Many of us know about Web servers and APP servers, but few of us understand the relationship between them. In short, the WEB server transmits web pages for browser browsing, and the WEB server specifically handles HTTP requests. APP server provides methods that can be called by client applications. It provides business logic for applications through multiple protocols. that What is the special relationship between the web server and the APP server? Many people are still in a muddle about this, so today Micronet will take you to have a deep understanding.
1. Decomposition of WEB server
If the Web server receives an HTTP request, it returns an HTTP response, such as an HTML page. To process a request, the Web server can respond to static pages or pictures, perform page jumps, or delegate the task of generating dynamic responses to other programs, such as * GI scripts, JSP scripts, servlets scripts, ASP scripts, server-side JavaS * rip, or other server-side technologies. Whatever their purpose, these server-side programs usually generate HTML responses to enable browsers to browse.
It should be noted that the proxy model of the Web server is very simple. When a request is sent to the Web server, it simply passes the request to the program, which can handle the request well.
The web server only provides an environment for executing server-side programs and returning responses, not a place outside the function. The server program usually has the functions of transaction processing, database connection, information transmission, etc. Although the Web server does not support transaction processing or database connection pooling, it can configure different strategies, such as load balancing and buffering, to achieve fault tolerance and expansion. The cluster feature is often mistaken for the exclusive feature of the application server.
2. Decomposition of APP server
According to our definition, as an application server, it provides business logic to client applications through various protocols, including HTTP. The web server is mainly responsible for sending HTML to the browser for browsing, while the application server provides access to business logic so that client applications can use it. This business logic is used by applications, just like you call methods of objects (or functions in process languages). The client of an application server (with GUI) can run on a P *, a Web server, or even other application servers. This is not just a simple display tag, but also the information that shuttles back and forth between the APP server and its client. This message is program logic. Because this logic obtains the format of data and method calls instead of static HTML, the client can freely use this open business logic. In most cases, APP server exposes business logic to client applications through application program interface (API) of components, such as EJB component model based on J2EE application server.
In addition, the APP server can manage its own resources, such as security, transaction processing, resource pool and messages. Similar to the Web server, the application server is also configured with a variety of scalable and fault-tolerant technologies. Now, the WEB server can also send the XML payload to the server to enable it to process data and respond. The APP server also includes the WEB server function to some extent, which is the existing relationship between the WEB server and the APP server analyzed by Micronet, I believe that after reading this article, you should also have your own understanding of the two servers. If you have more questions about the server, please consult Micronet. Micronet is an IDC service provider focusing on server rental and hosting. With more than 10 years of industry experience, it is safe, stable, reliable and reassuring. It is a leading enterprise in the domestic IDC industry. It helps thousands of enterprises to achieve network informatization, 7 * 24 hours of manual service, after-sales care free, and has a good reputation.
