Five functions of reverse proxies

As a common network technology, reverse proxy has many roles and functions in Internet applications. Here are the five main roles of reverse proxies:

1, content caching: The reverse proxy server is located in front of the source server, it can cache the compressed and mirrored version of the website page. When the user sends a request, the reverse proxy can directly return the cached content without having to fetch the data from the source server each time.

With content caching, reverse proxies can significantly improve the speed of content delivery based on customer location. When the content requested by the user has been cached, the reverse proxy can immediately return the cached data to the user, reducing the wait time and network latency. This rapid response can greatly improve the user experience and improve the performance and usability of the website.

①What is the difference between proxy IP and ADSL dial-up IP switching?

In addition, content caching can reduce page load time. When a user accesses a web page, if the content of the web page has been cached, there is no need to request the source server again, but directly obtain the data from the cache. This saves network bandwidth and server resources, speeds up page loading, and provides faster response times.

Content caching plays an active role in both dynamic and static content. For static content, such as images, CSS, and JavaScript files, reverse proxies can cache these files, reducing the amount of data per request and improving transmission efficiency. For dynamic content, reverse proxies can cache dynamically generated pages so that subsequent requests can get responses directly from the cache, reducing the load on the source server.

2. Load balancing: As a load balancer, the reverse proxy can distribute user requests to multiple back-end servers to achieve balanced server load distribution.

With intelligent request distribution algorithms, reverse proxies can dynamically assign requests to idle or lightly loaded servers based on the load on the back-end servers. Common load balancing algorithms include polling, weighted polling, least connections, IP hashing, and so on. These algorithms can select the most suitable server to process user requests according to the performance, resource utilization and response time of the server, so as to achieve load balancing.

Load balancing can improve server utilization and ensure that each server can run properly. When the number of requests from users increases, load balancing automatically distributes the requests to servers with light loads to prevent performance degradation or service unavailability due to the overload of a server. By evenly distributing traffic, load balancers improve the reliability and stability of the overall system.

In addition, load balancing provides failover and high availability. When a server fails or is unavailable, the load balancer can automatically forward requests to other working servers to ensure service continuity and availability. This failover mechanism can effectively avoid single point of failure and improve the robustness of the system.

②Six common problems that web crawlers often encounter in the process of data crawling

3, IP mask: By passing all incoming traffic through the reverse proxy server, the server can terminate each connection and establish a new connection with the back-end server, so as to realize the proxy IP resolution of each user request. In this way, the real IP address of the proxy server is hidden, making direct IP attacks (such as DDoS attacks) more difficult.

4, data filtering: Since the reverse proxy server sits before the site server, all incoming application traffic can be filtered and cleaned. With effective data filtering, reverse proxies can improve protection against DDoS attacks and mitigate their impact. In addition, by placing a Web application firewall, users can also identify and isolate any malicious packets, including hacker requests and bots, thus improving the security of Web applications.

5. Encryption: Encrypting and decrypting Secure Socket Layer (SSL) communications for each user is less efficient for the source server. The reverse proxy server can help by implementing efficient encryption for each user. Reverse proxy servers can centrally handle encryption and decryption tasks, reducing the burden on the source server and improving overall performance and security.

To sum up, reverse proxies play an important role in content caching, load balancing, IP mask, data filtering and encryption. Through these roles, reverse proxies can improve the performance, security, and reliability of websites, providing users with a better access experience.