;
    wget -nv http://not.com/exist.html 2>&1 |
      grep -C1 ERROR &&
      mailx -s "WEBSITE ERROR" "user@host.com"
    ;
    done ;
  

  Nagios is a great suggestion if you find yourself needing more information /like/ this (graphs, long term logs, easy reports) - I'd find it total overkill to get this job done though.

  David Mackintosh : Lot of line breaks in that one-liner.

  Evan Carroll : the top is a loop the one liner is : `wget -nv http://not.com/exist.html 2>&1 | grep -C1 ERROR && mailx -s "WEBSITE ERROR" "user@host.com" ;` Of course, you could fold the loop too, but that would but that would be cheating. The point is, such a tiny task is easily done.
  From Evan Carroll

• Nagios http://nagios.org/ is what you need. It's a bit of software that monitors things. It can do what you want and much much more.

  From Rory McCann

• We use nagios (actually Groundwork) to do this exact thing. You can use the basic http and https checks to see if the web server responds to an IP or a domain name. If you want to make sure that the website is running and displaying valid content you need to go a little further. We use the http_content plugin to check that specific content is displaying.

  From Craig