Nginx Proxy Cache for Managing HEAD Requests with proxy_cache_convert_head

Using the proxy_cache Module in Nginx

An important point to note is that Nginx is one of the most popular and widely used web servers, and its configuration has a significant impact on the performance and speed of websites. Considering that the next section will discuss the ngx_http_proxy_module and the proxy_cache_convert_head directive, we will actually focus on caching requests and managing responses. This directive helps to better manage the cache.

The ngx_http_proxy_module provides the ability to forward requests to another backend server and cache responses for future requests until the main server is reduced. One of the interesting features of this module, the proxy_cache_convert_head directive, allows us to manage HEAD requests more efficiently. By using this feature, Nginx can avoid repeatedly contacting the original server, retrieving responses from its own cache instead.

In many situations, users when submitting HEAD requests actually are seeking metadata or information about the resource in question. Therefore, if we choose to retrieve this request from our cache, we can speed up the response time significantly.

Let’s look at some sample code to better understand how this feature can be implemented within the Nginx configuration file. With a few lines of simple code, we can start optimizing our web server.

location / {
    proxy_pass http://backend;
    proxy_cache my_cache;
    proxy_cache_convert_head on;
}

Code Explanation

• location /: This line specifies that the configurations below will apply to requests for the root path of the website.


• proxy_pass http://backend;: With this line, requests are directed to the backend server.


• proxy_cache my_cache;: This directive specifies which cache to use for storing responses.


• proxy_cache_convert_head on;: By enabling this directive, HEAD requests can be managed more efficiently, allowing Nginx to retrieve responses from the cache instead of sending them back to the original server.