A reverse proxy is a server or software application that acts as an intermediary between a client (usually a web browser or an application) and one or more backend servers (web servers or application servers). Unlike a regular proxy that operates on the client-side and forwards requests from clients to other servers, the reverse proxy receives requests from clients and forwards them to the appropriate backend servers.
The main functions of a reverse proxy are:
Load Balancing: The reverse proxy distributes incoming client requests across different backend servers to balance the workload and optimize the utilization of each server. This improves overall system scalability and performance.
Caching: A reverse proxy can cache frequently requested content, allowing it to serve the content directly to clients on subsequent requests. This reduces response time and lessens the load on the backend servers.
Security: The reverse proxy can act as an additional security layer, preventing direct access to backend servers and thereby enhancing security. It can also serve as a firewall to block malicious or unauthorized requests.
SSL Termination: A reverse proxy can decrypt the encryption (SSL/TLS) of incoming requests and forward the unencrypted traffic to the backend servers. This offloads the backend servers from the resource-intensive encryption and enables centralized SSL certificate management.
Load Balancing: By distributing requests to different backend servers, a reverse proxy can apply load balancing strategies to ensure an even distribution of load across all servers.
Reverse proxies are commonly used in complex web applications, content delivery networks (CDNs), e-commerce platforms, and high-availability environments to enhance the performance, scalability, and security of web applications.