HTTP caching proxy
Topics: HTTP caching
As an intermediary system between a HTTP server and a HTTP client, caching proxies speed up web delivery by storing each HTTP response until its cache expiry time (also called time-to-live, TTL) is reached. If a request URL matches content stored in the cache, the proxy immediately delivers this content in response. This reduces the volume of expensive content rendering on the backend HTTP server, lowering its load in the process.
Sequence of a cache miss where the proxy doesn’t have the requested content:
sequenceDiagram
participant Client
participant Proxy as Caching proxy
participant Server
Client->>Proxy: HTTP request
Proxy->>Server: Forward request
Server-->>Proxy: HTTP response
Proxy-->>Proxy: Store response
Proxy-->>Client: HTTP response
Sequence of a cache hit:
sequenceDiagram
participant Client
participant Proxy as Caching proxy
participant Server
Client->>Proxy: HTTP request
Proxy-->>Proxy: Retrieve cached response
Proxy-->>Client: HTTP response
The performance advantage is obvious.