What Is a Reverse Proxy? [All You Need To Know]

A reverse proxy is a server that acts as a middleman between clients and web servers. Its primary duty is to manage incoming client requests and direct them to their corresponding backend servers.

The level of control provided by reverse proxies significantly enhances the overall website performance and security. In fact, more than 25 million currently operational websites use reverse proxies.

By the end of this article, you’ll learn the significance of a reverse proxy and how it operates. Delve deeper into this dynamic technology to unveil the factors contributing to its widespread usage among websites.

Understanding How A Reverse Proxy Works

Client-server communication is crucial in web applications. However, direct communication between clients and servers may pose some risks to data security for both parties.

Malicious users can attempt to exploit vulnerabilities in the server’s code or infrastructure, leading to security breaches. In 2022, the average total cost of a data breach reached a record-breaking amount of $4.35 million.

An intermediary layer between clients and servers offers a safe and regulated path for communication, making a reverse proxy a suitable choice for this task.

Every time a client sends a request to a website, the request is forwarded to the reverse proxy instead of going directly to the servers. Then, the reverse proxy will make its request to the appropriate server.

Having gained insight into how reverse proxy works, it’s time to explore their real-world applications. In the following segment, you’ll learn about the common uses of reverse proxies.

Common Uses of a  Reverse Proxy

Handling requests on behalf of the servers is just one of the many uses of a reverse proxy. Its strategic positioning enables many benefits, from load balancing to facilitating A/B testing.

Discover each of them below:

Load Balancing

One of the most important functions of a reverse proxy is load balancing. It ensures that the load is equally distributed among all servers to avoid overloading.

Reverse proxies use various algorithms in load balancing, such as:

• Round Robin
• Sticky Round Robin
• Weighted Round Robin
• IP/URL Hash
• Least Connection
• Least Time

By distributing client requests across multiple backend servers, load balancing improves overall system performance, scalability, and fault tolerance.

Caching

Caching is a technique used in computer systems to store and reuse frequently accessed data. It improves system performance by providing quicker access to data, as the stored or cached copy can be retrieved more rapidly.

Reverse proxies enhance caching efficiency by storing and delivering frequently requested resources directly to clients. This relieves backend servers and accelerates content delivery.

Content Delivery Network

CDN extends the capabilities of caching even further. Reverse proxies can deliver content from edge servers closer to the clients, reducing latency.

Say a web server gets several requests from users all over the world. The requested asset is then pulled from that web server.

However, before returning the asset to the user, it is cached on the nearest edge server. If the same user asks for the same asset again, that edge server sends the response.

Security

Hackers typically perform malicious attacks by altering requests sent to a web server. However, an attacker cannot directly access the website's internal servers with a reverse proxy.

The reverse proxy can also identify the attacking user's IP address and deny them access to the server. As a result, it becomes more difficult for cybercriminals to launch an attack. 

Here are some common web-based attacks that a reverse proxy server can prevent:

• Distributed Denial-of-Service (DDoS) Attack
• SQL Injection
• Cross-Site Scripting (XSS) Attack

SSL/TLS Termination

Data transported over the Internet is encrypted using Transport Layer Security (TLS), an improved version of Secure Socket Layer (SSL). By doing this, you can prevent hackers from viewing your data. 

This is especially helpful for the following:

• passwords
• credit card details
• personal interactions

As a result, every data that reaches the origin server is encrypted. However, encrypting and decrypting communications for each client can be expensive for an origin server. This is when a tool like reverse proxy comes in helpful.

SSL/TLS termination can be handled by reverse proxies, allowing them to offload backend servers' resource-intensive encryption and decryption procedure. 

This approach increases overall system performance, particularly in cases with many secure connections.

A/B Testing

A/B testing, sometimes called split testing or bucket testing, analyzes two versions of a website or app’s landing page to evaluate which performs better.

A website or app screen is modified to produce a second version of the same page to do the test. Changes might range from a single headline or button to a complete website overhaul.

This helps companies determine which designs are most successful at turning site visitors into paying clients.

A reverse proxy is essential for supporting A/B testing since it statistically randomizes traffic to the various versions. The reverse proxy will continue employing the previously selected version whenever the user's browser makes future requests.

Advantages of Reverse Proxy

Reverse proxies offer a range of advantages that significantly enhance the performance, security, and web applications' scalability. 

From load balancing to security features, reverse proxies provide a comprehensive solution for optimizing and protecting modern web architectures.

It can offer a range of advantages by leveraging the power of reverse proxies. Organizations can improve the user experience, achieve high availability, and ensure the smooth operation of their web applications.

Improved Performance

A web application’s performance can be significantly improved by: 

• Caching
• Data compression
• Network Traffic Optimization

In addition to enhancing a website's efficiency, reverse proxies help decrease latency and network congestion.

Application Layer Routing

Regarding guiding website traffic, application layer routing encompasses the strategic determination of how data packets should be directed for intelligent traffic management. Reverse proxies excel in this area.

Requests can be routed to the most suitable backend server by employing reverse proxies, and the workload may be distributed more effectively.

Scalability and High Availability

Horizontal scalability, also known as scaling out, refers to the ability of a system to handle increased workload and demand by adding more servers.

However, achieving effective horizontal scalability may require designing the application architecture with distribution. Thankfully, reverse proxies can help meet these needs since it can distribute incoming traffic among multiple backend servers.

On top of that, reverse proxies ensure high availability configurations by providing failover mechanisms when a backend server becomes unavailable.

Content Filtering

Reverse proxies may function as content filters by analyzing requests. They provide content constraints and rewriting capabilities, enabling clients and backend servers to exert precise control over the data flow. 

This feature is useful in enforcing security policies and compliance requirements.

IP Address Preservation

In certain cases, apps use the client's IP address for geolocation, analytics, and implementing access limits based on IP.

Fortunately, with a reverse proxy in place, a client's IP address is kept intact and sent to the backend servers.

Granular Access Control

One important security aspect is granular access control, which is finely managing user permissions in systems and apps. Reverse proxies simplify this by enforcing specific policies for protected resources. 

This way, only those granted permission can access sensitive information or carry out certain tasks.

Bandwidth Optimization

Verse proxies decrease bandwidth consumption by compressing content before delivering it to clients. This feature leads to faster page load times, lower bandwidth costs, and a better user experience.

Disadvantages of Reverse Proxy

There are many advantages to using reverse proxies.  They do, however, have drawbacks that organizations should consider.

Understanding these drawbacks can aid organizations in making informed decisions when integrating reverse proxies into their systems.

Increased Latency

The reverse proxy is an additional layer between the client and the server. Unfortunately, this process can introduce latency whenever a client requests data. 

High latency can potentially slow down the overall response time of a website, affecting user experience.

Single Point of Failure

Using a reverse proxy introduces a single point of failure in the infrastructure. If the reverse proxy server fails or becomes overloaded, it might disrupt the entire system, resulting in downtime and service interruptions.

Careful planning and configuration of failover systems is essential to mitigate this risk.

Configuration Complexity

Organizations with several diverse backend servers may find it extremely challenging to set up and configure a reverse proxy.

Proper configuration requires a thorough understanding of the proxy server software and the backend applications it interacts with. 

It’s important to note that inadequate configuration can result in routing errors, security vulnerabilities, and performance issues.

SSL Certificate Challenges

Handling SSL certificates for multiple domains and subdomains can be challenging using a reverse proxy. 

Managing and renewing SSL certificates for each domain can become cumbersome, particularly in large-scale deployments.

At the same time, improper management of SSL certificates can lead to security vulnerabilities and may affect the availability of a website’s services.

Caching Challenges

As mentioned earlier, reverse proxies incorporate caching mechanisms to improve performance. However, caching dynamic or personalized content can be problematic. 

Deleting and updating the cache can be challenging for websites with dynamic content, which is constantly updated or tailored to the user.

Performance Overhead

Processing time is increased when a proxy is used because of the need to manage requests, connections, and other proxy-specific, resulting in performance-related challenges such as: 

• Queuing
• Backlogs
• Resource wastage

Businesses should carefully assess the impact on performance and ensure the selected reverse proxy solution can handle the anticipated demand.

Limited Protocol Support

Some reverse proxy servers only handle a few protocols, which limits the range of applications or services they can efficiently administer. 

Choose a reverse proxy solution that aligns with the specific requirements of the backend applications.

Debugging and Troubleshooting

The additional degree of abstraction introduced by a reverse proxy can make troubleshooting difficult.

Organizations must consider this and should be willing to invest time and resources in troubleshooting before employing a reverse proxy.

Compatibility Issues

Certain web pages or technologies that require specific prerequisites may cause reverse proxies to fail. To ensure compatibility, assess the proxy's capabilities through detailed testing.

Vendor Dependency

Implementing a reverse proxy solution often involves relying on a specific vendor or software. This dependency can limit flexibility and vendor lock-in. 

Organizations should carefully evaluate the long-term viability and support of the chosen reverse proxy solution to avoid potential issues in the future.

The threat posed by data storage

Leveraging IP monitoring and data encryption, reverse proxies can potentially retain sensitive data like passwords. This can be problematic if it’s run by a malicious party, considering that every 39 seconds, a hacking incident takes place.

In addition, since this information is extremely sensitive, they are responsible for maintaining the following:

• Confidentiality
• Integrity
• Availability

Here is a rundown of the upsides and downsides of using a reverse proxy:

Wrap-Up

A reverse proxy is a vital component of modern web infrastructure, offering numerous benefits such as load balancing, security, content caching, and SSL termination.

By intelligently managing incoming requests and distributing them to backend servers, reverse proxies optimize website delivery and ensure a seamless user experience. 

Understanding reverse proxies' capabilities and use cases of reverse proxies can empower businesses to make informed decisions when optimizing their web applications.