# Reverse Proxy ![](/files/-M9pzRNbQFe-jR7RAUCF) Reference: A reverse proxy is a web server that centralizes internal services and provides unified interfaces to the public. Requests from clients are forwarded to a server that can fulfill it before the reverse proxy returns the server's response to the client. Additional benefits include: * **Increased security** - Hide information about backend servers, blacklist IPs, limit number of connections per client * **Increased scalability and flexibility** - Clients only see the reverse proxy's IP, allowing you to scale servers or change their configuration * **SSL termination** - Decrypt incoming requests and encrypt server responses so backend servers do not have to perform these potentially expensive operations * Removes the need to install [X.509 certificates](https://en.wikipedia.org/wiki/X.509) on each server * **Compression** - Compress server responses * **Caching** - Return the response for cached requests * **Static content** - Serve static content directly * HTML/CSS/JS * Photos * Videos * Etc #### Load balancer vs reverse proxy * Deploying a load balancer is useful when you have multiple servers. Often, load balancers route traffic to a set of servers serving the same function. * Reverse proxies can be useful even with just one web server or application server, opening up the benefits described in the previous section. * Solutions such as NGINX and HAProxy can support both layer 7 reverse proxying and load balancing. #### Disadvantage(s): reverse proxy * Introducing a reverse proxy results in increased complexity. * A single reverse proxy is a single point of failure, configuring multiple reverse proxies (ie a [failover](https://en.wikipedia.org/wiki/Failover)) further increases complexity. #### Source(s) and further reading * [Reverse proxy vs load balancer](https://www.nginx.com/resources/glossary/reverse-proxy-vs-load-balancer/) * [NGINX architecture](https://www.nginx.com/blog/inside-nginx-how-we-designed-for-performance-scale/) * [HAProxy architecture guide](http://www.haproxy.org/download/1.2/doc/architecture.txt) * [Wikipedia](https://en.wikipedia.org/wiki/Reverse_proxy) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://liuzhenglaichn.gitbook.io/system-design/basics/proxy.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.