scgi_cache_methods
The `scgi_cache_methods` directive specifies the HTTP methods that should be cached when using the SCGI protocol with NGINX.
Description
The scgi_cache_methods directive is part of the caching configuration in an NGINX setup that utilizes the SCGI protocol, commonly used for interfacing with language-based web applications. By defining which HTTP methods (such as GET and POST) should be cached, this directive helps in optimizing cache usage, enhancing application performance, and reducing response times by serving cached responses for specified methods.
This directive accepts one or more HTTP methods as arguments. The default behavior is to cache responses only for the GET and HEAD methods, thereby ensuring that dynamic content is managed correctly. By extending this to include methods like POST, administrators can improve caching strategies for APIs or applications that utilize these methods, although caution must be taken as caching POST responses can lead to issues with stateful interactions. When setting up caching, it's crucial to balance caching ephemeral data against the performance benefits for smoother user experiences.
Contextually, the scgi_cache_methods directive can be utilized within the http, server, or location blocks to tailor caching behavior to specific areas of the application. Proper configuration requires a clear understanding of application data flow and the implications of caching various HTTP methods in the context of application logic.
Config Example
location /api {
scgi_pass 127.0.0.1:9000;
scgi_cache my_cache;
scgi_cache_methods GET POST;
}Caching POST responses can lead to unintended side effects since POST requests are generally used for data submission and should typically not be cached.
Ensure that your application logic correctly handles the cached responses to avoid stale or incorrect data being served to users.