Whenever you develop a Laravel-based application that makes it into production you’ll probably provide some kind of API. Either for internal usage or for the customer to consume. However you most likely want to install some kind of rate limiting mechanism to make sure nobody is overusing your API and thus risking to take down your hosting infrastructure.
A well-known mechanism to prevent APIs from being overloaded with requests (kind of DoS) is a rate limiting. You’ll define a maximum number of requests in a given amount of time and when a client hits that maximum your web server will answer with HTTP 429 Too Many Requests. This indicates the client that there is some kind of cooldown time it needs to wait until further requests will be processed.
Rate Limiting Middleware
Laravel provides a convenient throttle middleware that provides that kind of rate limiting. It even supports different limits based upon a model so you can limit the amount of requests based upon a dynamic parameter.
This is a pretty cool default functionality. However it comes with a downside you will experience in production: The request still hits your Laravel application before being denied due to an exceeded limit which means the request still generates load on your web-server.
Of course the impact isn’t as high as it normally would be but in fact the web-server needs to boot up the Laravel framework and the request will pass any middleware that is processed before the throttle middleware itself. This alone could cause some database queries to be executed before the check for the exceeded rate limit even happens.
Finally the request causes impact on your cache server (e.g. Redis). Laravel’s rate limiting middleware stores the client’s IP address alongside with the amount of requests in a given time period and performs a check on every request.