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This article mainly introduces "the overview of java reverse proxy and the working principle of reverse proxy server". In daily operation, I believe many people have doubts about the overview of java reverse proxy and the working principle of reverse proxy server. Xiaobian consulted all kinds of materials and sorted out simple and useful operation methods. I hope it will be helpful for you to answer the question of "the overview of java reverse proxy and how the reverse proxy server works". Next, please follow the editor to study!

I. Overview

Reverse proxy (Reverse Proxy) means that the proxy server accepts the connection request on the Internet, then forwards the request to the server on the internal network, and returns the result obtained from the server to the client requesting the connection on the Internet. At this time, the proxy server behaves as a server externally.

The usual proxy server is only used to proxy Internet connection requests from the internal network, and the client must specify a proxy server and send the http requests that should be sent directly to the Web server to the proxy server. When a proxy server can proxy hosts on the external network and access the internal network, this kind of proxy service is called reverse proxy service.

Second, the working principle of reverse proxy server

There are usually two models of reverse proxy server, which can be used as a stand-in for content servers or as a load balancer for content server clusters.

1. Act as a stand-in for the content server

If your content server has sensitive information that must be kept secure, such as a credit card number database, you can set up a proxy server outside the firewall as a stand-in for the content server. When an external client tries to access the content server, it is sent to the proxy server. The actual content is located on the content server and is secured inside the firewall. The proxy server is located outside the firewall and looks like a content server to the client.

When the client makes a request to the site, the request goes to the proxy server. The proxy server then sends the client's request to the content server through a specific path in the firewall. The content server then sends the results back to the proxy server through this channel. The proxy server sends the retrieved information to the client as if the proxy server were the actual content server (see figure 2). If the content server returns an error message, the proxy server intercepts the message and changes any URL listed in the header before sending the message to the client. This prevents external clients from getting the redirect URL of the internal content server.

In this way, the proxy server provides another barrier between secure databases and possible malicious attacks. In contrast to the situation where you have access to the entire database, even if the fluke attack succeeds, the perpetrator is at best limited to asking about the information involved in a single transaction. Unauthorized users cannot access the real content server because the firewall path only allows the proxy server access.

2. Load balancer as a content server

You can use multiple proxy servers within an organization to balance the network load among Web servers. In this model, you can take advantage of the caching feature of the proxy server to create a server pool for load balancing. At this point, the proxy server can be located on either side of the firewall. If the Web server receives a large number of requests every day, you can use a proxy server to share the load on the Web server and improve network access efficiency.

The proxy server acts as a mediator for requests sent by the client to the real server. The proxy server caches the requested document. If there is more than one proxy server, DNS can use "circular multiplexing" to select its IP address and randomly route the request. The client uses the same URL every time, but the route taken by the request may pass through a different proxy server each time.

Multiple proxy servers can be used to process requests to a high-usage content server, which has the advantage that the content server can handle a higher load and is more efficient than when it works alone. During the initial startup period, the proxy server retrieves documents from the content server for the first time, after which the number of requests to the content server decreases significantly.

At this point, the study on "the overview of java reverse proxy and how the reverse proxy server works" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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