What is the http cache status code?

HTTP cache status code refers to a set of status codes used to indicate the interaction between the client cache and the server cache in the HTTP protocol. It is used with the cache-Control, Expires and other caches in the request header and response header. Related fields are used together to tell the client how to handle the cache and how to update the cache. The use of cache status codes can improve the communication efficiency between the server and the client and reduce repeated requests and responses.

# Operating system for this tutorial: Windows 10 system, Dell G3 computer.

HTTP cache status code refers to a set of status codes used to indicate the interaction between client cache and server cache in the HTTP protocol. These status codes are used in conjunction with cache-related fields such as Cache-Control and Expires in the request header and response header to tell the client how to handle the cache and how to update the cache.

Common HTTP cache status codes include:

• 200 OK: The response returned by the server is cacheable and can be cached for next use. Caching can be used directly when making requests with the same URI.

• 304 Not Modified: Indicates that the client cache is still valid, the server does not return new content, and the client can get the response from the cache.

• 403 Forbidden: Indicates that the client does not have permission to access the resource and the server will not cache the response.

• 404 Not Found: Indicates that the requested resource was not found and the server will not cache the response.

• 410 Gone: Indicates that the requested resource has been permanently deleted and the server will not cache the response.

• 500 Internal Server Error: Indicates that an error occurred when the server processed the request. The client will send a new request to the server, that is, the cache will not be used.

• 502 Bad Gateway: It means that the server playing the role of gateway or proxy receives an invalid response from the upstream server, and the client will send a new request to the server, that is, no cache is used.

• 503 Service Unavailable: Indicates that the server is currently unable to process the request, and the client will send a new request to the server, that is, the cache will not be used.

The use of HTTP cache status codes can improve the communication efficiency between the server and the client and reduce repeated requests and responses. In practical applications, developers can configure relevant caching strategies according to specific needs and rationally use HTTP cache status codes to improve system performance and user experience.

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