Send mail on MYSQL connection failure

Good idea to get notified on failures, but a couple of practical points will make alerts reliable and useful.

The one-liner die(mail(...)) is brittle: it halts execution and prints whatever mail() returns (usually 1 or nothing), and it assumes the server MTA is available. @GaryKing was right that an external monitor is the most reliable way to detect a fully down site. @senexom’s pointer toward PHP error handling is also relevant — centralizing error/exception handling gives you one place to log and notify.

Use explicit error handling for the DB connect, log the problem, then send an alert. Example using PDO with exceptions (safer and compatible with modern PHP):

<?php
$dsn = "mysql:host=$host;dbname=$db;charset=utf8mb4";
$options = [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION, PDO::ATTR_TIMEOUT => 5];
try {
    $pdo = new PDO($dsn, $user, $pass, $options);
} catch (PDOException $e) {
    $msg = "DB connect failed: " . $e->getMessage();
    error_log($msg); // persistent record
    mail($adminEmail, "DB connection failure", $msg, "From: monitor@yourdomain.com");
    exit(1);
}
?>

For detecting Apache/site outages, run checks from outside the host (a VPS, another trusted server, or a third-party service). A simple cron-friendly shell check:

#!/bin/sh
status=$(curl -s -o /dev/null -w "%{http_code}" "https://example.com/")
if [ "$status" -ne 200 ]; then
  echo "Site returned $status at $(date)" | mail -s "Site down" admin@domain.com
fi

Practical cautions: don’t spam yourself on flapping outages — implement rate limits or grouping, keep a timestamped outage log for counting failures, and prefer authenticated SMTP libraries (PHPMailer or similar) if your host’s mail() is unreliable. Note: the old mysql_* extension used in early threads was removed from PHP 7.0; use PDO or mysqli in modern code.