Rate Limiting Your Serverless Applications

Serverless applications, known for their scalability, can face challenges such as financial and technical costs, which necessitate implementing rate limiting mechanisms to manage traffic spikes and control resources effectively. Rate limiting is crucial for protecting resources, managing user quotas, and controlling costs, especially in scenarios involving public APIs where traffic spikes could degrade service quality or cause outages. Three main rate limiting solutions include setting a concurrency level for function executions, applying rate limiting on API Gateways, and using Redis for a comprehensive and customizable approach. Rate limiting at the concurrency level is easy to configure but only limits concurrency, not execution frequency. API Gateway-based rate limiting is also straightforward but limited to API Gateway users and lacks advanced features like quotas per user or IP. Redis offers a powerful and scalable solution with a rich ecosystem of open-source libraries, allowing for customized implementations, although it introduces some overhead. Rate limiting libraries simplify integrating these solutions into application code, demonstrating the practicality of implementing such systems in serverless environments.