Using laravel Middleware too many MySQL connections are opened at the same time

You’re getting:

SQLSTATE[HY000] [1040] Too many connections

This happens when too many MySQL connections are opened at the same time (heavy traffic, bots, infinite loops, slow queries, or duplicate requests).
Yes—duplicate emails are a separate data issue, but they don’t directly cause “too many connections”. Still, you should clean duplicates + enforce unique, and also add rate limiting to stop bots/hits.

Below are both parts: (A) SQL to remove duplicate emails, (B) full Laravel code for rate limiting + practical DB connection fixes.

ERROR

SOLUTION

USING SQL
USING RATE LIMITING
[read blog first for middleware concept (https://www.debug.school/rakeshdevcotocus_468/implementing-canonical-url-redirects-using-laravel-middleware-3i9e)

SQL: Find duplicate emails and delete extra rows (keep 1)
See which emails are duplicated

SELECT email, COUNT(*) AS total
FROM users
WHERE email IS NOT NULL AND email <> ''
GROUP BY email
HAVING COUNT(*) > 1
ORDER BY total DESC;

Delete duplicates and keep the lowest id per email (SAFE METHOD)

(Make a backup first.)

DELETE u1
FROM users u1
JOIN users u2
  ON u1.email = u2.email
 AND u1.id > u2.id
WHERE u1.email IS NOT NULL AND u1.email <> '';

This keeps the smallest id row for each email and deletes the rest.
Add unique index so it never happens again

If you want email to be unique:

ALTER TABLE users
ADD UNIQUE KEY users_email_unique (email);

If this fails, it means duplicates still exist. Run step 2 again and re-check.

ANOTHER SOLUTION

[read blog first for middleware concept (https://www.debug.school/rakeshdevcotocus_468/implementing-canonical-url-redirects-using-laravel-middleware-3i9e)

Full Laravel code: Rate limiting (Web + API + Login)

1) Create a middleware for web routes (blocks bots fast)

Create file:

app/Http/Middleware/RateLimitWeb.php

<?php

namespace App\Http\Middleware;

use Closure;
use Illuminate\Http\Request;
use Symfony\Component\HttpFoundation\Response;
use Illuminate\Support\Facades\RateLimiter;

class RateLimitWeb
{
    public function handle(Request $request, Closure $next): Response
    {
        // Key: IP + path (so bot can't hammer same URL)
        $key = 'web:' . $request->ip() . ':' . sha1($request->path());

        // Allow 60 requests per minute per IP per page
        if (RateLimiter::tooManyAttempts($key, 60)) {
            $retryAfter = RateLimiter::availableIn($key);

            return response()->json([
                'message' => 'Too many requests. Please try again later.',
                'retry_after_seconds' => $retryAfter,
            ], 429);
        }

        RateLimiter::hit($key, 60);

        return $next($request);
    }
}

app/Http/Kernel.php

protected $routeMiddleware = [
    // ...
    'rate.web' => \App\Http\Middleware\RateLimitWeb::class,
];

Debug School

Using laravel Middleware too many MySQL connections are opened at the same time

ERROR

SOLUTION

ANOTHER SOLUTION

Full Laravel code: Rate limiting (Web + API + Login)

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