How do I make sure my website is live all the time? [duplicate]

Question

Possible Duplicate:
Services to monitor and report if a web site goes down?

I've had an interesting day. I've been with a hosting company for 8+ years without a hitch. Today the MySQL on my server failed without any real reason. I had no idea so my site was down for 3 hours and of course I got emails from customers wondering what had happened. Not fun.

What are ways to ensure my site is always live? It would be great if I got a text message saying it's down. Are there any practical things that one should do to ensure their site is performing?

Answer 1

http://www.pingdom.com/ or http://newrelic.com are both really good services!

Answer 2

Have been using IP Sentry since it first came out on single server operations up to load balanced enterprise situations. Can't say enough good about it.

Answer 3

I use this Perl script to monitor all the services on my production server

#!/usr/bin/perl

use SendMail;
use IO::Socket;

#Find Server IP
$hostname="HostName";
my($addr)=inet_ntoa((gethostbyname($hostname))[4]);

@downservice = ();
@services = ( 'nginx', 'apache2', 'mysql' );
foreach my $service (@services) {
my $status = `/bin/ps cax | /bin/grep $service`;
if (!$status) {
     push (@downservice, $service);
 }
}

$sm = new SendMail("EmailServer");
$sm->setDebug($sm->OFF);
$sm->From("FromMailID");
$sm->Subject("Alert");
$sm->To("ToEmailID");
$sm->setMailBody("The Following Services are Down { @downservice } in Server $addr");

# Check if the mail sent successfully or not.
if ($sm->sendMail() != 0) {
  print $sm->{'error'}."\n";
  exit -1;
}
# Mail sent successfully.
print "Done\n\n";
exit 0;

The Script is added to the cron job and runs every 5 mins is a service is down it send's email alert