Best Reverse Proxy
8 Top Open Source Reverse Proxy Servers for Linux – Tecmint
A reverse proxy server is a type of proxy server that is deployed between clients and back-end/origin servers, for example, an HTTP server such as NGINX, Apache, etc.. or application servers written in Nodejs, Python, Java, Ruby, PHP, and many other programming languages.
It is a gateway or an intermediary server that takes a client request, passes it on to one or more back-end servers, and subsequently fetches the response from the server and delivers it back to the client, thus making it appear as if the content originated from the reverse proxy server itself.
Generally, a reverse proxy server is an internal-facing proxy used as a ‘front-end‘ to control and protect access to back-end servers on a private network: it is typically deployed behind the network firewall.
It helps back-end servers to achieve anonymity to enhance their security. In an IT infrastructure, a reverse proxy can also function as an application firewall, load balancer, TLS terminator, web accelerator (by caching static and dynamic content), and much more.
In this article, we will review the 8 top open-source reverse proxy servers you can use on a Linux system.
HAProxy (HAProxy, which stands for High Availability Proxy), a free, open-source, very fast, reliable, and top-notch load balancer and proxying software for TCP and HTTP-based applications, built for high availability.
HAProxy is an HTTP reverse-proxy, a TCP proxy and normalizer, an SSL/TLS terminator/initiator/offloader, a caching proxy, an HTTP compression offloader, a traffic regulator, a content-based switch, a FastCGI gateway, and more. It is also a protection against DDoS and service abuse.
It is powered by an event-driven, non-blocking engine that combines a very fast I/O layer with a priority-based, multi-threaded scheduler which enables it to easily deal with tens of thousands of concurrent connections. Notably, HAProxy uses the PROXY protocol to pass the client’s connection information to backend or origin servers so that an application gets all the relevant information.
Some of HAProxy’s basic features include proxying, SSL support, monitoring both server states and its own state, high availability, load balancing, stickiness(maintain a visitor on the same server even across various events), content switching, HTTP rewriting, and redirection, server protection, logging, statistics, and much more.
NGINX, a free, open-source, high-performance, and very popular HTTP server and reverse proxy. It also functions as an IMAP/POP3 proxy server. NGINX is well known for its high performance, stability, rich feature set, simple and flexible configuration, and low resource consumption (particularly small memory footprint).
Just like HAProxy, NGINX has an event-driven architecture so it has no problem dealing with tens of thousands of concurrent connections, as it uses HAProxy’s PROXY protocol.
NGINX supports accelerated reverse proxying with caching using the ngx__proxy_module module, which allows passing requests to another server over protocols other than HTTP, such as FastCGI, uwsgi, SCGI, and memcached.
Importantly, it supports load balancing and fault tolerance which are vital aspects of large-scale distributed computing systems. The ngx__upstream_module module allows for defining groups of backend servers to distribute the requests coming from clients. This makes your applications more robust, available and reliable, highly scalable, with response time and throughput. Additionally, concerning security, it supports SSL/TLS termination and so many other security features.
Useful articles on Nginx web server you might like to read:
How to Install Nginx Web Server on Ubuntu 20. 04
How to Install Nginx on CentOS 8
How to Enable NGINX Status Page
3. Varnish HTTP Cache
Varnish HTTP Cache (or Varnish Cache or simply Varnish) is a free, open-source, high-performance, and very popular caching reverse-proxy software better known as a web application accelerator, designed to improve HTTP performance using server-side caching.
It is deployed between a client and an HTTP web server or application server; every time a client requests for information or a resource from a web server, Varnish stores a copy of the information, so the next time the client requests for the same information, Varnish will serve it without sending a request to the webserver thus reducing the load on the server and in turn speeding up web content delivery.
Varnish uses a flexible configuration language know as the Varnish Configuration Language (VLC) which among other things enables system administrators to configure how incoming requests should be processed, what content should be served, and from where, and how the request or response should be altered, and much more.
The varnish is also extensible – it can be extended using Varnish Modules (VMODs) and users can write their custom modules or use community provided modules.
The main limitation of Varnish is its lack of support for SSL/TLS. The only way to enable HTTPS is to deploy an SSL/TLS terminator or offloader such as HAProxy or NGINX in front of it.
Træfɪk (pronounced Traffic) is a free, open-source, modern, and fast HTTP reverse proxy and load balancer for deploying micro-services that supports multiple load balancing algorithms. It can interface with various providers (or service discovery mechanisms or orchestration tools) such as Kubernates, Docker, Etcd, Rest API, Mesos/Marathon, Swarm, and Zookeper.
Its lovable feature is its ability to manage its configuration automatically and dynamically thus discovering the right configuration for your services. It does this by scanning your infrastructure to find relevant information and discovers which service serves which request from the external world. The providers tell Træfɪk where your applications or micro-services are located.
Træfɪk’s other features are supported for WebSockets, HTTP/2, and GRPC, and hot reloading (continuously updates its configuration without restarts), HTTPS using Let’s Encrypt certificates (wildcard certificate support), and exposes a REST API. It also keeps access logs, and it provides metrics (Rest, Prometheus, Datadog, Statsd, InfluxDB).
Also, Træfɪk ships with a simple HTML-based web user interface used to keep an eye on events. It also supports circuit breakers, retry requests, rate limiting, and basic authentication.
5. Apache Traffic Server
Formerly a commercial product owned by Yahoo which was later handed over to the Apache Foundation, Apache Traffic Server is a free, open-source, and fast caching forward and reverse-proxy server.
Traffic Server also works as a load balancer and can participate in flexible cache hierarchies. It is known to have handled over 400 TB a day of traffic at Yahoo.
It features a set of keep-alive, filtering, or anonymizing of content requests, and is extensible via an API that allows users to create custom plugins to modify HTTP headers, handle ESI requests, or design new cache algorithms.
6. Squid Proxy Server
Squid is a free, open-source, and well-known proxy server and Web cache daemon that supports various protocols such as HTTP, HTTPS, FTP, and more. It features a reverse proxy (d-accelerator) mode that caches incoming requests for outgoing data.
It supports rich traffic optimization options, access control, authorization, logging facilities, and much more.
A Pound is another free and open-source, lightweight reverse-proxy and load balancer and front-end for web servers. It is also an SSL terminator (that decrypts HTTPS requests from clients and sends them as plain HTTP to the back-end servers), an HTTP/HTTPS sanitizer(that verifies requests for correctness and accept only well-formed ones), and a fail-over server.
8. Apache HTTP Server
Last but not least, we have an Apache HTTP server (also known as HTTPD), the most popular web server on the globe. It can also be deployed and configured to act as a reverse proxy.
Additionally, you can also checkout Skipper, the new kid on the block. It is a free and open-source HTTP router and reverse proxy for service composition, including use cases like Kubernetes Ingress.
That’s all we had for you in this guide. For more information about each tool in this list, check out their respective websites. Do not forget to share your thoughts with us via the feedback form below.
What is a Reverse Proxy Server – Imperva
What is Reverse Proxy Server
A reverse proxy server is an intermediate connection point positioned at a network’s edge. It receives initial HTTP connection requests, acting like the actual endpoint.
Essentially your network’s traffic cop, the reverse proxy serves as a gateway between users and your application origin server. In so doing it handles all policy management and traffic routing.
A reverse proxy operates by:
Receiving a user connection request
Completing a TCP three-way handshake, terminating the initial connection
Connecting with the origin server and forwarding the original request
Reverse Proxy vs Forward Proxy
In contrast, a forward proxy server is also positioned at your network’s edge, but regulates outbound traffic according to preset policies in shared networks. Additionally, it disguises a client’s IP address and blocks malicious incoming traffic.
Forward proxies are typically used internally by large organizations, such as universities and enterprises, to:
Block employees from visiting certain websites
Monitor employee online activity
Block malicious traffic from reaching an origin server
Improve the user experience by caching external site content
How CDNs Use Reverse Proxies
Deployed at your network edge, content delivery networks (CDNs) use reverse proxy technology to handle incoming and outgoing traffic. Their benefits include:
Reverse proxies are placed in several geographically dispersed locations, where mirror versions of website pages are compressed and cached. This facilitates rapid content delivery based on client geolocation, helping to reduce page load times and improve your user experience.
Located in front of your backend servers, reverse proxies are ideally situated to scrub all incoming application traffic before it’s sent on to your backend servers.
DDoS mitigation – Incoming traffic is distributed among a mesh of reverse proxy servers during a DDoS attack to deflate its overall impact.
Web application security – Reverse proxies are an ideal location to place a web application firewall to weed out malicious packets—including bad bots and hacker requests.
When routing your incoming traffic through a reverse proxy server, connections are first terminated by the proxy and then reopened with the backend server. From your users’ perspective, their requests are resolved via the proxy IP.
As a result, your origin server’s IP address is masked. This makes it considerably more difficult for attackers to gain access and launch direct-to-IP denial of service attacks.
Because reverse proxy server are the gateway between users and your application’s origin server, they’re able to determine where to route individual HTTP sessions. For applications using multiple backend servers, this means the reverse proxy can efficiently distribute the load, thereby improving overall user experience and helping ensure high availability.
In the event that a server goes down, reverse proxies act as a failover solution, rerouting traffic to ensure continued site availability.
What is a reverse proxy? | Proxy servers explained | Cloudflare
What is a reverse proxy?
A reverse proxy is a server that sits in front of web servers and forwards client (e. g. web browser) requests to those web servers. Reverse proxies are typically implemented to help increase security, performance, and reliability. In order to better understand how a reverse proxy works and the benefits it can provide, let’s first define what a proxy server is.
What’s a proxy server?
A forward proxy, often called a proxy, proxy server, or web proxy, is a server that sits in front of a group of client machines. When those computers make requests to sites and services on the Internet, the proxy server intercepts those requests and then communicates with web servers on behalf of those clients, like a middleman.
For example, let’s name 3 computers involved in a typical forward proxy communication:
A: This is a user’s home computer
B: This is a forward proxy server
C: This is a website’s origin server (where the website data is stored)
In a standard Internet communication, computer A would reach out directly to computer C, with the client sending requests to the origin server and the origin server responding to the client. When a forward proxy is in place, A will instead send requests to B, which will then forward the request to C. C will then send a response to B, which will forward the response back to A.
Why would anyone add this extra middleman to their Internet activity? There are a few reasons one might want to use a forward proxy:
To avoid state or institutional browsing restrictions – Some governments, schools, and other organizations use firewalls to give their users access to a limited version of the Internet. A forward proxy can be used to get around these restrictions, as they let the user connect to the proxy rather than directly to the sites they are visiting.
To block access to certain content – Conversely, proxies can also be set up to block a group of users from accessing certain sites. For example, a school network might be configured to connect to the web through a proxy which enables content filtering rules, refusing to forward responses from Facebook and other social media sites.
To protect their identity online – In some cases, regular Internet users simply desire increased anonymity online, but in other cases, Internet users live in places where the government can impose serious consequences to political dissidents. Criticizing the government in a web forum or on social media can lead to fines or imprisonment for these users. If one of these dissidents uses a forward proxy to connect to a website where they post politically sensitive comments, the IP address used to post the comments will be harder to trace back to the dissident. Only the IP address of the proxy server will be visible.
How is a reverse proxy different?
A reverse proxy is a server that sits in front of one or more web servers, intercepting requests from clients. This is different from a forward proxy, where the proxy sits in front of the clients. With a reverse proxy, when clients send requests to the origin server of a website, those requests are intercepted at the network edge by the reverse proxy server. The reverse proxy server will then send requests to and receive responses from the origin server.
The difference between a forward and reverse proxy is subtle but important. A simplified way to sum it up would be to say that a forward proxy sits in front of a client and ensures that no origin server ever communicates directly with that specific client. On the other hand, a reverse proxy sits in front of an origin server and ensures that no client ever communicates directly with that origin server.
Once again, let’s illustrate by naming the computers involved:
D: Any number of users’ home computers
E: This is a reverse proxy server
F: One or more origin servers
Typically all requests from D would go directly to F, and F would send responses directly to D. With a reverse proxy, all requests from D will go directly to E, and E will send its requests to and receive responses from F. E will then pass along the appropriate responses to D.
Below we outline some of the benefits of a reverse proxy:
Load balancing – A popular website that gets millions of users every day may not be able to handle all of its incoming site traffic with a single origin server. Instead, the site can be distributed among a pool of different servers, all handling requests for the same site. In this case, a reverse proxy can provide a load balancing solution which will distribute the incoming traffic evenly among the different servers to prevent any single server from becoming overloaded. In the event that a server fails completely, other servers can step up to handle the traffic.
Protection from attacks – With a reverse proxy in place, a web site or service never needs to reveal the IP address of their origin server(s). This makes it much harder for attackers to leverage a targeted attack against them, such as a DDoS attack. Instead the attackers will only be able to target the reverse proxy, such as Cloudflare’s CDN, which will have tighter security and more resources to fend off a cyber attack.
Global Server Load Balancing (GSLB) – In this form of load balancing, a website can be distributed on several servers around the globe and the reverse proxy will send clients to the server that’s geographically closest to them. This decreases the distances that requests and responses need to travel, minimizing load times.
Caching – A reverse proxy can also cache content, resulting in faster performance. For example, if a user in Paris visits a reverse-proxied website with web servers in Los Angeles, the user might actually connect to a local reverse proxy server in Paris, which will then have to communicate with an origin server in L. A. The proxy server can then cache (or temporarily save) the response data. Subsequent Parisian users who browse the site will then get the locally cached version from the Parisian reverse proxy server, resulting in much faster performance.
SSL encryption – Encrypting and decrypting SSL (or TLS) communications for each client can be computationally expensive for an origin server. A reverse proxy can be configured to decrypt all incoming requests and encrypt all outgoing responses, freeing up valuable resources on the origin server.
How to implement a reverse proxy
Some companies build their own reverse proxies, but this requires intensive software and hardware engineering resources, as well as a significant investment in physical hardware. One of the easiest and most cost-effective ways to reap all the benefits of a reverse proxy is by signing up for a CDN service. For example, the Cloudflare CDN provides all the performance and security features listed above, as well as many others.
Frequently Asked Questions about best reverse proxy
What is the use of reverse proxy?
A reverse proxy server is an intermediate connection point positioned at a network’s edge. It receives initial HTTP connection requests, acting like the actual endpoint. Essentially your network’s traffic cop, the reverse proxy serves as a gateway between users and your application origin server.
Is reverse proxy good?
A reverse proxy protects web servers from attacks and can provide performance and reliability benefits.
Why Nginx is called reverse proxy?
nginx is a web server, similar to apache and IIS . Like many web servers it can be configured to work in forward proxy mode or reverse proxy mode. The phrase “nginx reverse proxy” means the nginx server configured as a reverse proxy.Feb 15, 2019