https://lorbic.com/tags/redis/ Recent content in Redis on Lorbic Hugo en Tue, 07 Jul 2026 17:00:00 +0530 https://lorbic.com/designing-a-rate-limiter/ Tue, 07 Jul 2026 17:00:00 +0530 https://lorbic.com/designing-a-rate-limiter/ <p>There is a class of bugs that only happen at midnight.</p> <p>Your API has a rate limit: 1000 requests per minute. A client hits 999 at 11:59:59 PM, then fires another 999 at 12:00:00 AM. Two windows, two clean counters, all 1998 requests allowed. Your database gets a spike it was never designed to handle, and you spend the next hour wondering how your rate limiter let this through.</p> <p>It did let it through. You just did not know it.</p>